[Driver] Add -fno-sanitize-address-globals-dead-stripping

[MaskRay]

Summary

It's customary for these options to have the -fno- form which is sometimes
handy to work around issues. Using the supported driver option is preferred over
the internal cl::opt option -mllvm -asan-globals-live-support=0

[kstoimenov]

LGTM. But please wait for LTGM from vitalybuka@. Also there is internal asan-globals-live-support flag if you need it before this one lands.

clang/include/clang/Driver/Options.td

: Joined<["-"], "fsanitize-address-use-after-return=">,
     NormalizedValuesScope<"llvm::AsanDetectStackUseAfterReturnMode">,
     NormalizedValues<["Never", "Runtime", "Always"]>,
     MarshallingInfoEnum<CodeGenOpts<"SanitizeAddressUseAfterReturn">, "Runtime">;
 defm sanitize_address_poison_custom_array_cookie : BoolOption<"f", "sanitize-address-poison-custom-array-cookie",
   CodeGenOpts<"SanitizeAddressPoisonCustomArrayCookie">, DefaultFalse,
   PosFlag<SetTrue, [], "Enable">, NegFlag<SetFalse, [], "Disable">,
   BothFlags<[], " poisoning array cookies when using custom operator new[] in AddressSanitizer">>,
   Group<f_clang_Group>;
-def fsanitize_address_globals_dead_stripping : Flag<["-"], "fsanitize-address-globals-dead-stripping">,
-  Group<f_clang_Group>, HelpText<"Enable linker dead stripping of globals in AddressSanitizer">,
-  MarshallingInfoFlag<CodeGenOpts<"SanitizeAddressGlobalsDeadStripping">, "false">;
+defm sanitize_address_globals_dead_stripping : BoolOption<"f", "sanitize-address-globals-dead-stripping",
+  CodeGenOpts<"SanitizeAddressGlobalsDeadStripping">, DefaultFalse,
+  PosFlag<SetTrue, [], "Enable linker dead stripping of globals in AddressSanitizer">,
+  NegFlag<SetFalse, [], "Disable linker dead stripping of globals in AddressSanitizer">>,
+  Group<f_clang_Group>;
 defm sanitize_address_use_odr_indicator : BoolOption<"f", "sanitize-address-use-odr-indicator",
   CodeGenOpts<"SanitizeAddressUseOdrIndicator">, DefaultFalse,
   PosFlag<SetTrue, [], "Enable ODR indicator globals to avoid false ODR violation"
             " reports in partially sanitized programs at the cost of an increase in binary size">,
   NegFlag<SetFalse, [], "Disable ODR indicator globals">>,
   Group<f_clang_Group>;
 def sanitize_address_destructor_EQ
     : Joined<["-"], "fsanitize-address-destructor=">,

clang/lib/Driver/SanitizerArgs.cpp

if (AllAddedKinds & SanitizerKind::Address) {
     AsanOutlineInstrumentation =
         Args.hasFlag(options::OPT_fsanitize_address_outline_instrumentation,
                      options::OPT_fno_sanitize_address_outline_instrumentation,
                      AsanOutlineInstrumentation);
 
     // As a workaround for a bug in gold 2.26 and earlier, dead stripping of
     // globals in ASan is disabled by default on ELF targets.
     // See https://sourceware.org/bugzilla/show_bug.cgi?id=19002
-    AsanGlobalsDeadStripping =
+    AsanGlobalsDeadStripping = Args.hasFlag(
+        options::OPT_fsanitize_address_globals_dead_stripping,
+        options::OPT_fno_sanitize_address_globals_dead_stripping,
         !TC.getTriple().isOSBinFormatELF() || TC.getTriple().isOSFuchsia() ||
-        TC.getTriple().isPS4() ||
-        Args.hasArg(options::OPT_fsanitize_address_globals_dead_stripping);
+            TC.getTriple().isPS4());
 
     AsanUseOdrIndicator =
         Args.hasFlag(options::OPT_fsanitize_address_use_odr_indicator,
                      options::OPT_fno_sanitize_address_use_odr_indicator,
                      AsanUseOdrIndicator);
 
     if (AllAddedKinds & SanitizerKind::PointerCompare & ~AllRemove) {
       AsanInvalidPointerCmp = true;

clang/test/Driver/fsanitize.c

 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address -fsanitize-address-poison-custom-array-cookie -fno-sanitize-address-poison-custom-array-cookie %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-POISON-CUSTOM-ARRAY-NEW-COOKIE-BOTH-OFF
 // CHECK-POISON-CUSTOM-ARRAY-NEW-COOKIE-BOTH-OFF-NOT: -cc1{{.*}}address-poison-custom-array-cookie
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-WITHOUT-POISON-CUSTOM-ARRAY-NEW-COOKIE
 // CHECK-ASAN-WITHOUT-POISON-CUSTOM-ARRAY-NEW-COOKIE-NOT: -cc1{{.*}}address-poison-custom-array-cookie
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address -fsanitize-address-globals-dead-stripping %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-GLOBALS
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-ASAN-GLOBALS
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-sanitize-address-globals-dead-stripping %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-ASAN-GLOBALS
 // RUN: %clang_cl --target=x86_64-windows-msvc -fsanitize=address -fsanitize-address-globals-dead-stripping -### -- %s 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-GLOBALS
 // RUN: %clang_cl --target=x86_64-windows-msvc -fsanitize=address -### -- %s 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-GLOBALS
 // RUN: %clang -target x86_64-scei-ps4  -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-GLOBALS
 // CHECK-ASAN-GLOBALS: -cc1{{.*}}-fsanitize-address-globals-dead-stripping
 // CHECK-NO-ASAN-GLOBALS-NOT: -cc1{{.*}}-fsanitize-address-globals-dead-stripping
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize-address-outline-instrumentation %s -### 2>&1 | \
 // RUN:     FileCheck %s --check-prefix=CHECK-ASAN-OUTLINE-WARN