r302468 - [Driver] Don't enable -fsanitize-use-after-scope when ASan is disabled

[Vedant Kumar via cfe-commits]

Author: vedantk
Date: Mon May  8 16:11:55 2017
New Revision: 302468

URL: http://llvm.org/viewvc/llvm-project?rev=302468&view=rev
Log:
[Driver] Don't enable -fsanitize-use-after-scope when ASan is disabled

When enabling any sanitizer, -fsanitize-use-after-scope is enabled by
default. This doesn't actually turn ASan on, because we've been getting
lucky and there are extra checks in BackendUtil that stop this from
happening.

However, this has been causing a behavior change: extra lifetime markers
are emitted in some cases where they aren't needed or expected.

Modified:
    cfe/trunk/lib/Driver/SanitizerArgs.cpp
    cfe/trunk/test/Driver/fsanitize.c

Modified: cfe/trunk/lib/Driver/SanitizerArgs.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/SanitizerArgs.cpp?rev=302468&r1=302467&r2=302468&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/SanitizerArgs.cpp (original)
+++ cfe/trunk/lib/Driver/SanitizerArgs.cpp Mon May  8 16:11:55 2017
@@ -563,12 +563,11 @@ SanitizerArgs::SanitizerArgs(const ToolC
       }
     }
 
-    if (Arg *A = Args.getLastArg(
-            options::OPT_fsanitize_address_use_after_scope,
-            options::OPT_fno_sanitize_address_use_after_scope)) {
-      AsanUseAfterScope = A->getOption().getID() ==
-                          options::OPT_fsanitize_address_use_after_scope;
-    }
+    AsanUseAfterScope = Args.hasFlag(
+        options::OPT_fsanitize_address_use_after_scope,
+        options::OPT_fno_sanitize_address_use_after_scope, AsanUseAfterScope);
+  } else {
+    AsanUseAfterScope = false;
   }
 
   // Parse -link-cxx-sanitizer flag.

Modified: cfe/trunk/test/Driver/fsanitize.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/fsanitize.c?rev=302468&r1=302467&r2=302468&view=diff
==============================================================================
--- cfe/trunk/test/Driver/fsanitize.c (original)
+++ cfe/trunk/test/Driver/fsanitize.c Mon May  8 16:11:55 2017
@@ -30,7 +30,7 @@
 // RUN: %clang -target x86_64-pc-win32 -fsanitize-coverage=bb %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-COVERAGE-WIN64
 // CHECK-COVERAGE-WIN64: "--dependent-lib={{[^"]*}}ubsan_standalone-x86_64.lib"
 
-// RUN: %clang -target x86_64-linux-gnu -fsanitize=integer %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-INTEGER
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=integer %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-INTEGER -implicit-check-not="-fsanitize-address-use-after-scope"
 // CHECK-INTEGER: "-fsanitize={{((signed-integer-overflow|unsigned-integer-overflow|integer-divide-by-zero|shift-base|shift-exponent),?){5}"}}
 
 // RUN: %clang -fsanitize=bounds -### -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix=CHECK-BOUNDS