[Mesa-dev] [PATCH] glsl: First argument to atomic functions must be a buffer variable

[Iago Toral Quiroga]

v2:
  - Add ssbo_in the names of the static functions so it is clear that this
    is specific to SSBO atomics.

v3:
  - Move the check after the loop (Kristian Høgsberg)
---
 src/glsl/ast_function.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp
index ff5ecb9..26d4c62 100644
--- a/src/glsl/ast_function.cpp
+++ b/src/glsl/ast_function.cpp
@@ -142,6 +142,31 @@ verify_image_parameter(YYLTYPE *loc, _mesa_glsl_parse_state *state,
    return true;
 }
 
+static bool
+verify_first_atomic_ssbo_parameter(YYLTYPE *loc, _mesa_glsl_parse_state *state,
+                                   ir_variable *var)
+{
+   if (!var || !var->is_in_shader_storage_block()) {
+      _mesa_glsl_error(loc, state, "First argument to atomic function "
+                       "must be a buffer variable");
+      return false;
+   }
+   return true;
+}
+
+static bool
+is_atomic_ssbo_function(const char *func_name)
+{
+   return !strcmp(func_name, "atomicAdd") ||
+          !strcmp(func_name, "atomicMin") ||
+          !strcmp(func_name, "atomicMax") ||
+          !strcmp(func_name, "atomicAnd") ||
+          !strcmp(func_name, "atomicOr") ||
+          !strcmp(func_name, "atomicXor") ||
+          !strcmp(func_name, "atomicExchange") ||
+          !strcmp(func_name, "atomicCompSwap");
+}
+
 /**
  * Verify that 'out' and 'inout' actual parameters are lvalues.  Also, verify
  * that 'const_in' formal parameters (an extension in our IR) correspond to
@@ -256,6 +281,23 @@ verify_parameter_modes(_mesa_glsl_parse_state *state,
       actual_ir_node  = actual_ir_node->next;
       actual_ast_node = actual_ast_node->next;
    }
+
+   /* The first parameter of atomic functions must be a buffer variable */
+   const char *func_name = sig->function_name();
+   bool is_atomic_ssbo = is_atomic_ssbo_function(func_name);
+   if (is_atomic_ssbo) {
+      const ir_rvalue *const actual = (ir_rvalue *) actual_ir_parameters.head;
+
+      const ast_expression *const actual_ast =
+         exec_node_data(ast_expression, actual_ast_parameters.head, link);
+      YYLTYPE loc = actual_ast->get_location();
+
+      if (!verify_first_atomic_ssbo_parameter(&loc, state,
+                                              actual->variable_referenced())) {
+         return false;
+      }
+   }
+
    return true;
 }
 
-- 
1.9.1