Disable Warning 4702 for the PGO builds.

There's more optimization done on a PGO build than on a regular one, this results in some "Unreachable code" warnings that we don't see normally.

But probably anything that this would catch that wouldn't be caught in a normal build isn't going to actually be a bug, so the incremental value of C4702 for PGO builds is likely very small and blocks the setup of the PGO bots.

BUG=380175

Review URL: https://codereview.chromium.org/315323002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276737 0039d316-1c4b-4281-b951-d872f2087c98

base/logging.cc

@@ -537,19 +537,10 @@ LogMessage::LogMessage(const char* file, int line)
   Init(file, line);
 }
 
-#if defined(OS_WIN)
-// Disable warning C4702 ("unreachable code") until we fix crbug.com/380175.
-// TODO(scottmg|sebmarchand): Remove this pragma once the bug is fixed.
-#pragma warning(push)
-#pragma warning(disable: 4702)
-#endif
 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
     : severity_(severity), file_(file), line_(line) {
   Init(file, line);
 }
-#if defined(OS_WIN)
-#pragma warning(pop)
-#endif
 
 LogMessage::LogMessage(const char* file, int line, std::string* result)
     : severity_(LOG_FATAL), file_(file), line_(line) {

build/common.gypi

@@ -4979,6 +4979,14 @@
                   },
                 ],
                 ['optimize=="max"', {
+                    # Disable Warning 4702 ("Unreachable code") for the WPO/PGO
+                    # builds. Probably anything that this would catch that
+                    # wouldn't be caught in a normal build isn't going to
+                    # actually be a bug, so the incremental value of C4702 for
+                    # PGO builds is likely very small.
+                    'msvs_disabled_warnings': [
+                      4702
+                    ],
                     'msvs_settings': {
                       'VCCLCompilerTool': {
                         # 2, optimizeMaxSpeed, Maximize Speed (/O2)

build/config/compiler/BUILD.gn

@@ -766,6 +766,11 @@ config("optimize_max") {
     cflags += [
       "/Ot",   # Favor speed over size.
       "/GL",   # Whole program optimization.
+      # Disable Warning 4702 ("Unreachable code") for the WPO/PGO builds.
+      # Probably anything that this would catch that wouldn't be caught in a
+      # normal build isn't going to actually be a bug, so the incremental value
+      # of C4702 for PGO builds is likely very small.
+      "/wd4702",
     ]
   } else {
     cflags += [