[MSan] Add flag to disable use-after-dtor.

Summary: Flag is -fno-sanitize-use-after-dtor.

Reviewers: vitalybuka, eugenis, kcc

Reviewed By: vitalybuka, eugenis

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D37867

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@313314 91177308-0d34-0410-b5e6-96231b3b80d8

Author: morehouse

include/clang/Driver/Options.td

@@ -851,6 +851,9 @@ def fno_sanitize_memory_track_origins : Flag<["-"], "fno-sanitize-memory-track-o
 def fsanitize_memory_use_after_dtor : Flag<["-"], "fsanitize-memory-use-after-dtor">,
                                      Group<f_clang_Group>,
                                      HelpText<"Enable use-after-destroy detection in MemorySanitizer">;
+def fno_sanitize_memory_use_after_dtor : Flag<["-"], "fno-sanitize-memory-use-after-dtor">,
+                                     Group<f_clang_Group>,
+                                     HelpText<"Disable use-after-destroy detection in MemorySanitizer">;
 def fsanitize_address_field_padding : Joined<["-"], "fsanitize-address-field-padding=">,
                                         Group<f_clang_Group>,
                                         HelpText<"Level of field padding for AddressSanitizer">;

lib/Driver/SanitizerArgs.cpp

@@ -489,7 +489,9 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
       }
     }
     MsanUseAfterDtor =
-        Args.hasArg(options::OPT_fsanitize_memory_use_after_dtor);
+        Args.hasFlag(options::OPT_fsanitize_memory_use_after_dtor,
+                     options::OPT_fno_sanitize_memory_use_after_dtor,
+                     false);
     NeedPIE |= !(TC.getTriple().isOSLinux() &&
                  TC.getTriple().getArch() == llvm::Triple::x86_64);
   }

lib/Frontend/CompilerInvocation.cpp

@@ -830,7 +830,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.SanitizeMemoryTrackOrigins =
       getLastArgIntValue(Args, OPT_fsanitize_memory_track_origins_EQ, 0, Diags);
   Opts.SanitizeMemoryUseAfterDtor =
-      Args.hasArg(OPT_fsanitize_memory_use_after_dtor);
+      Args.hasFlag(OPT_fsanitize_memory_use_after_dtor,
+                   OPT_fno_sanitize_memory_use_after_dtor,
+                   false);
   Opts.SanitizeMinimalRuntime = Args.hasArg(OPT_fsanitize_minimal_runtime);
   Opts.SanitizeCfiCrossDso = Args.hasArg(OPT_fsanitize_cfi_cross_dso);
   Opts.SanitizeStats = Args.hasArg(OPT_fsanitize_stats);

test/Driver/fsanitize.c

@@ -172,8 +172,14 @@
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fsanitize-memory-track-origins=3 -pie %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TRACK-ORIGINS-3
 // CHECK-TRACK-ORIGINS-3: error: invalid value '3' in '-fsanitize-memory-track-origins=3'
 
-// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fsanitize-memory-use-after-dtor -pie %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-MSAN-USE-AFTER-DTOR
-// CHECK-MSAN-USE-AFTER-DTOR: -cc1{{.*}}-fsanitize-memory-use-after-dtor
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fsanitize-memory-use-after-dtor %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-DTOR
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fno-sanitize-memory-use-after-dtor -fsanitize-memory-use-after-dtor %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-DTOR
+// CHECK-USE-AFTER-DTOR: -cc1{{.*}}-fsanitize-memory-use-after-dtor
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fno-sanitize-memory-use-after-dtor %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-DTOR-OFF
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fsanitize-memory-use-after-dtor -fno-sanitize-memory-use-after-dtor %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-DTOR-OFF
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-DTOR-OFF
+// CHECK-USE-AFTER-DTOR-OFF-NOT: -cc1{{.*}}memory-use-after-dtor
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address -fsanitize-address-field-padding=0 %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-FIELD-PADDING-0
 // CHECK-ASAN-FIELD-PADDING-0-NOT: -fsanitize-address-field-padding