linker: Initial implementation of interstage input / output validation
diff --git a/linker.cpp b/linker.cpp
index a7eff55..7b1838a 100644
--- a/linker.cpp
+++ b/linker.cpp
@@ -224,6 +224,100 @@
}
+/**
+ * Validate that outputs from one stage match inputs of another
+ */
+bool
+cross_validate_outputs_to_inputs(glsl_shader *producer, glsl_shader *consumer)
+{
+ glsl_symbol_table parameters;
+ /* FINISHME: Figure these out dynamically. */
+ const char *const producer_stage = "vertex";
+ const char *const consumer_stage = "fragment";
+
+ /* Find all shader outputs in the "producer" stage.
+ */
+ foreach_list(node, &producer->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ /* FINISHME: For geometry shaders, this should also look for inout
+ * FINISHME: variables.
+ */
+ if ((var == NULL) || (var->mode != ir_var_out))
+ continue;
+
+ parameters.add_variable(var->name, var);
+ }
+
+
+ /* Find all shader inputs in the "consumer" stage. Any variables that have
+ * matching outputs already in the symbol table must have the same type and
+ * qualifiers.
+ */
+ foreach_list(node, &consumer->ir) {
+ ir_variable *const input = ((ir_instruction *) node)->as_variable();
+
+ /* FINISHME: For geometry shaders, this should also look for inout
+ * FINISHME: variables.
+ */
+ if ((input == NULL) || (input->mode != ir_var_in))
+ continue;
+
+ ir_variable *const output = parameters.get_variable(input->name);
+ if (output != NULL) {
+ /* Check that the types match between stages.
+ */
+ if (input->type != output->type) {
+ printf("error: %s shader output `%s' delcared as type `%s', but "
+ "%s shader input declared as type `%s'\n",
+ producer_stage, output->name, output->type->name,
+ consumer_stage, input->type->name);
+ return false;
+ }
+
+ /* Check that all of the qualifiers match between stages.
+ */
+ if (input->centroid != output->centroid) {
+ printf("error: %s shader output `%s' %s centroid qualifier, but "
+ "%s shader input %s centroid qualifier\n",
+ producer_stage,
+ output->name,
+ (output->centroid) ? "has" : "lacks",
+ consumer_stage,
+ (input->centroid) ? "has" : "lacks");
+ return false;
+ }
+
+ if (input->invariant != output->invariant) {
+ printf("error: %s shader output `%s' %s invariant qualifier, but "
+ "%s shader input %s invariant qualifier\n",
+ producer_stage,
+ output->name,
+ (output->invariant) ? "has" : "lacks",
+ consumer_stage,
+ (input->invariant) ? "has" : "lacks");
+ return false;
+ }
+
+ if (input->interpolation != output->interpolation) {
+ printf("error: %s shader output `%s' specifies %s interpolation "
+ "qualifier, "
+ "but %s shader input specifies %s interpolation "
+ "qualifier\n",
+ producer_stage,
+ output->name,
+ output->interpolation_string(),
+ consumer_stage,
+ input->interpolation_string());
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
+
void
link_shaders(struct glsl_program *prog)
{
@@ -285,8 +379,18 @@
num_shader_executables++;
}
- if (cross_validate_uniforms(shader_executables, num_shader_executables))
+ if (cross_validate_uniforms(shader_executables, num_shader_executables)) {
+ /* Validate the inputs of each stage with the output of the preceeding
+ * stage.
+ */
+ for (unsigned i = 1; i < num_shader_executables; i++) {
+ if (!cross_validate_outputs_to_inputs(shader_executables[i - 1],
+ shader_executables[i]))
+ goto done;
+ }
+
prog->LinkStatus = true;
+ }
done:
free(vert_shader_list);