brettw2

build/config/sanitizers/sanitizers.gni

Index: build/config/sanitizers/sanitizers.gni
diff --git a/build/config/sanitizers/sanitizers.gni b/build/config/sanitizers/sanitizers.gni
index 40ffb94d09885f6b6ed056860db472e0bc186bfe..931139248ae5fbf1863b93f18c8a164924f4877f 100644
--- a/build/config/sanitizers/sanitizers.gni
+++ b/build/config/sanitizers/sanitizers.gni
@@ -2,144 +2,148 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-declare_args() {
-  # Compile for Address Sanitizer to find memory bugs.
+if (current_toolchain == default_toolchain) {
+  declare_args() {
+    # Compile for Address Sanitizer to find memory bugs.
+    is_asan = false
+
+    # Compile for Leak Sanitizer to find leaks.
+    is_lsan = false
+
+    # Compile for Memory Sanitizer to find uninitialized reads.
+    is_msan = false
+
+    # Compile for Thread Sanitizer to find threading bugs.
+    is_tsan = false
+
+    # Compile for Undefined Behaviour Sanitizer to find various types of
+    # undefined behaviour (excludes vptr checks).
+    is_ubsan = false
+
+    # Halt the program if a problem is detected.
+    is_ubsan_no_recover = false
+
+    # Compile for Undefined Behaviour Sanitizer's null pointer checks.
+    is_ubsan_null = false
+
+    # Compile for Undefined Behaviour Sanitizer's vptr checks.
+    is_ubsan_vptr = false
+
+    # Track where uninitialized memory originates from. From fastest to slowest:
+    # 0 - no tracking, 1 - track only the initial allocation site, 2 - track the
+    # chain of stores leading from allocation site to use site.
+    msan_track_origins = 2
+
+    # Use dynamic libraries instrumented by one of the sanitizers instead of the
+    # standard system libraries. Set this flag to download prebuilt binaries
+    # from GCS.
+    use_prebuilt_instrumented_libraries = false
+
+    # Use dynamic libraries instrumented by one of the sanitizers instead of the
+    # standard system libraries. Set this flag to build the libraries from
+    # source.
+    use_locally_built_instrumented_libraries = false
+
+    # Enable building with SyzyAsan which can find certain types of memory
+    # errors. Only works on Windows. See
+    # https://github.com/google/syzygy/wiki/SyzyASanHowTo
+    is_syzyasan = false
+
+    # Compile with Control Flow Integrity to protect virtual calls and casts.
+    # See http://clang.llvm.org/docs/ControlFlowIntegrity.html
+    #
+    # TODO(pcc): Remove this flag if/when CFI is enabled in official builds.
+    is_cfi = false
+
+    # Enable checks for bad casts: derived cast and unrelated cast.
+    # TODO(krasin): remove this when we're ready to add these checks by default.
+    # https://crbug.com/626794
+    use_cfi_cast = false
+
+    # By default, Control Flow Integrity will crash the program if it detects a
+    # violation. Set this to true to print detailed diagnostics instead.
+    use_cfi_diag = false
+
+    # Compile for fuzzing with LLVM LibFuzzer.
+    # See http://www.chromium.org/developers/testing/libfuzzer
+    use_libfuzzer = false
+
+    # Compile for fuzzing with AFL.
+    use_afl = false
+
+    # Enables core ubsan security features. Will later be removed once it
+    # matches is_ubsan.
+    is_ubsan_security = false
+
+    # Compile for fuzzing with Dr. Fuzz
+    # See http://www.chromium.org/developers/testing/dr-fuzz
+    use_drfuzz = false
+
+    # Helper variable for testing builds with disabled libfuzzer.
+    # Not for client use.
+    disable_libfuzzer = false
+
+    # Value for -fsanitize-coverage flag. Setting this causes
+    # use_sanitizer_coverage to be enabled.
+    # Default value when unset and use_afl=true:
+    # trace-pc
+    # Default value when unset and use_sanitizer_coverage=true:
+    #     edge,indirect-calls,8bit-counters
+    sanitizer_coverage_flags = ""
+  }
+
+  # Args that are in turn dependent on other args must be in a separate
+  # declare_args block. User overrides are only applied at the end of a
+  # declare_args block.
+  declare_args() {
+    # Use libc++ (buildtools/third_party/libc++ and
+    # buildtools/third_party/libc++abi) instead of stdlibc++ as standard
+    # library.  This is intended to be used for instrumented builds.
+    use_custom_libcxx =
+        (is_asan && is_linux && !is_chromeos) || is_tsan || is_msan ||
+        is_ubsan || is_ubsan_security || use_libfuzzer || use_afl
+
+    # Enable -fsanitize-coverage.
+    use_sanitizer_coverage =
+        use_libfuzzer || use_afl || sanitizer_coverage_flags != ""
+
+    # Detect overflow/underflow for global objects.
+    #
+    # Android build relies on -Wl,--gc-sections removing unreachable code.
+    # ASan instrumentation for globals inhibits this and results in a
+    # library with unresolvable relocations.
+    # TODO(eugenis): find a way to reenable this.
+    #
+    # Mac: http://crbug.com/352073
+    asan_globals = !is_android && !is_mac
+  }
+} else {
+  # Disable sanitizers for non-default toolchains.
   is_asan = false
-
-  # Compile for Leak Sanitizer to find leaks.
   is_lsan = false
-
-  # Compile for Memory Sanitizer to find uninitialized reads.
   is_msan = false
-
-  # Compile for Thread Sanitizer to find threading bugs.
+  is_syzyasan = false
   is_tsan = false
-
-  # Compile for Undefined Behaviour Sanitizer to find various types of
-  # undefined behaviour (excludes vptr checks).
   is_ubsan = false
-
-  # Halt the program if a problem is detected.
   is_ubsan_no_recover = false
-
-  # Compile for Undefined Behaviour Sanitizer's null pointer checks.
   is_ubsan_null = false
-
-  # Compile for Undefined Behaviour Sanitizer's vptr checks.
   is_ubsan_vptr = false
-
-  # Track where uninitialized memory originates from. From fastest to slowest:
-  # 0 - no tracking, 1 - track only the initial allocation site, 2 - track the
-  # chain of stores leading from allocation site to use site.
-  msan_track_origins = 2
-
-  # Use dynamic libraries instrumented by one of the sanitizers instead of the
-  # standard system libraries. Set this flag to download prebuilt binaries from
-  # GCS.
+  msan_track_origins = 0
   use_prebuilt_instrumented_libraries = false
-
-  # Use dynamic libraries instrumented by one of the sanitizers instead of the
-  # standard system libraries. Set this flag to build the libraries from source.
   use_locally_built_instrumented_libraries = false
-
-  # Enable building with SyzyAsan which can find certain types of memory
-  # errors. Only works on Windows. See
-  # https://github.com/google/syzygy/wiki/SyzyASanHowTo
-  is_syzyasan = false
-
-  # Compile with Control Flow Integrity to protect virtual calls and casts.
-  # See http://clang.llvm.org/docs/ControlFlowIntegrity.html
-  #
-  # TODO(pcc): Remove this flag if/when CFI is enabled in official builds.
   is_cfi = false
-
-  # Enable checks for bad casts: derived cast and unrelated cast.
-  # TODO(krasin): remove this, when we're ready to add these checks by default.
-  # https://crbug.com/626794
   use_cfi_cast = false
-
-  # By default, Control Flow Integrity will crash the program if it detects a
-  # violation. Set this to true to print detailed diagnostics instead.
   use_cfi_diag = false
-
-  # Compile for fuzzing with LLVM LibFuzzer.
-  # See http://www.chromium.org/developers/testing/libfuzzer
   use_libfuzzer = false
-
-  # Compile for fuzzing with AFL.
   use_afl = false
-
-  # Enables core ubsan security features. Will later be removed once it matches
-  # is_ubsan.
   is_ubsan_security = false
-
-  # Compile for fuzzing with Dr. Fuzz
-  # See http://www.chromium.org/developers/testing/dr-fuzz
   use_drfuzz = false
-
-  # Helper variable for testing builds with disabled libfuzzer.
-  # Not for client use.
   disable_libfuzzer = false
-
-  # Value for -fsanitize-coverage flag. Setting this causes
-  # use_sanitizer_coverage to be enabled.
-  # Default value when unset and use_afl=true:
-  # trace-pc
-  # Default value when unset and use_sanitizer_coverage=true:
-  #     edge,indirect-calls,8bit-counters
   sanitizer_coverage_flags = ""
-}
-
-# Disable sanitizers for non-default toolchains.
-if (current_toolchain != default_toolchain) {
-  is_asan = false
-  is_cfi = false
-  is_lsan = false
-  is_msan = false
-  is_syzyasan = false
-  is_tsan = false
-  is_ubsan = false
-  is_ubsan_null = false
-  is_ubsan_no_recover = false
-  is_ubsan_security = false
-  is_ubsan_vptr = false
-  msan_track_origins = 0
-  sanitizer_coverage_flags = ""
-  use_cfi_diag = false
   use_custom_libcxx = false
-  use_drfuzz = false
-  use_libfuzzer = false
-  use_prebuilt_instrumented_libraries = false
-  use_locally_built_instrumented_libraries = false
   use_sanitizer_coverage = false
 }
 
-# Args that are in turn dependent on other args must be in a separate
-# declare_args block. User overrides are only applied at the end of a
-# declare_args block.
-declare_args() {
-  # Use libc++ (buildtools/third_party/libc++ and
-  # buildtools/third_party/libc++abi) instead of stdlibc++ as standard library.
-  # This is intended to be used for instrumented builds.
-  use_custom_libcxx =
-      (is_asan && is_linux && !is_chromeos) || is_tsan || is_msan || is_ubsan ||
-      is_ubsan_security || use_libfuzzer || use_afl
-
-  # Enable -fsanitize-coverage.
-  use_sanitizer_coverage =
-      use_libfuzzer || use_afl || sanitizer_coverage_flags != ""
-
-  # Detect overflow/underflow for global objects.
-  #
-  # Android build relies on -Wl,--gc-sections removing unreachable code.
-  # ASan instrumentation for globals inhibits this and results in a
-  # library with unresolvable relocations.
-  # TODO(eugenis): find a way to reenable this.
-  #
-  # Mac: http://crbug.com/352073
-  asan_globals = !is_android && !is_mac
-}
-
 if (use_afl && sanitizer_coverage_flags == "") {
   sanitizer_coverage_flags = "trace-pc"
 } else if (use_sanitizer_coverage && sanitizer_coverage_flags == "") {