diff options
Diffstat (limited to 'gcc-4.7/gcc/cfgexpand.c')
| -rw-r--r-- | gcc-4.7/gcc/cfgexpand.c | 58 |
1 files changed, 53 insertions, 5 deletions
diff --git a/gcc-4.7/gcc/cfgexpand.c b/gcc-4.7/gcc/cfgexpand.c index bde15f696..53066e031 100644 --- a/gcc-4.7/gcc/cfgexpand.c +++ b/gcc-4.7/gcc/cfgexpand.c @@ -1508,15 +1508,39 @@ estimated_stack_frame_size (struct cgraph_node *node) return size; } +/* Helper routine to check if a record or union contains an array field. */ + +static int +record_or_union_type_has_array_p (const_tree tree_type) +{ + tree fields = TYPE_FIELDS (tree_type); + tree f; + + for (f = fields; f; f = DECL_CHAIN (f)) + { + if (TREE_CODE (f) == FIELD_DECL) + { + tree field_type = TREE_TYPE (f); + if (RECORD_OR_UNION_TYPE_P (field_type)) + return record_or_union_type_has_array_p (field_type); + if (TREE_CODE (field_type) == ARRAY_TYPE) + return 1; + } + } + return 0; +} + /* Expand all variables used in the function. */ static void expand_used_vars (void) { tree var, outer_block = DECL_INITIAL (current_function_decl); + referenced_var_iterator rvi; VEC(tree,heap) *maybe_local_decls = NULL; unsigned i; unsigned len; + int gen_stack_protect_signal = 0; /* Compute the phase of the stack frame for this function. */ { @@ -1549,6 +1573,23 @@ expand_used_vars (void) } } + FOR_EACH_REFERENCED_VAR (cfun, var, rvi) + if (!is_global_var (var)) + { + tree var_type = TREE_TYPE (var); + /* Examine local referenced variables that have their addresses taken, + contain an array, or are arrays. */ + if (TREE_CODE (var) == VAR_DECL + && (TREE_CODE (var_type) == ARRAY_TYPE + || TREE_ADDRESSABLE (var) + || (RECORD_OR_UNION_TYPE_P (var_type) + && record_or_union_type_has_array_p (var_type)))) + { + ++gen_stack_protect_signal; + break; + } + } + /* At this point all variables on the local_decls with TREE_USED set are not associated with any block scope. Lay them out. */ @@ -1639,11 +1680,18 @@ expand_used_vars (void) dump_stack_var_partition (); } - /* There are several conditions under which we should create a - stack guard: protect-all, alloca used, protected decls present. */ - if (flag_stack_protect == 2 - || (flag_stack_protect - && (cfun->calls_alloca || has_protected_decls))) + /* Create stack guard, if + a) "-fstack-protector-all" - always; + b) "-fstack-protector-strong" - if there are arrays, memory + references to local variables, alloca used, or protected decls present; + c) "-fstack-protector" - if alloca used, or protected decls present */ + if (flag_stack_protect == 3 /* -fstack-protector-all */ + || (flag_stack_protect == 2 /* -fstack-protector-strong */ + && (gen_stack_protect_signal || cfun->calls_alloca + || has_protected_decls)) + || (flag_stack_protect == 1 /* -fstack-protector */ + && (cfun->calls_alloca + || has_protected_decls))) create_stack_guard (); /* Assign rtl to each variable based on these partitions. */ |