From a7017746d77f33cb60af20c9fcefeb0e6ac89fd4 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Wed, 13 Sep 2017 09:08:01 +0200 Subject: [PATCH] glsl: make the redeclared variable NULL if it is deleted MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit get_variable_being_redeclared() can delete the original variable in a specific scenario. The code sets it to NULL after this so other code in that same function doesn't try to access trashed memory after the fact, however, the copy of that variable in the caller code won't see any of this making it very easy to overlook. Make the function a bit safer by taking a pointer to the original variable so we can also make NULL the caller's pointer to the variable if this function deletes it. Reviewed-by: Nicolai Hähnle --- src/compiler/glsl/ast_to_hir.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp index 6dd0f1d..5600e14 100644 --- a/src/compiler/glsl/ast_to_hir.cpp +++ b/src/compiler/glsl/ast_to_hir.cpp @@ -4166,11 +4166,13 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual, * otherwise. */ static ir_variable * -get_variable_being_redeclared(ir_variable *var, YYLTYPE loc, +get_variable_being_redeclared(ir_variable **var_ptr, YYLTYPE loc, struct _mesa_glsl_parse_state *state, bool allow_all_redeclarations, bool *is_redeclaration) { + ir_variable *var = *var_ptr; + /* Check if this declaration is actually a re-declaration, either to * resize an array or add qualifiers to an existing variable. * @@ -4211,6 +4213,7 @@ get_variable_being_redeclared(ir_variable *var, YYLTYPE loc, earlier->type = var->type; delete var; var = NULL; + *var_ptr = NULL; } else if ((state->ARB_fragment_coord_conventions_enable || state->is_version(150, 0)) && strcmp(var->name, "gl_FragCoord") == 0 @@ -5457,7 +5460,7 @@ ast_declarator_list::hir(exec_list *instructions, bool is_redeclaration; ir_variable *declared_var = - get_variable_being_redeclared(var, decl->get_location(), state, + get_variable_being_redeclared(&var, decl->get_location(), state, false /* allow_all_redeclarations */, &is_redeclaration); if (is_redeclaration) { @@ -8215,7 +8218,7 @@ ast_interface_block::hir(exec_list *instructions, if (redeclaring_per_vertex) { bool is_redeclaration; ir_variable *declared_var = - get_variable_being_redeclared(var, loc, state, + get_variable_being_redeclared(&var, loc, state, true /* allow_all_redeclarations */, &is_redeclaration); if (!var_is_gl_id || !is_redeclaration) { -- 2.7.4