Implement tracing interface for v8

build/standalone.gypi

Index: build/standalone.gypi
diff --git a/build/standalone.gypi b/build/standalone.gypi
index 4c1a702033254e5a18779ff0256a7bb406a342a5..6ac4f0d1c197df00b99cb325941b482d37a368c9 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -675,6 +675,7 @@
           '-pedantic',
           # Don't warn about the "struct foo f = {0};" initialization pattern.
           '-Wno-missing-field-initializers',
+          '-Wno-gnu-zero-variadic-macro-arguments',
         ],
         'cflags_cc': [
           '-Wnon-virtual-dtor',
@@ -684,6 +685,16 @@
         ],
         'ldflags': [ '-pthread', ],
         'conditions': [
+          # Don't warn about TRACE_EVENT_* macros with zero arguments passed to
+          # ##__VA_ARGS__. C99 strict mode prohibits having zero variadic macro
+          # arguments in gcc.
+          [ 'clang==0', {
+            'cflags!' : [
+              '-pedantic' ,
+              # Don't warn about unrecognized command line option.
+              '-Wno-gnu-zero-variadic-macro-arguments',
+            ],
+          }],
           [ 'clang==1 and (v8_target_arch=="x64" or v8_target_arch=="arm64" \
             or v8_target_arch=="mips64el")', {
             'cflags': [ '-Wshorten-64-to-32' ],
@@ -710,6 +721,7 @@
           '-Wno-unused-parameter',
           # Don't warn about the "struct foo f = {0};" initialization pattern.
           '-Wno-missing-field-initializers',
+          '-Wno-gnu-zero-variadic-macro-arguments',
         ],
         'cflags_cc': [
           '-Wnon-virtual-dtor',
@@ -934,6 +946,7 @@
             '-Wno-unused-parameter',
             # Don't warn about the "struct foo f = {0};" initialization pattern.
             '-Wno-missing-field-initializers',
+            '-Wno-gnu-zero-variadic-macro-arguments',
           ],
         },
         'conditions': [