Enable /analyze in gn builds

build/config/win/BUILD.gn

Index: build/config/win/BUILD.gn
diff --git a/build/config/win/BUILD.gn b/build/config/win/BUILD.gn
index bdbf7eabe809583af7fb0d7ef470bea2cadf1b2d..079e7a32769c13dcecd4c09eb2574addcb5ca2f4 100644
--- a/build/config/win/BUILD.gn
+++ b/build/config/win/BUILD.gn
@@ -8,6 +8,14 @@ import("//build/config/win/visual_studio_version.gni")
 
 assert(is_win)
 
+declare_args() {
+  # Set this to true to enable static analysis through Visual Studio's
+  # /analyze. This dramatically slows compiles and reports thousands of
+  # warnings, so normally this is done on a build machine and only the new
+  # warnings are examined.
+  use_vs_code_analysis = false
+}
+
 # This is included by reference in the //build/config/compiler config that
 # is applied to all targets. It is here to separate out the logic that is
 # Windows-only.
@@ -80,6 +88,46 @@ config("compiler") {
   }
 }
 
+config("vs_code_analysis") {
+  if (use_vs_code_analysis) {
+    # When use_vs_code_analysis is specified add the /analyze switch to enable
+    # static analysis. Specifying /analyze:WX- says that /analyze warnings
+    # should not be treated as errors.
+    cflags = [ "/analyze:WX-" ]
+
+    # Also, disable various noisy warnings that have low value.
+    cflags += [
+      "/wd6011",  # Dereferencing NULL pointer
+
+      # C6285 is ~16% of raw warnings and has low value
+      "/wd6285",  # non-zero constant || non-zero constant
+      "/wd6308",  # realloc might return null pointer
+
+      # Possible infinite loop: use of the constant
+      # EXCEPTION_CONTINUE_EXECUTION in the exception-filter
+      "/wd6312",
+
+      "/wd6322",  # Empty _except block
+      "/wd6330",  # 'char' used instead of 'unsigned char' for istype() call
+
+      # C6334 is ~80% of raw warnings and has low value
+      "/wd6334",  # sizeof applied to an expression with an operator
+      "/wd6326",  # Potential comparison of constant with constant
+      "/wd6340",  # Sign mismatch in function parameter
+      "/wd28159",  # Consider using 'GetTickCount64'
+      "/wd28196",  # The precondition is not satisfied
+      "/wd28204",  # Inconsistent SAL annotations
+      "/wd28251",  # Inconsistent SAL annotations
+      "/wd28252",  # Inconsistent SAL annotations
+      "/wd28253",  # Inconsistent SAL annotations
+      "/wd28278",  # Function appears with no prototype in scope
+      "/wd28285",  # syntax error in SAL annotation (in algorithm)
+      "/wd28301",  # Inconsistent SAL annotations
+      "/wd28182",  # Dereferencing NULL pointer
+    ]
+  }
+}
+
 # This is included by reference in the //build/config/compiler:runtime_library
 # config that is applied to all targets. It is here to separate out the logic
 # that is Windows-only. Please see that target for advice on what should go in
@@ -105,10 +153,13 @@ config("runtime_library") {
     "PSAPI_VERSION=1",
     "WIN32",
     "_SECURE_ATL",
+  ]
 
+  if (!use_vs_code_analysis) {
     # This is required for ATL to use XP-safe versions of its functions.
-    "_USING_V110_SDK71_",
-  ]
+    # However it is prohibited when using /analyze
+    defines += [ "_USING_V110_SDK71_" ]
+  }
 
   if (is_component_build) {
     # Component mode: dynamic CRT. Since the library is shared, it requires