glsl: Trim the size of uniform arrays to the maximum element used.

Fixes glsl-getactiveuniform-array-size.

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index b60bb2f0a0a3abb41878c12d84137ef8af1e6bcc..8e4c3299aa68758756a66f8137bf704d98aad59d 100644 (file)
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -1258,6 +1258,11 @@ ast_expression::hir(exec_list *instructions,
         }
       } else if (array->type->array_size() == 0) {
         _mesa_glsl_error(&loc, state, "unsized array index must be constant");
+      } else {
+        if (array->type->is_array()) {
+           ir_variable *v = array->whole_variable_referenced();
+           v->max_array_access = array->type->array_size();
+        }
       }
 
       if (error_emitted)

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 2dc569777e773281b0e3d6f10d242e327eeb0089..deb30d7fecf9534a787983e0e48801e777bb3307 100644 (file)
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -809,6 +809,56 @@ struct uniform_node {
    unsigned slots;
 };
 
+/**
+ * Update the sizes of linked shader uniform arrays to the maximum
+ * array index used.
+ *
+ * From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec:
+ *
+ *     If one or more elements of an array are active,
+ *     GetActiveUniform will return the name of the array in name,
+ *     subject to the restrictions listed above. The type of the array
+ *     is returned in type. The size parameter contains the highest
+ *     array element index used, plus one. The compiler or linker
+ *     determines the highest index used.  There will be only one
+ *     active uniform reported by the GL per uniform array.
+
+ */
+static void
+update_uniform_array_sizes(struct gl_shader_program *prog)
+{
+   for (unsigned i = 0; i < prog->_NumLinkedShaders; i++) {
+      foreach_list(node, prog->_LinkedShaders[i]->ir) {
+        ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+        if ((var == NULL) || (var->mode != ir_var_uniform) ||
+            !var->type->is_array())
+           continue;
+
+        unsigned int size = var->max_array_access;
+        for (unsigned j = 0; j < prog->_NumLinkedShaders; j++) {
+           foreach_list(node2, prog->_LinkedShaders[j]->ir) {
+              ir_variable *other_var = ((ir_instruction *) node2)->as_variable();
+              if (!other_var)
+                 continue;
+
+              if (strcmp(var->name, other_var->name) == 0 &&
+                  other_var->max_array_access > size) {
+                 size = other_var->max_array_access;
+              }
+           }
+        }
+        if (size + 1 != var->type->fields.array->length) {
+           var->type = glsl_type::get_array_instance(var->type->fields.array,
+                                                     size + 1);
+           /* FINISHME: We should update the types of array
+            * dereferences of this variable now.
+            */
+        }
+      }
+   }
+}
+
 void
 assign_uniform_locations(struct gl_shader_program *prog)
 {
@@ -818,6 +868,8 @@ assign_uniform_locations(struct gl_shader_program *prog)
    hash_table *ht = hash_table_ctor(32, hash_table_string_hash,
                                    hash_table_string_compare);
 
+   update_uniform_array_sizes(prog);
+
    for (unsigned i = 0; i < prog->_NumLinkedShaders; i++) {
       unsigned next_position = 0;