Introduce -fsanitize-address-use-after-scope

	* c-warn.c (warn_for_unused_label): Save all labels used
	in goto or in &label.
	* asan.c (enum asan_check_flags): Move the enum to header file.
	(asan_init_shadow_ptr_types): Make type creation more generic.
	(shadow_mem_size): New function.
	(asan_emit_stack_protection): Use newly added ASAN_SHADOW_GRANULARITY.
	Rewritten stack unpoisoning code.
	(build_shadow_mem_access): Add new argument return_address.
	(instrument_derefs): Instrument local variables if use after scope
	sanitization is enabled.
	(asan_store_shadow_bytes): New function.
	(asan_expand_mark_ifn): Likewise.
	(asan_sanitize_stack_p): Moved from asan_sanitize_stack_p.
	* asan.h (enum asan_mark_flags): Moved here from asan.c
	(asan_protect_stack_decl): Protect all declaration that need
	to live in memory.
	(asan_sanitize_use_after_scope): New function.
	(asan_no_sanitize_address_p): Likewise.
	* cfgexpand.c (partition_stack_vars): Consider
	asan_sanitize_use_after_scope in condition.
	(expand_stack_vars): Likewise.
	* common.opt (-fsanitize-address-use-after-scope): New option.
	* doc/invoke.texi (use-after-scope-direct-emission-threshold):
	Explain the parameter.
	* flag-types.h (enum sanitize_code): Define SANITIZE_USE_AFTER_SCOPE.
	* gimplify.c (build_asan_poison_call_expr): New function.
	(asan_poison_variable): Likewise.
	(gimplify_bind_expr): Generate poisoning/unpoisoning for local
	variables that have address taken.
	(gimplify_decl_expr): Likewise.
	(gimplify_target_expr): Likewise for C++ temporaries.
	(sort_by_decl_uid): New function.
	(gimplify_expr): Unpoison all variables for a label we can jump
	from outside of a scope.
	(gimplify_switch_expr): Unpoison variables defined in the switch
	context.
	(gimplify_function_tree): Clear asan_poisoned_variables.
	(asan_poison_variables): New function.
	(warn_switch_unreachable_r): Handle IFN_ASAN_MARK.
	* internal-fn.c (expand_ASAN_MARK): New function.
	* internal-fn.def (ASAN_MARK): Declare.
	* opts.c (finish_options): Handle -fstack-reuse if
	-fsanitize-address-use-after-scope is enabled.
	(common_handle_option): Enable address sanitization if
	-fsanitize-address-use-after-scope is enabled.
	* params.def (PARAM_USE_AFTER_SCOPE_DIRECT_EMISSION_THRESHOLD):
	New parameter.
	* params.h: Likewise.
	* sancov.c (pass_sanopt::execute): Handle IFN_ASAN_MARK.
	* sanitizer.def: Define __asan_poison_stack_memory and
	__asan_unpoison_stack_memory functions.
	* asan.c (asan_mark_poison_p): New function.
	(transform_statements): Handle asan_mark_poison_p calls.
	* gimple.c (nonfreeing_call_p): Handle IFN_ASAN_MARK.

From-SVN: r241896

1 files changed, 4 insertions, 14 deletions

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 430ad38..7ffb558 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -868,18 +868,6 @@ union_stack_vars (size_t a, size_t b)
     }
 }
 
-/* Return true if the current function should have its stack frame
-   protected by address sanitizer.  */
-
-static inline bool
-asan_sanitize_stack_p (void)
-{
-  return ((flag_sanitize & SANITIZE_ADDRESS)
-	  && ASAN_STACK
-	  && !lookup_attribute ("no_sanitize_address",
-				DECL_ATTRIBUTES (current_function_decl)));
-}
-
 /* A subroutine of expand_used_vars.  Binpack the variables into
    partitions constrained by the interference graph.  The overall
    algorithm used is as follows:
@@ -941,7 +929,8 @@ partition_stack_vars (void)
 	     sizes, as the shorter vars wouldn't be adequately protected.
 	     Don't do that for "large" (unsupported) alignment objects,
 	     those aren't protected anyway.  */
-	  if (asan_sanitize_stack_p () && isize != jsize
+	  if ((asan_sanitize_stack_p ())
+	      && isize != jsize
 	      && ialign * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
 	    break;
 
@@ -1128,7 +1117,8 @@ expand_stack_vars (bool (*pred) (size_t), struct stack_vars_data *data)
       if (alignb * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT)
 	{
 	  base = virtual_stack_vars_rtx;
-	  if (asan_sanitize_stack_p () && pred)
+	  if ((asan_sanitize_stack_p ())
+	      && pred)
 	    {
 	      HOST_WIDE_INT prev_offset
 		= align_base (frame_offset,