[Mesa-dev] [PATCH v2 2/3] mesa: validate program usage in a pipeline

[Tapani Pälli]

Validation checks that we do not have active shader stages that are not
used by the pipeline.

This fixes a subtest in following CTS test:
	ES31-CTS.sepshaderobjs.StateInteraction

v2: move as generic validation check for both ES and desktop (Timothy)

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
---
 src/mesa/main/context.c     |  9 +++++++++
 src/mesa/main/pipelineobj.c | 35 +++++++++++++++++++++++++++++++++++
 src/mesa/main/pipelineobj.h |  2 ++
 3 files changed, 46 insertions(+)

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index be983d4..d73c984 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -2042,6 +2042,15 @@ _mesa_valid_to_render(struct gl_context *ctx, const char *where)
       }
    }
 
+   /* If SSO in use, validate that all linked program stages are used. */
+   if (ctx->Pipeline.Current) {
+      if (!_mesa_active_program_stages_used(ctx->Pipeline.Current)) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "Shader program active for shader stages that "
+                     "are not used by the pipeline");
+      }
+   }
+
    /* If a program is active and SSO not in use, check if validation of
     * samplers succeeded for the active program. */
    if (ctx->_Shader->ActiveProgram && ctx->_Shader != ctx->Pipeline.Current) {
diff --git a/src/mesa/main/pipelineobj.c b/src/mesa/main/pipelineobj.c
index f4ce3ed..9067551 100644
--- a/src/mesa/main/pipelineobj.c
+++ b/src/mesa/main/pipelineobj.c
@@ -782,6 +782,21 @@ program_stages_interleaved_illegally(const struct gl_pipeline_object *pipe)
    return false;
 }
 
+bool
+_mesa_active_program_stages_used(struct gl_pipeline_object *pipe)
+{
+   unsigned i;
+   for (i = 0; i < MESA_SHADER_STAGES; i++) {
+      if (!pipe->CurrentProgram[i])
+         continue;
+      /* If program has linked but not used by pipeline. */
+      if (pipe->CurrentProgram[i]->LinkStatus &&
+          !pipe->CurrentProgram[i]->ValidProgramUse)
+         return false;
+   }
+   return true;
+}
+
 extern GLboolean
 _mesa_validate_program_pipeline(struct gl_context* ctx,
                                 struct gl_pipeline_object *pipe)
@@ -839,6 +854,26 @@ _mesa_validate_program_pipeline(struct gl_context* ctx,
       return GL_FALSE;
    }
 
+   /* Section 11.1.3.11 (Validation) of the OpenGL 4.5 and OpenGL ES 3.1
+    * spec say:
+    *
+    *     "An INVALID_OPERATION error is generated by any command that trans-
+    *     fers vertices to the GL or launches compute work if the current set
+    *     of active program objects cannot be executed, for reasons including:
+    *
+    *     ...
+    *
+    *     "A program object is active for at least one, but not all of
+    *     the shader stages that were present when the program was linked."
+    */
+   if (!_mesa_active_program_stages_used(pipe)) {
+      pipe->InfoLog =
+         ralloc_strdup(pipe,
+                       "Shader program active for shader stages that "
+                       "are not used by the pipeline");
+      return GL_FALSE;
+   }
+
    /* Section 2.11.11 (Shader Execution), subheading "Validation," of the
     * OpenGL 4.1 spec says:
     *
diff --git a/src/mesa/main/pipelineobj.h b/src/mesa/main/pipelineobj.h
index fbcb765..e56b522 100644
--- a/src/mesa/main/pipelineobj.h
+++ b/src/mesa/main/pipelineobj.h
@@ -70,6 +70,8 @@ extern GLboolean
 _mesa_validate_program_pipeline(struct gl_context * ctx,
                                 struct gl_pipeline_object *pipe);
 
+extern bool
+_mesa_active_program_stages_used(struct gl_pipeline_object *pipe);
 
 extern void GLAPIENTRY
 _mesa_UseProgramStages(GLuint pipeline, GLbitfield stages, GLuint program);
-- 
2.5.0