glsl: implement shader sampler validation
Shader validation should fail if there are two samplers of different types
which reference the same texture unit. For example, if a cubemap sampler
and a 2D sampler both reference texture unit 0, that's invalid.
diff --git a/src/mesa/shader/shader_api.c b/src/mesa/shader/shader_api.c
index cf0a902..42b7fa7 100644
--- a/src/mesa/shader/shader_api.c
+++ b/src/mesa/shader/shader_api.c
@@ -1,6 +1,6 @@
/*
* Mesa 3-D graphics library
- * Version: 7.5
+ * Version: 7.6
*
* Copyright (C) 2004-2008 Brian Paul All Rights Reserved.
* Copyright (C) 2009 VMware, Inc. All Rights Reserved.
@@ -1966,19 +1966,74 @@
}
-static void
-_mesa_validate_program(GLcontext *ctx, GLuint program)
+/**
+ * Validate a program's samplers.
+ * Specifically, check that there aren't two samplers of different types
+ * pointing to the same texture unit.
+ * \return GL_TRUE if valid, GL_FALSE if invalid
+ */
+static GLboolean
+validate_samplers(GLcontext *ctx, const struct gl_program *prog, char *errMsg)
{
- struct gl_shader_program *shProg;
+ static const char *targetName[] = {
+ "TEXTURE_2D_ARRAY",
+ "TEXTURE_1D_ARRAY",
+ "TEXTURE_CUBE",
+ "TEXTURE_3D",
+ "TEXTURE_RECT",
+ "TEXTURE_2D",
+ "TEXTURE_1D",
+ };
+ GLint targetUsed[MAX_TEXTURE_IMAGE_UNITS];
+ GLbitfield samplersUsed = prog->SamplersUsed;
+ GLuint i;
- shProg = _mesa_lookup_shader_program_err(ctx, program, "glValidateProgram");
- if (!shProg) {
- return;
+ assert(Elements(targetName) == NUM_TEXTURE_TARGETS);
+
+ if (samplersUsed == 0x0)
+ return GL_TRUE;
+
+ for (i = 0; i < Elements(targetUsed); i++)
+ targetUsed[i] = -1;
+
+ /* walk over bits which are set in 'samplers' */
+ while (samplersUsed) {
+ GLuint unit;
+ gl_texture_index target;
+ GLint sampler = _mesa_ffs(samplersUsed) - 1;
+ assert(sampler >= 0);
+ assert(sampler < MAX_TEXTURE_IMAGE_UNITS);
+ unit = prog->SamplerUnits[sampler];
+ target = prog->SamplerTargets[sampler];
+ if (targetUsed[unit] != -1 && targetUsed[unit] != target) {
+ _mesa_snprintf(errMsg, 100,
+ "Texture unit %d is accessed both as %s and %s",
+ unit, targetName[targetUsed[unit]], targetName[target]);
+ return GL_FALSE;
+ }
+ targetUsed[unit] = target;
+ samplersUsed ^= (1 << sampler);
}
+ return GL_TRUE;
+}
+
+
+/**
+ * Do validation of the given shader program.
+ * \param errMsg returns error message if validation fails.
+ * \return GL_TRUE if valid, GL_FALSE if invalid (and set errMsg)
+ */
+GLboolean
+_mesa_validate_shader_program(GLcontext *ctx,
+ const struct gl_shader_program *shProg,
+ char *errMsg)
+{
+ const struct gl_vertex_program *vp = shProg->VertexProgram;
+ const struct gl_fragment_program *fp = shProg->FragmentProgram;
+
if (!shProg->LinkStatus) {
- shProg->Validated = GL_FALSE;
- return;
+ return GL_FALSE;
}
/* From the GL spec, a program is invalid if any of these are true:
@@ -1996,7 +2051,44 @@
image units allowed.
*/
- shProg->Validated = GL_TRUE;
+
+ /*
+ * Check: any two active samplers in the current program object are of
+ * different types, but refer to the same texture image unit,
+ */
+ if (vp && !validate_samplers(ctx, &vp->Base, errMsg)) {
+ return GL_FALSE;
+ }
+ if (fp && !validate_samplers(ctx, &fp->Base, errMsg)) {
+ return GL_FALSE;
+ }
+
+ return GL_TRUE;
+}
+
+
+/**
+ * Called via glValidateProgram()
+ */
+static void
+_mesa_validate_program(GLcontext *ctx, GLuint program)
+{
+ struct gl_shader_program *shProg;
+ char errMsg[100];
+
+ shProg = _mesa_lookup_shader_program_err(ctx, program, "glValidateProgram");
+ if (!shProg) {
+ return;
+ }
+
+ shProg->Validated = _mesa_validate_shader_program(ctx, shProg, errMsg);
+ if (!shProg->Validated) {
+ /* update info log */
+ if (shProg->InfoLog) {
+ _mesa_free(shProg->InfoLog);
+ }
+ shProg->InfoLog = _mesa_strdup(errMsg);
+ }
}