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gerrit-public.fairphone.software / platform / external / mesa3d / b0e0c26f0214739108dbf0d6ae9596caf13287ee / . / src / glsl / linker.cpp
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/*
* Copyright © 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file linker.cpp
* GLSL linker implementation
*
* Given a set of shaders that are to be linked to generate a final program,
* there are three distinct stages.
*
* In the first stage shaders are partitioned into groups based on the shader
* type. All shaders of a particular type (e.g., vertex shaders) are linked
* together.
*
* - Undefined references in each shader are resolve to definitions in
* another shader.
* - Types and qualifiers of uniforms, outputs, and global variables defined
* in multiple shaders with the same name are verified to be the same.
* - Initializers for uniforms and global variables defined
* in multiple shaders with the same name are verified to be the same.
*
* The result, in the terminology of the GLSL spec, is a set of shader
* executables for each processing unit.
*
* After the first stage is complete, a series of semantic checks are performed
* on each of the shader executables.
*
* - Each shader executable must define a \c main function.
* - Each vertex shader executable must write to \c gl_Position.
* - Each fragment shader executable must write to either \c gl_FragData or
* \c gl_FragColor.
*
* In the final stage individual shader executables are linked to create a
* complete exectuable.
*
* - Types of uniforms defined in multiple shader stages with the same name
* are verified to be the same.
* - Initializers for uniforms defined in multiple shader stages with the
* same name are verified to be the same.
* - Types and qualifiers of outputs defined in one stage are verified to
* be the same as the types and qualifiers of inputs defined with the same
* name in a later stage.
*
* \author Ian Romanick <ian.d.romanick@intel.com>
*/
#include "main/core.h"
#include "glsl_symbol_table.h"
#include "glsl_parser_extras.h"
#include "ir.h"
#include "program.h"
#include "program/hash_table.h"
#include "linker.h"
#include "link_varyings.h"
#include "ir_optimization.h"
#include "ir_rvalue_visitor.h"
#include "ir_uniform.h"
extern "C" {
#include "main/shaderobj.h"
#include "main/enums.h"
}
void linker_error(gl_shader_program *, const char *, ...);
namespace {
/**
* Visitor that determines whether or not a variable is ever written.
*/
class find_assignment_visitor : public ir_hierarchical_visitor {
public:
find_assignment_visitor(const char *name)
: name(name), found(false)
{
/* empty */
}
virtual ir_visitor_status visit_enter(ir_assignment *ir)
{
ir_variable *const var = ir->lhs->variable_referenced();
if (strcmp(name, var->name) == 0) {
found = true;
return visit_stop;
}
return visit_continue_with_parent;
}
virtual ir_visitor_status visit_enter(ir_call *ir)
{
foreach_two_lists(formal_node, &ir->callee->parameters,
actual_node, &ir->actual_parameters) {
ir_rvalue *param_rval = (ir_rvalue *) actual_node;
ir_variable *sig_param = (ir_variable *) formal_node;
if (sig_param->data.mode == ir_var_function_out ||
sig_param->data.mode == ir_var_function_inout) {
ir_variable *var = param_rval->variable_referenced();
if (var && strcmp(name, var->name) == 0) {
found = true;
return visit_stop;
}
}
}
if (ir->return_deref != NULL) {
ir_variable *const var = ir->return_deref->variable_referenced();
if (strcmp(name, var->name) == 0) {
found = true;
return visit_stop;
}
}
return visit_continue_with_parent;
}
bool variable_found()
{
return found;
}
private:
const char *name; /**< Find writes to a variable with this name. */
bool found; /**< Was a write to the variable found? */
};
/**
* Visitor that determines whether or not a variable is ever read.
*/
class find_deref_visitor : public ir_hierarchical_visitor {
public:
find_deref_visitor(const char *name)
: name(name), found(false)
{
/* empty */
}
virtual ir_visitor_status visit(ir_dereference_variable *ir)
{
if (strcmp(this->name, ir->var->name) == 0) {
this->found = true;
return visit_stop;
}
return visit_continue;
}
bool variable_found() const
{
return this->found;
}
private:
const char *name; /**< Find writes to a variable with this name. */
bool found; /**< Was a write to the variable found? */
};
class geom_array_resize_visitor : public ir_hierarchical_visitor {
public:
unsigned num_vertices;
gl_shader_program *prog;
geom_array_resize_visitor(unsigned num_vertices, gl_shader_program *prog)
{
this->num_vertices = num_vertices;
this->prog = prog;
}
virtual ~geom_array_resize_visitor()
{
/* empty */
}
virtual ir_visitor_status visit(ir_variable *var)
{
if (!var->type->is_array() || var->data.mode != ir_var_shader_in)
return visit_continue;
unsigned size = var->type->length;
/* Generate a link error if the shader has declared this array with an
* incorrect size.
*/
if (size && size != this->num_vertices) {
linker_error(this->prog, "size of array %s declared as %u, "
"but number of input vertices is %u\n",
var->name, size, this->num_vertices);
return visit_continue;
}
/* Generate a link error if the shader attempts to access an input
* array using an index too large for its actual size assigned at link
* time.
*/
if (var->data.max_array_access >= this->num_vertices) {
linker_error(this->prog, "geometry shader accesses element %i of "
"%s, but only %i input vertices\n",
var->data.max_array_access, var->name, this->num_vertices);
return visit_continue;
}
var->type = glsl_type::get_array_instance(var->type->element_type(),
this->num_vertices);
var->data.max_array_access = this->num_vertices - 1;
return visit_continue;
}
/* Dereferences of input variables need to be updated so that their type
* matches the newly assigned type of the variable they are accessing. */
virtual ir_visitor_status visit(ir_dereference_variable *ir)
{
ir->type = ir->var->type;
return visit_continue;
}
/* Dereferences of 2D input arrays need to be updated so that their type
* matches the newly assigned type of the array they are accessing. */
virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
{
const glsl_type *const vt = ir->array->type;
if (vt->is_array())
ir->type = vt->element_type();
return visit_continue;
}
};
/**
* Visitor that determines the highest stream id to which a (geometry) shader
* emits vertices. It also checks whether End{Stream}Primitive is ever called.
*/
class find_emit_vertex_visitor : public ir_hierarchical_visitor {
public:
find_emit_vertex_visitor(int max_allowed)
: max_stream_allowed(max_allowed),
invalid_stream_id(0),
invalid_stream_id_from_emit_vertex(false),
end_primitive_found(false),
uses_non_zero_stream(false)
{
/* empty */
}
virtual ir_visitor_status visit_leave(ir_emit_vertex *ir)
{
int stream_id = ir->stream_id();
if (stream_id < 0) {
invalid_stream_id = stream_id;
invalid_stream_id_from_emit_vertex = true;
return visit_stop;
}
if (stream_id > max_stream_allowed) {
invalid_stream_id = stream_id;
invalid_stream_id_from_emit_vertex = true;
return visit_stop;
}
if (stream_id != 0)
uses_non_zero_stream = true;
return visit_continue;
}
virtual ir_visitor_status visit_leave(ir_end_primitive *ir)
{
end_primitive_found = true;
int stream_id = ir->stream_id();
if (stream_id < 0) {
invalid_stream_id = stream_id;
invalid_stream_id_from_emit_vertex = false;
return visit_stop;
}
if (stream_id > max_stream_allowed) {
invalid_stream_id = stream_id;
invalid_stream_id_from_emit_vertex = false;
return visit_stop;
}
if (stream_id != 0)
uses_non_zero_stream = true;
return visit_continue;
}
bool error()
{
return invalid_stream_id != 0;
}
const char *error_func()
{
return invalid_stream_id_from_emit_vertex ?
"EmitStreamVertex" : "EndStreamPrimitive";
}
int error_stream()
{
return invalid_stream_id;
}
bool uses_streams()
{
return uses_non_zero_stream;
}
bool uses_end_primitive()
{
return end_primitive_found;
}
private:
int max_stream_allowed;
int invalid_stream_id;
bool invalid_stream_id_from_emit_vertex;
bool end_primitive_found;
bool uses_non_zero_stream;
};
} /* anonymous namespace */
void
linker_error(gl_shader_program *prog, const char *fmt, ...)
{
va_list ap;
ralloc_strcat(&prog->InfoLog, "error: ");
va_start(ap, fmt);
ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
va_end(ap);
prog->LinkStatus = false;
}
void
linker_warning(gl_shader_program *prog, const char *fmt, ...)
{
va_list ap;
ralloc_strcat(&prog->InfoLog, "warning: ");
va_start(ap, fmt);
ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
va_end(ap);
}
/**
* Given a string identifying a program resource, break it into a base name
* and an optional array index in square brackets.
*
* If an array index is present, \c out_base_name_end is set to point to the
* "[" that precedes the array index, and the array index itself is returned
* as a long.
*
* If no array index is present (or if the array index is negative or
* mal-formed), \c out_base_name_end, is set to point to the null terminator
* at the end of the input string, and -1 is returned.
*
* Only the final array index is parsed; if the string contains other array
* indices (or structure field accesses), they are left in the base name.
*
* No attempt is made to check that the base name is properly formed;
* typically the caller will look up the base name in a hash table, so
* ill-formed base names simply turn into hash table lookup failures.
*/
long
parse_program_resource_name(const GLchar *name,
const GLchar **out_base_name_end)
{
/* Section 7.3.1 ("Program Interfaces") of the OpenGL 4.3 spec says:
*
* "When an integer array element or block instance number is part of
* the name string, it will be specified in decimal form without a "+"
* or "-" sign or any extra leading zeroes. Additionally, the name
* string will not include white space anywhere in the string."
*/
const size_t len = strlen(name);
*out_base_name_end = name + len;
if (len == 0 || name[len-1] != ']')
return -1;
/* Walk backwards over the string looking for a non-digit character. This
* had better be the opening bracket for an array index.
*
* Initially, i specifies the location of the ']'. Since the string may
* contain only the ']' charcater, walk backwards very carefully.
*/
unsigned i;
for (i = len - 1; (i > 0) && isdigit(name[i-1]); --i)
/* empty */ ;
if ((i == 0) || name[i-1] != '[')
return -1;
long array_index = strtol(&name[i], NULL, 10);
if (array_index < 0)
return -1;
*out_base_name_end = name + (i - 1);
return array_index;
}
void
link_invalidate_variable_locations(exec_list *ir)
{
foreach_in_list(ir_instruction, node, ir) {
ir_variable *const var = node->as_variable();
if (var == NULL)
continue;
/* Only assign locations for variables that lack an explicit location.
* Explicit locations are set for all built-in variables, generic vertex
* shader inputs (via layout(location=...)), and generic fragment shader
* outputs (also via layout(location=...)).
*/
if (!var->data.explicit_location) {
var->data.location = -1;
var->data.location_frac = 0;
}
/* ir_variable::is_unmatched_generic_inout is used by the linker while
* connecting outputs from one stage to inputs of the next stage.
*
* There are two implicit assumptions here. First, we assume that any
* built-in variable (i.e., non-generic in or out) will have
* explicit_location set. Second, we assume that any generic in or out
* will not have explicit_location set.
*
* This second assumption will only be valid until
* GL_ARB_separate_shader_objects is supported. When that extension is
* implemented, this function will need some modifications.
*/
if (!var->data.explicit_location) {
var->data.is_unmatched_generic_inout = 1;
} else {
var->data.is_unmatched_generic_inout = 0;
}
}
}
/**
* Set UsesClipDistance and ClipDistanceArraySize based on the given shader.
*
* Also check for errors based on incorrect usage of gl_ClipVertex and
* gl_ClipDistance.
*
* Return false if an error was reported.
*/
static void
analyze_clip_usage(struct gl_shader_program *prog,
struct gl_shader *shader, GLboolean *UsesClipDistance,
GLuint *ClipDistanceArraySize)
{
*ClipDistanceArraySize = 0;
if (!prog->IsES && prog->Version >= 130) {
/* From section 7.1 (Vertex Shader Special Variables) of the
* GLSL 1.30 spec:
*
* "It is an error for a shader to statically write both
* gl_ClipVertex and gl_ClipDistance."
*
* This does not apply to GLSL ES shaders, since GLSL ES defines neither
* gl_ClipVertex nor gl_ClipDistance.
*/
find_assignment_visitor clip_vertex("gl_ClipVertex");
find_assignment_visitor clip_distance("gl_ClipDistance");
clip_vertex.run(shader->ir);
clip_distance.run(shader->ir);
if (clip_vertex.variable_found() && clip_distance.variable_found()) {
linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
"and `gl_ClipDistance'\n",
_mesa_shader_stage_to_string(shader->Stage));
return;
}
*UsesClipDistance = clip_distance.variable_found();
ir_variable *clip_distance_var =
shader->symbols->get_variable("gl_ClipDistance");
if (clip_distance_var)
*ClipDistanceArraySize = clip_distance_var->type->length;
} else {
*UsesClipDistance = false;
}
}
/**
* Verify that a vertex shader executable meets all semantic requirements.
*
* Also sets prog->Vert.UsesClipDistance and prog->Vert.ClipDistanceArraySize
* as a side effect.
*
* \param shader Vertex shader executable to be verified
*/
void
validate_vertex_shader_executable(struct gl_shader_program *prog,
struct gl_shader *shader)
{
if (shader == NULL)
return;
/* From the GLSL 1.10 spec, page 48:
*
* "The variable gl_Position is available only in the vertex
* language and is intended for writing the homogeneous vertex
* position. All executions of a well-formed vertex shader
* executable must write a value into this variable. [...] The
* variable gl_Position is available only in the vertex
* language and is intended for writing the homogeneous vertex
* position. All executions of a well-formed vertex shader
* executable must write a value into this variable."
*
* while in GLSL 1.40 this text is changed to:
*
* "The variable gl_Position is available only in the vertex
* language and is intended for writing the homogeneous vertex
* position. It can be written at any time during shader
* execution. It may also be read back by a vertex shader
* after being written. This value will be used by primitive
* assembly, clipping, culling, and other fixed functionality
* operations, if present, that operate on primitives after
* vertex processing has occurred. Its value is undefined if
* the vertex shader executable does not write gl_Position."
*
* All GLSL ES Versions are similar to GLSL 1.40--failing to write to
* gl_Position is not an error.
*/
if (prog->Version < (prog->IsES ? 300 : 140)) {
find_assignment_visitor find("gl_Position");
find.run(shader->ir);
if (!find.variable_found()) {
if (prog->IsES) {
linker_warning(prog,
"vertex shader does not write to `gl_Position'."
"It's value is undefined. \n");
} else {
linker_error(prog,
"vertex shader does not write to `gl_Position'. \n");
}
return;
}
}
analyze_clip_usage(prog, shader, &prog->Vert.UsesClipDistance,
&prog->Vert.ClipDistanceArraySize);
}
/**
* Verify that a fragment shader executable meets all semantic requirements
*
* \param shader Fragment shader executable to be verified
*/
void
validate_fragment_shader_executable(struct gl_shader_program *prog,
struct gl_shader *shader)
{
if (shader == NULL)
return;
find_assignment_visitor frag_color("gl_FragColor");
find_assignment_visitor frag_data("gl_FragData");
frag_color.run(shader->ir);
frag_data.run(shader->ir);
if (frag_color.variable_found() && frag_data.variable_found()) {
linker_error(prog, "fragment shader writes to both "
"`gl_FragColor' and `gl_FragData'\n");
}
}
/**
* Verify that a geometry shader executable meets all semantic requirements
*
* Also sets prog->Geom.VerticesIn, prog->Geom.UsesClipDistance, and
* prog->Geom.ClipDistanceArraySize as a side effect.
*
* \param shader Geometry shader executable to be verified
*/
void
validate_geometry_shader_executable(struct gl_shader_program *prog,
struct gl_shader *shader)
{
if (shader == NULL)
return;
unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
prog->Geom.VerticesIn = num_vertices;
analyze_clip_usage(prog, shader, &prog->Geom.UsesClipDistance,
&prog->Geom.ClipDistanceArraySize);
}
/**
* Check if geometry shaders emit to non-zero streams and do corresponding
* validations.
*/
static void
validate_geometry_shader_emissions(struct gl_context *ctx,
struct gl_shader_program *prog)
{
if (prog->_LinkedShaders[MESA_SHADER_GEOMETRY] != NULL) {
find_emit_vertex_visitor emit_vertex(ctx->Const.MaxVertexStreams - 1);
emit_vertex.run(prog->_LinkedShaders[MESA_SHADER_GEOMETRY]->ir);
if (emit_vertex.error()) {
linker_error(prog, "Invalid call %s(%d). Accepted values for the "
"stream parameter are in the range [0, %d].",
emit_vertex.error_func(),
emit_vertex.error_stream(),
ctx->Const.MaxVertexStreams - 1);
}
prog->Geom.UsesStreams = emit_vertex.uses_streams();
prog->Geom.UsesEndPrimitive = emit_vertex.uses_end_primitive();
/* From the ARB_gpu_shader5 spec:
*
* "Multiple vertex streams are supported only if the output primitive
* type is declared to be "points". A program will fail to link if it
* contains a geometry shader calling EmitStreamVertex() or
* EndStreamPrimitive() if its output primitive type is not "points".
*
* However, in the same spec:
*
* "The function EmitVertex() is equivalent to calling EmitStreamVertex()
* with <stream> set to zero."
*
* And:
*
* "The function EndPrimitive() is equivalent to calling
* EndStreamPrimitive() with <stream> set to zero."
*
* Since we can call EmitVertex() and EndPrimitive() when we output
* primitives other than points, calling EmitStreamVertex(0) or
* EmitEndPrimitive(0) should not produce errors. This it also what Nvidia
* does. Currently we only set prog->Geom.UsesStreams to TRUE when
* EmitStreamVertex() or EmitEndPrimitive() are called with a non-zero
* stream.
*/
if (prog->Geom.UsesStreams && prog->Geom.OutputType != GL_POINTS) {
linker_error(prog, "EmitStreamVertex(n) and EndStreamPrimitive(n) "
"with n>0 requires point output");
}
}
}
/**
* Perform validation of global variables used across multiple shaders
*/
void
cross_validate_globals(struct gl_shader_program *prog,
struct gl_shader **shader_list,
unsigned num_shaders,
bool uniforms_only)
{
/* Examine all of the uniforms in all of the shaders and cross validate
* them.
*/
glsl_symbol_table variables;
for (unsigned i = 0; i < num_shaders; i++) {
if (shader_list[i] == NULL)
continue;
foreach_in_list(ir_instruction, node, shader_list[i]->ir) {
ir_variable *const var = node->as_variable();
if (var == NULL)
continue;
if (uniforms_only && (var->data.mode != ir_var_uniform))
continue;
/* Don't cross validate temporaries that are at global scope. These
* will eventually get pulled into the shaders 'main'.
*/
if (var->data.mode == ir_var_temporary)
continue;
/* If a global with this name has already been seen, verify that the
* new instance has the same type. In addition, if the globals have
* initializers, the values of the initializers must be the same.
*/
ir_variable *const existing = variables.get_variable(var->name);
if (existing != NULL) {
if (var->type != existing->type) {
/* Consider the types to be "the same" if both types are arrays
* of the same type and one of the arrays is implicitly sized.
* In addition, set the type of the linked variable to the
* explicitly sized array.
*/
if (var->type->is_array()
&& existing->type->is_array()
&& (var->type->fields.array == existing->type->fields.array)
&& ((var->type->length == 0)
|| (existing->type->length == 0))) {
if (var->type->length != 0) {
existing->type = var->type;
}
} else if (var->type->is_record()
&& existing->type->is_record()
&& existing->type->record_compare(var->type)) {
existing->type = var->type;
} else {
linker_error(prog, "%s `%s' declared as type "
"`%s' and type `%s'\n",
mode_string(var),
var->name, var->type->name,
existing->type->name);
return;
}
}
if (var->data.explicit_location) {
if (existing->data.explicit_location
&& (var->data.location != existing->data.location)) {
linker_error(prog, "explicit locations for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
return;
}
existing->data.location = var->data.location;
existing->data.explicit_location = true;
}
/* From the GLSL 4.20 specification:
* "A link error will result if two compilation units in a program
* specify different integer-constant bindings for the same
* opaque-uniform name. However, it is not an error to specify a
* binding on some but not all declarations for the same name"
*/
if (var->data.explicit_binding) {
if (existing->data.explicit_binding &&
var->data.binding != existing->data.binding) {
linker_error(prog, "explicit bindings for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
return;
}
existing->data.binding = var->data.binding;
existing->data.explicit_binding = true;
}
if (var->type->contains_atomic() &&
var->data.atomic.offset != existing->data.atomic.offset) {
linker_error(prog, "offset specifications for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
return;
}
/* Validate layout qualifiers for gl_FragDepth.
*
* From the AMD/ARB_conservative_depth specs:
*
* "If gl_FragDepth is redeclared in any fragment shader in a
* program, it must be redeclared in all fragment shaders in
* that program that have static assignments to
* gl_FragDepth. All redeclarations of gl_FragDepth in all
* fragment shaders in a single program must have the same set
* of qualifiers."
*/
if (strcmp(var->name, "gl_FragDepth") == 0) {
bool layout_declared = var->data.depth_layout != ir_depth_layout_none;
bool layout_differs =
var->data.depth_layout != existing->data.depth_layout;
if (layout_declared && layout_differs) {
linker_error(prog,
"All redeclarations of gl_FragDepth in all "
"fragment shaders in a single program must have "
"the same set of qualifiers.");
}
if (var->data.used && layout_differs) {
linker_error(prog,
"If gl_FragDepth is redeclared with a layout "
"qualifier in any fragment shader, it must be "
"redeclared with the same layout qualifier in "
"all fragment shaders that have assignments to "
"gl_FragDepth");
}
}
/* Page 35 (page 41 of the PDF) of the GLSL 4.20 spec says:
*
* "If a shared global has multiple initializers, the
* initializers must all be constant expressions, and they
* must all have the same value. Otherwise, a link error will
* result. (A shared global having only one initializer does
* not require that initializer to be a constant expression.)"
*
* Previous to 4.20 the GLSL spec simply said that initializers
* must have the same value. In this case of non-constant
* initializers, this was impossible to determine. As a result,
* no vendor actually implemented that behavior. The 4.20
* behavior matches the implemented behavior of at least one other
* vendor, so we'll implement that for all GLSL versions.
*/
if (var->constant_initializer != NULL) {
if (existing->constant_initializer != NULL) {
if (!var->constant_initializer->has_value(existing->constant_initializer)) {
linker_error(prog, "initializers for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
return;
}
} else {
/* If the first-seen instance of a particular uniform did not
* have an initializer but a later instance does, copy the
* initializer to the version stored in the symbol table.
*/
/* FINISHME: This is wrong. The constant_value field should
* FINISHME: not be modified! Imagine a case where a shader
* FINISHME: without an initializer is linked in two different
* FINISHME: programs with shaders that have differing
* FINISHME: initializers. Linking with the first will
* FINISHME: modify the shader, and linking with the second
* FINISHME: will fail.
*/
existing->constant_initializer =
var->constant_initializer->clone(ralloc_parent(existing),
NULL);
}
}
if (var->data.has_initializer) {
if (existing->data.has_initializer
&& (var->constant_initializer == NULL
|| existing->constant_initializer == NULL)) {
linker_error(prog,
"shared global variable `%s' has multiple "
"non-constant initializers.\n",
var->name);
return;
}
/* Some instance had an initializer, so keep track of that. In
* this location, all sorts of initializers (constant or
* otherwise) will propagate the existence to the variable
* stored in the symbol table.
*/
existing->data.has_initializer = true;
}
if (existing->data.invariant != var->data.invariant) {
linker_error(prog, "declarations for %s `%s' have "
"mismatching invariant qualifiers\n",
mode_string(var), var->name);
return;
}
if (existing->data.centroid != var->data.centroid) {
linker_error(prog, "declarations for %s `%s' have "
"mismatching centroid qualifiers\n",
mode_string(var), var->name);
return;
}
if (existing->data.sample != var->data.sample) {
linker_error(prog, "declarations for %s `%s` have "
"mismatching sample qualifiers\n",
mode_string(var), var->name);
return;
}
} else
variables.add_variable(var);
}
}
}
/**
* Perform validation of uniforms used across multiple shader stages
*/
void
cross_validate_uniforms(struct gl_shader_program *prog)
{
cross_validate_globals(prog, prog->_LinkedShaders,
MESA_SHADER_STAGES, true);
}
/**
* Accumulates the array of prog->UniformBlocks and checks that all
* definitons of blocks agree on their contents.
*/
static bool
interstage_cross_validate_uniform_blocks(struct gl_shader_program *prog)
{
unsigned max_num_uniform_blocks = 0;
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
if (prog->_LinkedShaders[i])
max_num_uniform_blocks += prog->_LinkedShaders[i]->NumUniformBlocks;
}
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
struct gl_shader *sh = prog->_LinkedShaders[i];
prog->UniformBlockStageIndex[i] = ralloc_array(prog, int,
max_num_uniform_blocks);
for (unsigned int j = 0; j < max_num_uniform_blocks; j++)
prog->UniformBlockStageIndex[i][j] = -1;
if (sh == NULL)
continue;
for (unsigned int j = 0; j < sh->NumUniformBlocks; j++) {
int index = link_cross_validate_uniform_block(prog,
&prog->UniformBlocks,
&prog->NumUniformBlocks,
&sh->UniformBlocks[j]);
if (index == -1) {
linker_error(prog, "uniform block `%s' has mismatching definitions",
sh->UniformBlocks[j].Name);
return false;
}
prog->UniformBlockStageIndex[i][index] = j;
}
}
return true;
}
/**
* Populates a shaders symbol table with all global declarations
*/
static void
populate_symbol_table(gl_shader *sh)
{
sh->symbols = new(sh) glsl_symbol_table;
foreach_in_list(ir_instruction, inst, sh->ir) {
ir_variable *var;
ir_function *func;
if ((func = inst->as_function()) != NULL) {
sh->symbols->add_function(func);
} else if ((var = inst->as_variable()) != NULL) {
if (var->data.mode != ir_var_temporary)
sh->symbols->add_variable(var);
}
}
}
/**
* Remap variables referenced in an instruction tree
*
* This is used when instruction trees are cloned from one shader and placed in
* another. These trees will contain references to \c ir_variable nodes that
* do not exist in the target shader. This function finds these \c ir_variable
* references and replaces the references with matching variables in the target
* shader.
*
* If there is no matching variable in the target shader, a clone of the
* \c ir_variable is made and added to the target shader. The new variable is
* added to \b both the instruction stream and the symbol table.
*
* \param inst IR tree that is to be processed.
* \param symbols Symbol table containing global scope symbols in the
* linked shader.
* \param instructions Instruction stream where new variable declarations
* should be added.
*/
void
remap_variables(ir_instruction *inst, struct gl_shader *target,
hash_table *temps)
{
class remap_visitor : public ir_hierarchical_visitor {
public:
remap_visitor(struct gl_shader *target,
hash_table *temps)
{
this->target = target;
this->symbols = target->symbols;
this->instructions = target->ir;
this->temps = temps;
}
virtual ir_visitor_status visit(ir_dereference_variable *ir)
{
if (ir->var->data.mode == ir_var_temporary) {
ir_variable *var = (ir_variable *) hash_table_find(temps, ir->var);
assert(var != NULL);
ir->var = var;
return visit_continue;
}
ir_variable *const existing =
this->symbols->get_variable(ir->var->name);
if (existing != NULL)
ir->var = existing;
else {
ir_variable *copy = ir->var->clone(this->target, NULL);
this->symbols->add_variable(copy);
this->instructions->push_head(copy);
ir->var = copy;
}
return visit_continue;
}
private:
struct gl_shader *target;
glsl_symbol_table *symbols;
exec_list *instructions;
hash_table *temps;
};
remap_visitor v(target, temps);
inst->accept(&v);
}
/**
* Move non-declarations from one instruction stream to another
*
* The intended usage pattern of this function is to pass the pointer to the
* head sentinel of a list (i.e., a pointer to the list cast to an \c exec_node
* pointer) for \c last and \c false for \c make_copies on the first
* call. Successive calls pass the return value of the previous call for
* \c last and \c true for \c make_copies.
*
* \param instructions Source instruction stream
* \param last Instruction after which new instructions should be
* inserted in the target instruction stream
* \param make_copies Flag selecting whether instructions in \c instructions
* should be copied (via \c ir_instruction::clone) into the
* target list or moved.
*
* \return
* The new "last" instruction in the target instruction stream. This pointer
* is suitable for use as the \c last parameter of a later call to this
* function.
*/
exec_node *
move_non_declarations(exec_list *instructions, exec_node *last,
bool make_copies, gl_shader *target)
{
hash_table *temps = NULL;
if (make_copies)
temps = hash_table_ctor(0, hash_table_pointer_hash,
hash_table_pointer_compare);
foreach_in_list_safe(ir_instruction, inst, instructions) {
if (inst->as_function())
continue;
ir_variable *var = inst->as_variable();
if ((var != NULL) && (var->data.mode != ir_var_temporary))
continue;
assert(inst->as_assignment()
|| inst->as_call()
|| inst->as_if() /* for initializers with the ?: operator */
|| ((var != NULL) && (var->data.mode == ir_var_temporary)));
if (make_copies) {
inst = inst->clone(target, NULL);
if (var != NULL)
hash_table_insert(temps, inst, var);
else
remap_variables(inst, target, temps);
} else {
inst->remove();
}
last->insert_after(inst);
last = inst;
}
if (make_copies)
hash_table_dtor(temps);
return last;
}
/**
* Get the function signature for main from a shader
*/
ir_function_signature *
link_get_main_function_signature(gl_shader *sh)
{
ir_function *const f = sh->symbols->get_function("main");
if (f != NULL) {
exec_list void_parameters;
/* Look for the 'void main()' signature and ensure that it's defined.
* This keeps the linker from accidentally pick a shader that just
* contains a prototype for main.
*
* We don't have to check for multiple definitions of main (in multiple
* shaders) because that would have already been caught above.
*/
ir_function_signature *sig =
f->matching_signature(NULL, &void_parameters, false);
if ((sig != NULL) && sig->is_defined) {
return sig;
}
}
return NULL;
}
/**
* This class is only used in link_intrastage_shaders() below but declaring
* it inside that function leads to compiler warnings with some versions of
* gcc.
*/
class array_sizing_visitor : public ir_hierarchical_visitor {
public:
array_sizing_visitor()
: mem_ctx(ralloc_context(NULL)),
unnamed_interfaces(hash_table_ctor(0, hash_table_pointer_hash,
hash_table_pointer_compare))
{
}
~array_sizing_visitor()
{
hash_table_dtor(this->unnamed_interfaces);
ralloc_free(this->mem_ctx);
}
virtual ir_visitor_status visit(ir_variable *var)
{
fixup_type(&var->type, var->data.max_array_access);
if (var->type->is_interface()) {
if (interface_contains_unsized_arrays(var->type)) {
const glsl_type *new_type =
resize_interface_members(var->type,
var->get_max_ifc_array_access());
var->type = new_type;
var->change_interface_type(new_type);
}
} else if (var->type->is_array() &&
var->type->fields.array->is_interface()) {
if (interface_contains_unsized_arrays(var->type->fields.array)) {
const glsl_type *new_type =
resize_interface_members(var->type->fields.array,
var->get_max_ifc_array_access());
var->change_interface_type(new_type);
var->type =
glsl_type::get_array_instance(new_type, var->type->length);
}
} else if (const glsl_type *ifc_type = var->get_interface_type()) {
/* Store a pointer to the variable in the unnamed_interfaces
* hashtable.
*/
ir_variable **interface_vars = (ir_variable **)
hash_table_find(this->unnamed_interfaces, ifc_type);
if (interface_vars == NULL) {
interface_vars = rzalloc_array(mem_ctx, ir_variable *,
ifc_type->length);
hash_table_insert(this->unnamed_interfaces, interface_vars,
ifc_type);
}
unsigned index = ifc_type->field_index(var->name);
assert(index < ifc_type->length);
assert(interface_vars[index] == NULL);
interface_vars[index] = var;
}
return visit_continue;
}
/**
* For each unnamed interface block that was discovered while running the
* visitor, adjust the interface type to reflect the newly assigned array
* sizes, and fix up the ir_variable nodes to point to the new interface
* type.
*/
void fixup_unnamed_interface_types()
{
hash_table_call_foreach(this->unnamed_interfaces,
fixup_unnamed_interface_type, NULL);
}
private:
/**
* If the type pointed to by \c type represents an unsized array, replace
* it with a sized array whose size is determined by max_array_access.
*/
static void fixup_type(const glsl_type **type, unsigned max_array_access)
{
if ((*type)->is_unsized_array()) {
*type = glsl_type::get_array_instance((*type)->fields.array,
max_array_access + 1);
assert(*type != NULL);
}
}
/**
* Determine whether the given interface type contains unsized arrays (if
* it doesn't, array_sizing_visitor doesn't need to process it).
*/
static bool interface_contains_unsized_arrays(const glsl_type *type)
{
for (unsigned i = 0; i < type->length; i++) {
const glsl_type *elem_type = type->fields.structure[i].type;
if (elem_type->is_unsized_array())
return true;
}
return false;
}
/**
* Create a new interface type based on the given type, with unsized arrays
* replaced by sized arrays whose size is determined by
* max_ifc_array_access.
*/
static const glsl_type *
resize_interface_members(const glsl_type *type,
const unsigned *max_ifc_array_access)
{
unsigned num_fields = type->length;
glsl_struct_field *fields = new glsl_struct_field[num_fields];
memcpy(fields, type->fields.structure,
num_fields * sizeof(*fields));
for (unsigned i = 0; i < num_fields; i++) {
fixup_type(&fields[i].type, max_ifc_array_access[i]);
}
glsl_interface_packing packing =
(glsl_interface_packing) type->interface_packing;
const glsl_type *new_ifc_type =
glsl_type::get_interface_instance(fields, num_fields,
packing, type->name);
delete [] fields;
return new_ifc_type;
}
static void fixup_unnamed_interface_type(const void *key, void *data,
void *)
{
const glsl_type *ifc_type = (const glsl_type *) key;
ir_variable **interface_vars = (ir_variable **) data;
unsigned num_fields = ifc_type->length;
glsl_struct_field *fields = new glsl_struct_field[num_fields];
memcpy(fields, ifc_type->fields.structure,
num_fields * sizeof(*fields));
bool interface_type_changed = false;
for (unsigned i = 0; i < num_fields; i++) {
if (interface_vars[i] != NULL &&
fields[i].type != interface_vars[i]->type) {
fields[i].type = interface_vars[i]->type;
interface_type_changed = true;
}
}
if (!interface_type_changed) {
delete [] fields;
return;
}
glsl_interface_packing packing =
(glsl_interface_packing) ifc_type->interface_packing;
const glsl_type *new_ifc_type =
glsl_type::get_interface_instance(fields, num_fields, packing,
ifc_type->name);
delete [] fields;
for (unsigned i = 0; i < num_fields; i++) {
if (interface_vars[i] != NULL)
interface_vars[i]->change_interface_type(new_ifc_type);
}
}
/**
* Memory context used to allocate the data in \c unnamed_interfaces.
*/
void *mem_ctx;
/**
* Hash table from const glsl_type * to an array of ir_variable *'s
* pointing to the ir_variables constituting each unnamed interface block.
*/
hash_table *unnamed_interfaces;
};
/**
* Performs the cross-validation of layout qualifiers specified in
* redeclaration of gl_FragCoord for the attached fragment shaders,
* and propagates them to the linked FS and linked shader program.
*/
static void
link_fs_input_layout_qualifiers(struct gl_shader_program *prog,
struct gl_shader *linked_shader,
struct gl_shader **shader_list,
unsigned num_shaders)
{
linked_shader->redeclares_gl_fragcoord = false;
linked_shader->uses_gl_fragcoord = false;
linked_shader->origin_upper_left = false;
linked_shader->pixel_center_integer = false;
if (linked_shader->Stage != MESA_SHADER_FRAGMENT ||
(prog->Version < 150 && !prog->ARB_fragment_coord_conventions_enable))
return;
for (unsigned i = 0; i < num_shaders; i++) {
struct gl_shader *shader = shader_list[i];
/* From the GLSL 1.50 spec, page 39:
*
* "If gl_FragCoord is redeclared in any fragment shader in a program,
* it must be redeclared in all the fragment shaders in that program
* that have a static use gl_FragCoord."
*
* Exclude the case when one of the 'linked_shader' or 'shader' redeclares
* gl_FragCoord with no layout qualifiers but the other one doesn't
* redeclare it. If we strictly follow GLSL 1.50 spec's language, it
* should be a link error. But, generating link error for this case will
* be a wrong behaviour which spec didn't intend to do and it could also
* break some applications.
*/
if ((linked_shader->redeclares_gl_fragcoord
&& !shader->redeclares_gl_fragcoord
&& shader->uses_gl_fragcoord
&& (linked_shader->origin_upper_left
|| linked_shader->pixel_center_integer))
|| (shader->redeclares_gl_fragcoord
&& !linked_shader->redeclares_gl_fragcoord
&& linked_shader->uses_gl_fragcoord
&& (shader->origin_upper_left
|| shader->pixel_center_integer))) {
linker_error(prog, "fragment shader defined with conflicting "
"layout qualifiers for gl_FragCoord\n");
}
/* From the GLSL 1.50 spec, page 39:
*
* "All redeclarations of gl_FragCoord in all fragment shaders in a
* single program must have the same set of qualifiers."
*/
if (linked_shader->redeclares_gl_fragcoord && shader->redeclares_gl_fragcoord
&& (shader->origin_upper_left != linked_shader->origin_upper_left
|| shader->pixel_center_integer != linked_shader->pixel_center_integer)) {
linker_error(prog, "fragment shader defined with conflicting "
"layout qualifiers for gl_FragCoord\n");
}
/* Update the linked shader state.  Note that uses_gl_fragcoord should
* accumulate the results.  The other values should replace.  If there
* are multiple redeclarations, all the fields except uses_gl_fragcoord
* are already known to be the same.
*/
if (shader->redeclares_gl_fragcoord || shader->uses_gl_fragcoord) {
linked_shader->redeclares_gl_fragcoord =
shader->redeclares_gl_fragcoord;
linked_shader->uses_gl_fragcoord = linked_shader->uses_gl_fragcoord
|| shader->uses_gl_fragcoord;
linked_shader->origin_upper_left = shader->origin_upper_left;
linked_shader->pixel_center_integer = shader->pixel_center_integer;
}
}
}
/**
* Performs the cross-validation of geometry shader max_vertices and
* primitive type layout qualifiers for the attached geometry shaders,
* and propagates them to the linked GS and linked shader program.
*/
static void
link_gs_inout_layout_qualifiers(struct gl_shader_program *prog,
struct gl_shader *linked_shader,
struct gl_shader **shader_list,
unsigned num_shaders)
{
linked_shader->Geom.VerticesOut = 0;
linked_shader->Geom.Invocations = 0;
linked_shader->Geom.InputType = PRIM_UNKNOWN;
linked_shader->Geom.OutputType = PRIM_UNKNOWN;
/* No in/out qualifiers defined for anything but GLSL 1.50+
* geometry shaders so far.
*/
if (linked_shader->Stage != MESA_SHADER_GEOMETRY || prog->Version < 150)
return;
/* From the GLSL 1.50 spec, page 46:
*
* "All geometry shader output layout declarations in a program
* must declare the same layout and same value for
* max_vertices. There must be at least one geometry output
* layout declaration somewhere in a program, but not all
* geometry shaders (compilation units) are required to
* declare it."
*/
for (unsigned i = 0; i < num_shaders; i++) {
struct gl_shader *shader = shader_list[i];
if (shader->Geom.InputType != PRIM_UNKNOWN) {
if (linked_shader->Geom.InputType != PRIM_UNKNOWN &&
linked_shader->Geom.InputType != shader->Geom.InputType) {
linker_error(prog, "geometry shader defined with conflicting "
"input types\n");
return;
}
linked_shader->Geom.InputType = shader->Geom.InputType;
}
if (shader->Geom.OutputType != PRIM_UNKNOWN) {
if (linked_shader->Geom.OutputType != PRIM_UNKNOWN &&
linked_shader->Geom.OutputType != shader->Geom.OutputType) {
linker_error(prog, "geometry shader defined with conflicting "
"output types\n");
return;
}
linked_shader->Geom.OutputType = shader->Geom.OutputType;
}
if (shader->Geom.VerticesOut != 0) {
if (linked_shader->Geom.VerticesOut != 0 &&
linked_shader->Geom.VerticesOut != shader->Geom.VerticesOut) {
linker_error(prog, "geometry shader defined with conflicting "
"output vertex count (%d and %d)\n",
linked_shader->Geom.VerticesOut,
shader->Geom.VerticesOut);
return;
}
linked_shader->Geom.VerticesOut = shader->Geom.VerticesOut;
}
if (shader->Geom.Invocations != 0) {
if (linked_shader->Geom.Invocations != 0 &&
linked_shader->Geom.Invocations != shader->Geom.Invocations) {
linker_error(prog, "geometry shader defined with conflicting "
"invocation count (%d and %d)\n",
linked_shader->Geom.Invocations,
shader->Geom.Invocations);
return;
}
linked_shader->Geom.Invocations = shader->Geom.Invocations;
}
}
/* Just do the intrastage -> interstage propagation right now,
* since we already know we're in the right type of shader program
* for doing it.
*/
if (linked_shader->Geom.InputType == PRIM_UNKNOWN) {
linker_error(prog,
"geometry shader didn't declare primitive input type\n");
return;
}
prog->Geom.InputType = linked_shader->Geom.InputType;
if (linked_shader->Geom.OutputType == PRIM_UNKNOWN) {
linker_error(prog,
"geometry shader didn't declare primitive output type\n");
return;
}
prog->Geom.OutputType = linked_shader->Geom.OutputType;
if (linked_shader->Geom.VerticesOut == 0) {
linker_error(prog,
"geometry shader didn't declare max_vertices\n");
return;
}
prog->Geom.VerticesOut = linked_shader->Geom.VerticesOut;
if (linked_shader->Geom.Invocations == 0)
linked_shader->Geom.Invocations = 1;
prog->Geom.Invocations = linked_shader->Geom.Invocations;
}
/**
* Perform cross-validation of compute shader local_size_{x,y,z} layout
* qualifiers for the attached compute shaders, and propagate them to the
* linked CS and linked shader program.
*/
static void
link_cs_input_layout_qualifiers(struct gl_shader_program *prog,
struct gl_shader *linked_shader,
struct gl_shader **shader_list,
unsigned num_shaders)
{
for (int i = 0; i < 3; i++)
linked_shader->Comp.LocalSize[i] = 0;
/* This function is called for all shader stages, but it only has an effect
* for compute shaders.
*/
if (linked_shader->Stage != MESA_SHADER_COMPUTE)
return;
/* From the ARB_compute_shader spec, in the section describing local size
* declarations:
*
* If multiple compute shaders attached to a single program object
* declare local work-group size, the declarations must be identical;
* otherwise a link-time error results. Furthermore, if a program
* object contains any compute shaders, at least one must contain an
* input layout qualifier specifying the local work sizes of the
* program, or a link-time error will occur.
*/
for (unsigned sh = 0; sh < num_shaders; sh++) {
struct gl_shader *shader = shader_list[sh];
if (shader->Comp.LocalSize[0] != 0) {
if (linked_shader->Comp.LocalSize[0] != 0) {
for (int i = 0; i < 3; i++) {
if (linked_shader->Comp.LocalSize[i] !=
shader->Comp.LocalSize[i]) {
linker_error(prog, "compute shader defined with conflicting "
"local sizes\n");
return;
}
}
}
for (int i = 0; i < 3; i++)
linked_shader->Comp.LocalSize[i] = shader->Comp.LocalSize[i];
}
}
/* Just do the intrastage -> interstage propagation right now,
* since we already know we're in the right type of shader program
* for doing it.
*/
if (linked_shader->Comp.LocalSize[0] == 0) {
linker_error(prog, "compute shader didn't declare local size\n");
return;
}
for (int i = 0; i < 3; i++)
prog->Comp.LocalSize[i] = linked_shader->Comp.LocalSize[i];
}
/**
* Combine a group of shaders for a single stage to generate a linked shader
*
* \note
* If this function is supplied a single shader, it is cloned, and the new
* shader is returned.
*/
static struct gl_shader *
link_intrastage_shaders(void *mem_ctx,
struct gl_context *ctx,
struct gl_shader_program *prog,
struct gl_shader **shader_list,
unsigned num_shaders)
{
struct gl_uniform_block *uniform_blocks = NULL;
/* Check that global variables defined in multiple shaders are consistent.
*/
cross_validate_globals(prog, shader_list, num_shaders, false);
if (!prog->LinkStatus)
return NULL;
/* Check that interface blocks defined in multiple shaders are consistent.
*/
validate_intrastage_interface_blocks(prog, (const gl_shader **)shader_list,
num_shaders);
if (!prog->LinkStatus)
return NULL;
/* Link up uniform blocks defined within this stage. */
const unsigned num_uniform_blocks =
link_uniform_blocks(mem_ctx, prog, shader_list, num_shaders,
&uniform_blocks);
if (!prog->LinkStatus)
return NULL;
/* Check that there is only a single definition of each function signature
* across all shaders.
*/
for (unsigned i = 0; i < (num_shaders - 1); i++) {
foreach_in_list(ir_instruction, node, shader_list[i]->ir) {
ir_function *const f = node->as_function();
if (f == NULL)
continue;
for (unsigned j = i + 1; j < num_shaders; j++) {
ir_function *const other =
shader_list[j]->symbols->get_function(f->name);
/* If the other shader has no function (and therefore no function
* signatures) with the same name, skip to the next shader.
*/
if (other == NULL)
continue;
foreach_in_list(ir_function_signature, sig, &f->signatures) {
if (!sig->is_defined || sig->is_builtin())
continue;
ir_function_signature *other_sig =
other->exact_matching_signature(NULL, &sig->parameters);
if ((other_sig != NULL) && other_sig->is_defined
&& !other_sig->is_builtin()) {
linker_error(prog, "function `%s' is multiply defined",
f->name);
return NULL;
}
}
}
}
}
/* Find the shader that defines main, and make a clone of it.
*
* Starting with the clone, search for undefined references. If one is
* found, find the shader that defines it. Clone the reference and add
* it to the shader. Repeat until there are no undefined references or
* until a reference cannot be resolved.
*/
gl_shader *main = NULL;
for (unsigned i = 0; i < num_shaders; i++) {
if (link_get_main_function_signature(shader_list[i]) != NULL) {
main = shader_list[i];
break;
}
}
if (main == NULL) {
linker_error(prog, "%s shader lacks `main'\n",
_mesa_shader_stage_to_string(shader_list[0]->Stage));
return NULL;
}
gl_shader *linked = ctx->Driver.NewShader(NULL, 0, main->Type);
linked->ir = new(linked) exec_list;
clone_ir_list(mem_ctx, linked->ir, main->ir);
linked->UniformBlocks = uniform_blocks;
linked->NumUniformBlocks = num_uniform_blocks;
ralloc_steal(linked, linked->UniformBlocks);
link_fs_input_layout_qualifiers(prog, linked, shader_list, num_shaders);
link_gs_inout_layout_qualifiers(prog, linked, shader_list, num_shaders);
link_cs_input_layout_qualifiers(prog, linked, shader_list, num_shaders);
populate_symbol_table(linked);
/* The pointer to the main function in the final linked shader (i.e., the
* copy of the original shader that contained the main function).
*/
ir_function_signature *const main_sig =
link_get_main_function_signature(linked);
/* Move any instructions other than variable declarations or function
* declarations into main.
*/
exec_node *insertion_point =
move_non_declarations(linked->ir, (exec_node *) &main_sig->body, false,
linked);
for (unsigned i = 0; i < num_shaders; i++) {
if (shader_list[i] == main)
continue;
insertion_point = move_non_declarations(shader_list[i]->ir,
insertion_point, true, linked);
}
/* Check if any shader needs built-in functions. */
bool need_builtins = false;
for (unsigned i = 0; i < num_shaders; i++) {
if (shader_list[i]->uses_builtin_functions) {
need_builtins = true;
break;
}
}
bool ok;
if (need_builtins) {
/* Make a temporary array one larger than shader_list, which will hold
* the built-in function shader as well.
*/
gl_shader **linking_shaders = (gl_shader **)
calloc(num_shaders + 1, sizeof(gl_shader *));
ok = linking_shaders != NULL;
if (ok) {
memcpy(linking_shaders, shader_list, num_shaders * sizeof(gl_shader *));
linking_shaders[num_shaders] = _mesa_glsl_get_builtin_function_shader();
ok = link_function_calls(prog, linked, linking_shaders, num_shaders + 1);
free(linking_shaders);
} else {
_mesa_error_no_memory(__func__);
}
} else {
ok = link_function_calls(prog, linked, shader_list, num_shaders);
}
if (!ok) {
ctx->Driver.DeleteShader(ctx, linked);
return NULL;
}
/* At this point linked should contain all of the linked IR, so
* validate it to make sure nothing went wrong.
*/
validate_ir_tree(linked->ir);
/* Set the size of geometry shader input arrays */
if (linked->Stage == MESA_SHADER_GEOMETRY) {
unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
geom_array_resize_visitor input_resize_visitor(num_vertices, prog);
foreach_in_list(ir_instruction, ir, linked->ir) {
ir->accept(&input_resize_visitor);
}
}
if (ctx->Const.VertexID_is_zero_based)
lower_vertex_id(linked);
/* Make a pass over all variable declarations to ensure that arrays with
* unspecified sizes have a size specified. The size is inferred from the
* max_array_access field.
*/
array_sizing_visitor v;
v.run(linked->ir);
v.fixup_unnamed_interface_types();
return linked;
}
/**
* Update the sizes of linked shader uniform arrays to the maximum
* array index used.
*
* From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec:
*
* If one or more elements of an array are active,
* GetActiveUniform will return the name of the array in name,
* subject to the restrictions listed above. The type of the array
* is returned in type. The size parameter contains the highest
* array element index used, plus one. The compiler or linker
* determines the highest index used. There will be only one
* active uniform reported by the GL per uniform array.
*/
static void
update_array_sizes(struct gl_shader_program *prog)
{
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
if (prog->_LinkedShaders[i] == NULL)
continue;
foreach_in_list(ir_instruction, node, prog->_LinkedShaders[i]->ir) {
ir_variable *const var = node->as_variable();
if ((var == NULL) || (var->data.mode != ir_var_uniform) ||
!var->type->is_array())
continue;
/* GL_ARB_uniform_buffer_object says that std140 uniforms
* will not be eliminated. Since we always do std140, just
* don't resize arrays in UBOs.
*
* Atomic counters are supposed to get deterministic
* locations assigned based on the declaration ordering and
* sizes, array compaction would mess that up.
*/
if (var->is_in_uniform_block() || var->type->contains_atomic())
continue;
unsigned int size = var->data.max_array_access;
for (unsigned j = 0; j < MESA_SHADER_STAGES; j++) {
if (prog->_LinkedShaders[j] == NULL)
continue;
foreach_in_list(ir_instruction, node2, prog->_LinkedShaders[j]->ir) {
ir_variable *other_var = node2->as_variable();
if (!other_var)
continue;
if (strcmp(var->name, other_var->name) == 0 &&
other_var->data.max_array_access > size) {
size = other_var->data.max_array_access;
}
}
}
if (size + 1 != var->type->length) {
/* If this is a built-in uniform (i.e., it's backed by some
* fixed-function state), adjust the number of state slots to
* match the new array size. The number of slots per array entry
* is not known. It seems safe to assume that the total number of
* slots is an integer multiple of the number of array elements.
* Determine the number of slots per array element by dividing by
* the old (total) size.
*/
const unsigned num_slots = var->get_num_state_slots();
if (num_slots > 0) {
var->set_num_state_slots((size + 1)
* (num_slots / var->type->length));
}
var->type = glsl_type::get_array_instance(var->type->fields.array,
size + 1);
/* FINISHME: We should update the types of array
* dereferences of this variable now.
*/
}
}
}
}
/**
* Find a contiguous set of available bits in a bitmask.
*
* \param used_mask Bits representing used (1) and unused (0) locations
* \param needed_count Number of contiguous bits needed.
*
* \return
* Base location of the available bits on success or -1 on failure.
*/
int
find_available_slots(unsigned used_mask, unsigned needed_count)
{
unsigned needed_mask = (1 << needed_count) - 1;
const int max_bit_to_test = (8 * sizeof(used_mask)) - needed_count;
/* The comparison to 32 is redundant, but without it GCC emits "warning:
* cannot optimize possibly infinite loops" for the loop below.
*/
if ((needed_count == 0) || (max_bit_to_test < 0) || (max_bit_to_test > 32))
return -1;
for (int i = 0; i <= max_bit_to_test; i++) {
if ((needed_mask & ~used_mask) == needed_mask)
return i;
needed_mask <<= 1;
}
return -1;
}
/**
* Assign locations for either VS inputs or FS outputs
*
* \param prog Shader program whose variables need locations assigned
* \param target_index Selector for the program target to receive location
* assignmnets. Must be either \c MESA_SHADER_VERTEX or
* \c MESA_SHADER_FRAGMENT.
* \param max_index Maximum number of generic locations. This corresponds
* to either the maximum number of draw buffers or the
* maximum number of generic attributes.
*
* \return
* If locations are successfully assigned, true is returned. Otherwise an
* error is emitted to the shader link log and false is returned.
*/
bool
assign_attribute_or_color_locations(gl_shader_program *prog,
unsigned target_index,
unsigned max_index)
{
/* Mark invalid locations as being used.
*/
unsigned used_locations = (max_index >= 32)
? ~0 : ~((1 << max_index) - 1);
assert((target_index == MESA_SHADER_VERTEX)
|| (target_index == MESA_SHADER_FRAGMENT));
gl_shader *const sh = prog->_LinkedShaders[target_index];
if (sh == NULL)
return true;
/* Operate in a total of four passes.
*
* 1. Invalidate the location assignments for all vertex shader inputs.
*
* 2. Assign locations for inputs that have user-defined (via
* glBindVertexAttribLocation) locations and outputs that have
* user-defined locations (via glBindFragDataLocation).
*
* 3. Sort the attributes without assigned locations by number of slots
* required in decreasing order. Fragmentation caused by attribute
* locations assigned by the application may prevent large attributes
* from having enough contiguous space.
*
* 4. Assign locations to any inputs without assigned locations.
*/
const int generic_base = (target_index == MESA_SHADER_VERTEX)
? (int) VERT_ATTRIB_GENERIC0 : (int) FRAG_RESULT_DATA0;
const enum ir_variable_mode direction =
(target_index == MESA_SHADER_VERTEX)
? ir_var_shader_in : ir_var_shader_out;
/* Temporary storage for the set of attributes that need locations assigned.
*/
struct temp_attr {
unsigned slots;
ir_variable *var;
/* Used below in the call to qsort. */
static int compare(const void *a, const void *b)
{
const temp_attr *const l = (const temp_attr *) a;
const temp_attr *const r = (const temp_attr *) b;
/* Reversed because we want a descending order sort below. */
return r->slots - l->slots;
}
} to_assign[16];
unsigned num_attr = 0;
foreach_in_list(ir_instruction, node, sh->ir) {
ir_variable *const var = node->as_variable();
if ((var == NULL) || (var->data.mode != (unsigned) direction))
continue;
if (var->data.explicit_location) {
if ((var->data.location >= (int)(max_index + generic_base))
|| (var->data.location < 0)) {
linker_error(prog,
"invalid explicit location %d specified for `%s'\n",
(var->data.location < 0)
? var->data.location
: var->data.location - generic_base,
var->name);
return false;
}
} else if (target_index == MESA_SHADER_VERTEX) {
unsigned binding;
if (prog->AttributeBindings->get(binding, var->name)) {
assert(binding >= VERT_ATTRIB_GENERIC0);
var->data.location = binding;
var->data.is_unmatched_generic_inout = 0;
}
} else if (target_index == MESA_SHADER_FRAGMENT) {
unsigned binding;
unsigned index;
if (prog->FragDataBindings->get(binding, var->name)) {
assert(binding >= FRAG_RESULT_DATA0);
var->data.location = binding;
var->data.is_unmatched_generic_inout = 0;
if (prog->FragDataIndexBindings->get(index, var->name)) {
var->data.index = index;
}
}
}
/* If the variable is not a built-in and has a location statically
* assigned in the shader (presumably via a layout qualifier), make sure
* that it doesn't collide with other assigned locations. Otherwise,
* add it to the list of variables that need linker-assigned locations.
*/
const unsigned slots = var->type->count_attribute_slots();
if (var->data.location != -1) {
if (var->data.location >= generic_base && var->data.index < 1) {
/* From page 61 of the OpenGL 4.0 spec:
*
* "LinkProgram will fail if the attribute bindings assigned
* by BindAttribLocation do not leave not enough space to
* assign a location for an active matrix attribute or an
* active attribute array, both of which require multiple
* contiguous generic attributes."
*
* I think above text prohibits the aliasing of explicit and
* automatic assignments. But, aliasing is allowed in manual
* assignments of attribute locations. See below comments for
* the details.
*
* From OpenGL 4.0 spec, page 61:
*
* "It is possible for an application to bind more than one
* attribute name to the same location. This is referred to as
* aliasing. This will only work if only one of the aliased
* attributes is active in the executable program, or if no
* path through the shader consumes more than one attribute of
* a set of attributes aliased to the same location. A link
* error can occur if the linker determines that every path
* through the shader consumes multiple aliased attributes,
* but implementations are not required to generate an error
* in this case."
*
* From GLSL 4.30 spec, page 54:
*
* "A program will fail to link if any two non-vertex shader
* input variables are assigned to the same location. For
* vertex shaders, multiple input variables may be assigned
* to the same location using either layout qualifiers or via
* the OpenGL API. However, such aliasing is intended only to
* support vertex shaders where each execution path accesses
* at most one input per each location. Implementations are
* permitted, but not required, to generate link-time errors
* if they detect that every path through the vertex shader
* executable accesses multiple inputs assigned to any single
* location. For all shader types, a program will fail to link
* if explicit location assignments leave the linker unable
* to find space for other variables without explicit
* assignments."
*
* From OpenGL ES 3.0 spec, page 56:
*
* "Binding more than one attribute name to the same location
* is referred to as aliasing, and is not permitted in OpenGL
* ES Shading Language 3.00 vertex shaders. LinkProgram will
* fail when this condition exists. However, aliasing is
* possible in OpenGL ES Shading Language 1.00 vertex shaders.
* This will only work if only one of the aliased attributes
* is active in the executable program, or if no path through
* the shader consumes more than one attribute of a set of
* attributes aliased to the same location. A link error can
* occur if the linker determines that every path through the
* shader consumes multiple aliased attributes, but implemen-
* tations are not required to generate an error in this case."
*
* After looking at above references from OpenGL, OpenGL ES and
* GLSL specifications, we allow aliasing of vertex input variables
* in: OpenGL 2.0 (and above) and OpenGL ES 2.0.
*
* NOTE: This is not required by the spec but its worth mentioning
* here that we're not doing anything to make sure that no path
* through the vertex shader executable accesses multiple inputs
* assigned to any single location.
*/
/* Mask representing the contiguous slots that will be used by
* this attribute.
*/
const unsigned attr = var->data.location - generic_base;
const unsigned use_mask = (1 << slots) - 1;
const char *const string = (target_index == MESA_SHADER_VERTEX)
? "vertex shader input" : "fragment shader output";
/* Generate a link error if the requested locations for this
* attribute exceed the maximum allowed attribute location.
*/
if (attr + slots > max_index) {
linker_error(prog,
"insufficient contiguous locations "
"available for %s `%s' %d %d %d", string,
var->name, used_locations, use_mask, attr);
return false;
}
/* Generate a link error if the set of bits requested for this
* attribute overlaps any previously allocated bits.
*/
if ((~(use_mask << attr) & used_locations) != used_locations) {
if (target_index == MESA_SHADER_FRAGMENT ||
(prog->IsES && prog->Version >= 300)) {
linker_error(prog,
"overlapping location is assigned "
"to %s `%s' %d %d %d\n", string,
var->name, used_locations, use_mask, attr);
return false;
} else {
linker_warning(prog,
"overlapping location is assigned "
"to %s `%s' %d %d %d\n", string,
var->name, used_locations, use_mask, attr);
}
}
used_locations |= (use_mask << attr);
}
continue;
}
to_assign[num_attr].slots = slots;
to_assign[num_attr].var = var;
num_attr++;
}
/* If all of the attributes were assigned locations by the application (or
* are built-in attributes with fixed locations), return early. This should
* be the common case.
*/
if (num_attr == 0)
return true;
qsort(to_assign, num_attr, sizeof(to_assign[0]), temp_attr::compare);
if (target_index == MESA_SHADER_VERTEX) {
/* VERT_ATTRIB_GENERIC0 is a pseudo-alias for VERT_ATTRIB_POS. It can
* only be explicitly assigned by via glBindAttribLocation. Mark it as
* reserved to prevent it from being automatically allocated below.
*/
find_deref_visitor find("gl_Vertex");
find.run(sh->ir);
if (find.variable_found())
used_locations |= (1 << 0);
}
for (unsigned i = 0; i < num_attr; i++) {
/* Mask representing the contiguous slots that will be used by this
* attribute.
*/
const unsigned use_mask = (1 << to_assign[i].slots) - 1;
int location = find_available_slots(used_locations, to_assign[i].slots);
if (location < 0) {
const char *const string = (target_index == MESA_SHADER_VERTEX)
? "vertex shader input" : "fragment shader output";
linker_error(prog,
"insufficient contiguous locations "
"available for %s `%s'",
string, to_assign[i].var->name);
return false;
}
to_assign[i].var->data.location = generic_base + location;
to_assign[i].var->data.is_unmatched_generic_inout = 0;
used_locations |= (use_mask << location);
}
return true;
}
/**
* Demote shader inputs and outputs that are not used in other stages
*/
void
demote_shader_inputs_and_outputs(gl_shader *sh, enum ir_variable_mode mode)
{
foreach_in_list(ir_instruction, node, sh->ir) {
ir_variable *const var = node->as_variable();
if ((var == NULL) || (var->data.mode != int(mode)))
continue;
/* A shader 'in' or 'out' variable is only really an input or output if
* its value is used by other shader stages. This will cause the variable
* to have a location assigned.
*/
if (var->data.is_unmatched_generic_inout) {
assert(var->data.mode != ir_var_temporary);
var->data.mode = ir_var_auto;
}
}
}
/**
* Store the gl_FragDepth layout in the gl_shader_program struct.
*/
static void
store_fragdepth_layout(struct gl_shader_program *prog)
{
if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
return;
}
struct exec_list *ir = prog->_LinkedShaders[MESA_SHADER_FRAGMENT]->ir;
/* We don't look up the gl_FragDepth symbol directly because if
* gl_FragDepth is not used in the shader, it's removed from the IR.
* However, the symbol won't be removed from the symbol table.
*
* We're only interested in the cases where the variable is NOT removed
* from the IR.
*/
foreach_in_list(ir_instruction, node, ir) {
ir_variable *const var = node->as_variable();
if (var == NULL || var->data.mode != ir_var_shader_out) {
continue;
}
if (strcmp(var->name, "gl_FragDepth") == 0) {
switch (var->data.depth_layout) {
case ir_depth_layout_none:
prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_NONE;
return;
case ir_depth_layout_any:
prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_ANY;
return;
case ir_depth_layout_greater:
prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_GREATER;
return;
case ir_depth_layout_less:
prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_LESS;
return;
case ir_depth_layout_unchanged:
prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_UNCHANGED;
return;
default:
assert(0);
return;
}
}
}
}
/**
* Validate the resources used by a program versus the implementation limits
*/
static void
check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
{
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
struct gl_shader *sh = prog->_LinkedShaders[i];
if (sh == NULL)
continue;
if (sh->num_samplers > ctx->Const.Program[i].MaxTextureImageUnits) {
linker_error(prog, "Too many %s shader texture samplers",
_mesa_shader_stage_to_string(i));
}
if (sh->num_uniform_components >
ctx->Const.Program[i].MaxUniformComponents) {
if (ctx->Const.GLSLSkipStrictMaxUniformLimitCheck) {
linker_warning(prog, "Too many %s shader default uniform block "
"components, but the driver will try to optimize "
"them out; this is non-portable out-of-spec "
"behavior\n",
_mesa_shader_stage_to_string(i));
} else {
linker_error(prog, "Too many %s shader default uniform block "
"components",
_mesa_shader_stage_to_string(i));
}
}
if (sh->num_combined_uniform_components >
ctx->Const.Program[i].MaxCombinedUniformComponents) {
if (ctx->Const.GLSLSkipStrictMaxUniformLimitCheck) {
linker_warning(prog, "Too many %s shader uniform components, "
"but the driver will try to optimize them out; "
"this is non-portable out-of-spec behavior\n",
_mesa_shader_stage_to_string(i));
} else {
linker_error(prog, "Too many %s shader uniform components",
_mesa_shader_stage_to_string(i));
}
}
}
unsigned blocks[MESA_SHADER_STAGES] = {0};
unsigned total_uniform_blocks = 0;
for (unsigned i = 0; i < prog->NumUniformBlocks; i++) {
for (unsigned j = 0; j < MESA_SHADER_STAGES; j++) {
if (prog->UniformBlockStageIndex[j][i] != -1) {
blocks[j]++;
total_uniform_blocks++;
}
}
if (total_uniform_blocks > ctx->Const.MaxCombinedUniformBlocks) {
linker_error(prog, "Too many combined uniform blocks (%d/%d)",
prog->NumUniformBlocks,
ctx->Const.MaxCombinedUniformBlocks);
} else {
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
const unsigned max_uniform_blocks =
ctx->Const.Program[i].MaxUniformBlocks;
if (blocks[i] > max_uniform_blocks) {
linker_error(prog, "Too many %s uniform blocks (%d/%d)",
_mesa_shader_stage_to_string(i),
blocks[i],
max_uniform_blocks);
break;
}
}
}
}
}
/**
* Validate shader image resources.
*/
static void
check_image_resources(struct gl_context *ctx, struct gl_shader_program *prog)
{
unsigned total_image_units = 0;
unsigned fragment_outputs = 0;
if (!ctx->Extensions.ARB_shader_image_load_store)
return;
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
struct gl_shader *sh = prog->_LinkedShaders[i];
if (sh) {
if (sh->NumImages > ctx->Const.Program[i].MaxImageUniforms)
linker_error(prog, "Too many %s shader image uniforms",
_mesa_shader_stage_to_string(i));
total_image_units += sh->NumImages;
if (i == MESA_SHADER_FRAGMENT) {
foreach_in_list(ir_instruction, node, sh->ir) {
ir_variable *var = node->as_variable();
if (var && var->data.mode == ir_var_shader_out)
fragment_outputs += var->type->count_attribute_slots();
}
}
}
}
if (total_image_units > ctx->Const.MaxCombinedImageUniforms)
linker_error(prog, "Too many combined image uniforms");
if (total_image_units + fragment_outputs >
ctx->Const.MaxCombinedImageUnitsAndFragmentOutputs)
linker_error(prog, "Too many combined image uniforms and fragment outputs");
}
/**
* Initializes explicit location slots to INACTIVE_UNIFORM_EXPLICIT_LOCATION
* for a variable, checks for overlaps between other uniforms using explicit
* locations.
*/
static bool
reserve_explicit_locations(struct gl_shader_program *prog,
string_to_uint_map *map, ir_variable *var)
{
unsigned slots = var->type->uniform_locations();
unsigned max_loc = var->data.location + slots - 1;
/* Resize remap table if locations do not fit in the current one. */
if (max_loc + 1 > prog->NumUniformRemapTable) {
prog->UniformRemapTable =
reralloc(prog, prog->UniformRemapTable,
gl_uniform_storage *,
max_loc + 1);
if (!prog->UniformRemapTable) {
linker_error(prog, "Out of memory during linking.");
return false;
}
/* Initialize allocated space. */
for (unsigned i = prog->NumUniformRemapTable; i < max_loc + 1; i++)
prog->UniformRemapTable[i] = NULL;
prog->NumUniformRemapTable = max_loc + 1;
}
for (unsigned i = 0; i < slots; i++) {
unsigned loc = var->data.location + i;
/* Check if location is already used. */
if (prog->UniformRemapTable[loc] == INACTIVE_UNIFORM_EXPLICIT_LOCATION) {
/* Possibly same uniform from a different stage, this is ok. */
unsigned hash_loc;
if (map->get(hash_loc, var->name) && hash_loc == loc - i)
continue;
/* ARB_explicit_uniform_location specification states:
*
* "No two default-block uniform variables in the program can have
* the same location, even if they are unused, otherwise a compiler
* or linker error will be generated."
*/
linker_error(prog,
"location qualifier for uniform %s overlaps"
"previously used location",
var->name);
return false;
}
/* Initialize location as inactive before optimization
* rounds and location assignment.
*/
prog->UniformRemapTable[loc] = INACTIVE_UNIFORM_EXPLICIT_LOCATION;
}
/* Note, base location used for arrays. */
map->put(var->data.location, var->name);
return true;
}
/**
* Check and reserve all explicit uniform locations, called before
* any optimizations happen to handle also inactive uniforms and
* inactive array elements that may get trimmed away.
*/
static void
check_explicit_uniform_locations(struct gl_context *ctx,
struct gl_shader_program *prog)
{
if (!ctx->Extensions.ARB_explicit_uniform_location)
return;
/* This map is used to detect if overlapping explicit locations
* occur with the same uniform (from different stage) or a different one.
*/
string_to_uint_map *uniform_map = new string_to_uint_map;
if (!uniform_map) {
linker_error(prog, "Out of memory during linking.");
return;
}
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
struct gl_shader *sh = prog->_LinkedShaders[i];
if (!sh)
continue;
foreach_in_list(ir_instruction, node, sh->ir) {
ir_variable *var = node->as_variable();
if ((var && var->data.mode == ir_var_uniform) &&
var->data.explicit_location) {
if (!reserve_explicit_locations(prog, uniform_map, var)) {
delete uniform_map;
return;
}
}
}
}
delete uniform_map;
}
void
link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
{
tfeedback_decl *tfeedback_decls = NULL;
unsigned num_tfeedback_decls = prog->TransformFeedback.NumVarying;
void *mem_ctx = ralloc_context(NULL); // temporary linker context
prog->LinkStatus = true; /* All error paths will set this to false */
prog->Validated = false;
prog->_Used = false;
prog->ARB_fragment_coord_conventions_enable = false;
/* Separate the shaders into groups based on their type.
*/
struct gl_shader **shader_list[MESA_SHADER_STAGES];
unsigned num_shaders[MESA_SHADER_STAGES];
for (int i = 0; i < MESA_SHADER_STAGES; i++) {
shader_list[i] = (struct gl_shader **)
calloc(prog->NumShaders, sizeof(struct gl_shader *));
num_shaders[i] = 0;
}
unsigned min_version = UINT_MAX;
unsigned max_version = 0;
const bool is_es_prog =
(prog->NumShaders > 0 && prog->Shaders[0]->IsES) ? true : false;
for (unsigned i = 0; i < prog->NumShaders; i++) {
min_version = MIN2(min_version, prog->Shaders[i]->Version);
max_version = MAX2(max_version, prog->Shaders[i]->Version);
if (prog->Shaders[i]->IsES != is_es_prog) {
linker_error(prog, "all shaders must use same shading "
"language version\n");
goto done;
}
prog->ARB_fragment_coord_conventions_enable |=
prog->Shaders[i]->ARB_fragment_coord_conventions_enable;
gl_shader_stage shader_type = prog->Shaders[i]->Stage;
shader_list[shader_type][num_shaders[shader_type]] = prog->Shaders[i];
num_shaders[shader_type]++;
}
/* In desktop GLSL, different shader versions may be linked together. In
* GLSL ES, all shader versions must be the same.
*/
if (is_es_prog && min_version != max_version) {
linker_error(prog, "all shaders must use same shading "
"language version\n");
goto done;
}
prog->Version = max_version;
prog->IsES = is_es_prog;
/* Geometry shaders have to be linked with vertex shaders.
*/
if (num_shaders[MESA_SHADER_GEOMETRY] > 0 &&
num_shaders[MESA_SHADER_VERTEX] == 0 &&
!prog->SeparateShader) {
linker_error(prog, "Geometry shader must be linked with "
"vertex shader\n");
goto done;
}
/* Compute shaders have additional restrictions. */
if (num_shaders[MESA_SHADER_COMPUTE] > 0 &&
num_shaders[MESA_SHADER_COMPUTE] != prog->NumShaders) {
linker_error(prog, "Compute shaders may not be linked with any other "
"type of shader\n");
}
for (unsigned int i = 0; i < MESA_SHADER_STAGES; i++) {
if (prog->_LinkedShaders[i] != NULL)
ctx->Driver.DeleteShader(ctx, prog->_LinkedShaders[i]);
prog->_LinkedShaders[i] = NULL;
}
/* Link all shaders for a particular stage and validate the result.
*/
for (int stage = 0; stage < MESA_SHADER_STAGES; stage++) {
if (num_shaders[stage] > 0) {
gl_shader *const sh =
link_intrastage_shaders(mem_ctx, ctx, prog, shader_list[stage],
num_shaders[stage]);
if (!prog->LinkStatus)
goto done;
switch (stage) {
case MESA_SHADER_VERTEX:
validate_vertex_shader_executable(prog, sh);
break;
case MESA_SHADER_GEOMETRY:
validate_geometry_shader_executable(prog, sh);
break;
case MESA_SHADER_FRAGMENT:
validate_fragment_shader_executable(prog, sh);
break;
}
if (!prog->LinkStatus)
goto done;
_mesa_reference_shader(ctx, &prog->_LinkedShaders[stage], sh);
}
}
if (num_shaders[MESA_SHADER_GEOMETRY] > 0)
prog->LastClipDistanceArraySize = prog->Geom.ClipDistanceArraySize;
else if (num_shaders[MESA_SHADER_VERTEX] > 0)
prog->LastClipDistanceArraySize = prog->Vert.ClipDistanceArraySize;
else
prog->LastClipDistanceArraySize = 0; /* Not used */
/* Here begins the inter-stage linking phase. Some initial validation is
* performed, then locations are assigned for uniforms, attributes, and
* varyings.
*/
cross_validate_uniforms(prog);
if (!prog->LinkStatus)
goto done;
unsigned prev;
for (prev = 0; prev <= MESA_SHADER_FRAGMENT; prev++) {
if (prog->_LinkedShaders[prev] != NULL)
break;
}
check_explicit_uniform_locations(ctx, prog);
if (!prog->LinkStatus)
goto done;
/* Validate the inputs of each stage with the output of the preceding
* stage.
*/
for (unsigned i = prev + 1; i <= MESA_SHADER_FRAGMENT; i++) {
if (prog->_LinkedShaders[i] == NULL)
continue;
validate_interstage_inout_blocks(prog, prog->_LinkedShaders[prev],
prog->_LinkedShaders[i]);
if (!prog->LinkStatus)
goto done;
cross_validate_outputs_to_inputs(prog,
prog->_LinkedShaders[prev],
prog->_LinkedShaders[i]);
if (!prog->LinkStatus)
goto done;
prev = i;
}
/* Cross-validate uniform blocks between shader stages */
validate_interstage_uniform_blocks(prog, prog->_LinkedShaders,
MESA_SHADER_STAGES);
if (!prog->LinkStatus)
goto done;
for (unsigned int i = 0; i < MESA_SHADER_STAGES; i++) {
if (prog->_LinkedShaders[i] != NULL)
lower_named_interface_blocks(mem_ctx, prog->_LinkedShaders[i]);
}
/* Implement the GLSL 1.30+ rule for discard vs infinite loops Do
* it before optimization because we want most of the checks to get
* dropped thanks to constant propagation.
*
* This rule also applies to GLSL ES 3.00.
*/
if (max_version >= (is_es_prog ? 300 : 130)) {
struct gl_shader *sh = prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
if (sh) {
lower_discard_flow(sh->ir);
}
}
if (!interstage_cross_validate_uniform_blocks(prog))
goto done;
/* Do common optimization before assigning storage for attributes,
* uniforms, and varyings. Later optimization could possibly make
* some of that unused.
*/
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
if (prog->_LinkedShaders[i] == NULL)
continue;
detect_recursion_linked(prog, prog->_LinkedShaders[i]->ir);
if (!prog->LinkStatus)
goto done;
if (ctx->Const.ShaderCompilerOptions[i].LowerClipDistance) {
lower_clip_distance(prog->_LinkedShaders[i]);
}
while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false,
&ctx->Const.ShaderCompilerOptions[i],
ctx->Const.NativeIntegers))
;
}
/* Check and validate stream emissions in geometry shaders */
validate_geometry_shader_emissions(ctx, prog);
/* Mark all generic shader inputs and outputs as unpaired. */
for (unsigned i = MESA_SHADER_VERTEX; i <= MESA_SHADER_FRAGMENT; i++) {
if (prog->_LinkedShaders[i] != NULL) {
link_invalidate_variable_locations(prog->_LinkedShaders[i]->ir);
}
}
/* FINISHME: The value of the max_attribute_index parameter is
* FINISHME: implementation dependent based on the value of
* FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be
* FINISHME: at least 16, so hardcode 16 for now.
*/
if (!assign_attribute_or_color_locations(prog, MESA_SHADER_VERTEX, 16)) {
goto done;
}
if (!assign_attribute_or_color_locations(prog, MESA_SHADER_FRAGMENT, MAX2(ctx->Const.MaxDrawBuffers, ctx->Const.MaxDualSourceDrawBuffers))) {
goto done;
}
unsigned first;
for (first = 0; first <= MESA_SHADER_FRAGMENT; first++) {
if (prog->_LinkedShaders[first] != NULL)
break;
}
if (num_tfeedback_decls != 0) {
/* From GL_EXT_transform_feedback:
* A program will fail to link if:
*
* * the <count> specified by TransformFeedbackVaryingsEXT is
* non-zero, but the program object has no vertex or geometry
* shader;
*/
if (first == MESA_SHADER_FRAGMENT) {
linker_error(prog, "Transform feedback varyings specified, but "
"no vertex or geometry shader is present.");
goto done;
}
tfeedback_decls = ralloc_array(mem_ctx, tfeedback_decl,
prog->TransformFeedback.NumVarying);
if (!parse_tfeedback_decls(ctx, prog, mem_ctx, num_tfeedback_decls,
prog->TransformFeedback.VaryingNames,
tfeedback_decls))
goto done;
}
/* Linking the stages in the opposite order (from fragment to vertex)
* ensures that inter-shader outputs written to in an earlier stage are
* eliminated if they are (transitively) not used in a later stage.
*/
int last, next;
for (last = MESA_SHADER_FRAGMENT; last >= 0; last--) {
if (prog->_LinkedShaders[last] != NULL)
break;
}
if (last >= 0 && last < MESA_SHADER_FRAGMENT) {
gl_shader *const sh = prog->_LinkedShaders[last];
if (num_tfeedback_decls != 0 || prog->SeparateShader) {
/* There was no fragment shader, but we still have to assign varying
* locations for use by transform feedback.
*/
if (!assign_varying_locations(ctx, mem_ctx, prog,
sh, NULL,
num_tfeedback_decls, tfeedback_decls,
0))
goto done;
}
do_dead_builtin_varyings(ctx, sh, NULL,
num_tfeedback_decls, tfeedback_decls);
if (!prog->SeparateShader)
demote_shader_inputs_and_outputs(sh, ir_var_shader_out);
/* Eliminate code that is now dead due to unused outputs being demoted.
*/
while (do_dead_code(sh->ir, false))
;
}
else if (first == MESA_SHADER_FRAGMENT) {
/* If the program only contains a fragment shader...
*/
gl_shader *const sh = prog->_LinkedShaders[first];
do_dead_builtin_varyings(ctx, NULL, sh,
num_tfeedback_decls, tfeedback_decls);
if (prog->SeparateShader) {
if (!assign_varying_locations(ctx, mem_ctx, prog,
NULL /* producer */,
sh /* consumer */,
0 /* num_tfeedback_decls */,
NULL /* tfeedback_decls */,
0 /* gs_input_vertices */))
goto done;
} else
demote_shader_inputs_and_outputs(sh, ir_var_shader_in);
while (do_dead_code(sh->ir, false))
;
}
next = last;
for (int i = next - 1; i >= 0; i--) {
if (prog->_LinkedShaders[i] == NULL)
continue;
gl_shader *const sh_i = prog->_LinkedShaders[i];
gl_shader *const sh_next = prog->_LinkedShaders[next];
unsigned gs_input_vertices =
next == MESA_SHADER_GEOMETRY ? prog->Geom.VerticesIn : 0;
if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next,
next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
tfeedback_decls, gs_input_vertices))
goto done;
do_dead_builtin_varyings(ctx, sh_i, sh_next,
next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
tfeedback_decls);
demote_shader_inputs_and_outputs(sh_i, ir_var_shader_out);
demote_shader_inputs_and_outputs(sh_next, ir_var_shader_in);
/* Eliminate code that is now dead due to unused outputs being demoted.
*/
while (do_dead_code(sh_i->ir, false))
;
while (do_dead_code(sh_next->ir, false))
;
/* This must be done after all dead varyings are eliminated. */
if (!check_against_output_limit(ctx, prog, sh_i))
goto done;
if (!check_against_input_limit(ctx, prog, sh_next))
goto done;
next = i;
}
if (!store_tfeedback_info(ctx, prog, num_tfeedback_decls, tfeedback_decls))
goto done;
update_array_sizes(prog);
link_assign_uniform_locations(prog, ctx->Const.UniformBooleanTrue);
link_assign_atomic_counter_resources(ctx, prog);
store_fragdepth_layout(prog);
check_resources(ctx, prog);
check_image_resources(ctx, prog);
link_check_atomic_counter_resources(ctx, prog);
if (!prog->LinkStatus)
goto done;
/* OpenGL ES requires that a vertex shader and a fragment shader both be
* present in a linked program. GL_ARB_ES2_compatibility doesn't say
* anything about shader linking when one of the shaders (vertex or
* fragment shader) is absent. So, the extension shouldn't change the
* behavior specified in GLSL specification.
*/
if (!prog->SeparateShader && ctx->API == API_OPENGLES2) {
if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) {
linker_error(prog, "program lacks a vertex shader\n");
} else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
linker_error(prog, "program lacks a fragment shader\n");
}
}
/* FINISHME: Assign fragment shader output locations. */
done:
for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
free(shader_list[i]);
if (prog->_LinkedShaders[i] == NULL)
continue;
/* Do a final validation step to make sure that the IR wasn't
* invalidated by any modifications performed after intrastage linking.
*/
validate_ir_tree(prog->_LinkedShaders[i]->ir);
/* Retain any live IR, but trash the rest. */
reparent_ir(prog->_LinkedShaders[i]->ir, prog->_LinkedShaders[i]->ir);
/* The symbol table in the linked shaders may contain references to
* variables that were removed (e.g., unused uniforms). Since it may
* contain junk, there is no possible valid use. Delete it and set the
* pointer to NULL.
*/
delete prog->_LinkedShaders[i]->symbols;
prog->_LinkedShaders[i]->symbols = NULL;
}
ralloc_free(mem_ctx);
}