[Mesa-dev] [PATCH 20/23] glsl/linker: Count and check image resources.

[Francisco Jerez]

---
 src/glsl/link_uniforms.cpp | 13 +++++++++++-
 src/glsl/linker.cpp        | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
index 0a15739..c75a38c 100644
--- a/src/glsl/link_uniforms.cpp
+++ b/src/glsl/link_uniforms.cpp
@@ -240,7 +240,8 @@ class count_uniform_size : public program_resource_visitor {
 public:
    count_uniform_size(struct string_to_uint_map *map)
       : num_active_uniforms(0), num_values(0), num_shader_samplers(0),
-	num_shader_uniform_components(0), is_ubo_var(false), map(map)
+        num_shader_images(0), num_shader_uniform_components(0),
+        is_ubo_var(false), map(map)
    {
       /* empty */
    }
@@ -248,6 +249,7 @@ public:
    void start_shader()
    {
       this->num_shader_samplers = 0;
+      this->num_shader_images = 0;
       this->num_shader_uniform_components = 0;
    }
 
@@ -277,6 +279,11 @@ public:
    unsigned num_shader_samplers;
 
    /**
+    * Number of images used
+    */
+   unsigned num_shader_images;
+
+   /**
     * Number of uniforms used in the current shader
     */
    unsigned num_shader_uniform_components;
@@ -303,6 +310,9 @@ private:
       if (type->contains_sampler()) {
 	 this->num_shader_samplers +=
 	    type->is_array() ? type->array_size() : 1;
+      } else if (type->contains_image()) {
+         this->num_shader_images += values;
+         this->num_shader_uniform_components += values;
       } else {
 	 /* Accumulate the total number of uniform slots used by this shader.
 	  * Note that samplers do not count against this limit because they
@@ -782,6 +792,7 @@ link_assign_uniform_locations(struct gl_shader_program *prog)
       }
 
       sh->num_samplers = uniform_size.num_shader_samplers;
+      sh->NumImages = uniform_size.num_shader_images;
       sh->num_uniform_components = uniform_size.num_shader_uniform_components;
 
       sh->num_combined_uniform_components = sh->num_uniform_components;
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index fac186a..86a0cae 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -1980,6 +1980,55 @@ check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
    }
 }
 
+/**
+ * Validate shader image resources.
+ */
+static void
+check_image_resources(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+   STATIC_ASSERT(MESA_SHADER_TYPES == 3);
+   static const char *const shader_names[MESA_SHADER_TYPES] = {
+      "vertex", "geometry", "fragment"
+   };
+   const unsigned max_images[MESA_SHADER_TYPES] = {
+      ctx->Const.VertexProgram.MaxImageUniforms,
+      ctx->Const.GeometryProgram.MaxImageUniforms,
+      ctx->Const.FragmentProgram.MaxImageUniforms
+   };
+   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_TYPES; i++) {
+      struct gl_shader *sh = prog->_LinkedShaders[i];
+
+      if (sh) {
+         if (sh->NumImages > max_images[i])
+            linker_error(prog, "Too many %s shader image uniforms",
+                         shader_names[i]);
+
+         total_image_units += sh->NumImages;
+
+         if (i == MESA_SHADER_FRAGMENT) {
+            foreach_list(node, sh->ir) {
+               ir_variable *var = ((ir_instruction *)node)->as_variable();
+               if (var && var->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");
+}
+
 void
 link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 {
@@ -2367,6 +2416,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    store_fragdepth_layout(prog);
 
    check_resources(ctx, prog);
+   check_image_resources(ctx, prog);
    link_check_atomic_counter_resources(ctx, prog);
 
    if (!prog->LinkStatus)
-- 
1.8.3.4