Remove GG_VA_COPY in favor of va_copy

This was a workaround for VS's before 2013 that lack va_copy, and is
no longer required. The unittest is removed as it seems unnecessary
to test the standard library's implementation of va_copy.

R=thakis@chromium.org
TBR=cpu@chromium.org

Review URL: https://codereview.chromium.org/802533002

Cr-Commit-Position: refs/heads/master@{#307991}

base/port.h

@@ -26,18 +26,6 @@
 #define GG_INT64_C(x)   GG_LONGLONG(x)
 #define GG_UINT64_C(x)  GG_ULONGLONG(x)
 
-// It's possible for functions that use a va_list, such as StringPrintf, to
-// invalidate the data in it upon use.  The fix is to make a copy of the
-// structure before using it and use that copy instead.  va_copy is provided
-// for this purpose.  MSVC does not provide va_copy, so define an
-// implementation here.  It is not guaranteed that assignment is a copy, so the
-// StringUtil.VariableArgsFunc unit test tests this capability.
-#if defined(COMPILER_GCC)
-#define GG_VA_COPY(a, b) (va_copy(a, b))
-#elif defined(COMPILER_MSVC)
-#define GG_VA_COPY(a, b) (a = b)
-#endif
-
 // Define an OS-neutral wrapper for shared library entry points
 #if defined(OS_WIN)
 #define API_CALL __stdcall

base/strings/string_util_unittest.cc

@@ -669,39 +669,6 @@ TEST(StringUtilTest, HexDigitToInt) {
   EXPECT_EQ(15, HexDigitToInt('f'));
 }
 
-// This checks where we can use the assignment operator for a va_list. We need
-// a way to do this since Visual C doesn't support va_copy, but assignment on
-// va_list is not guaranteed to be a copy. See StringAppendVT which uses this
-// capability.
-static void VariableArgsFunc(const char* format, ...) {
-  va_list org;
-  va_start(org, format);
-
-  va_list dup;
-  GG_VA_COPY(dup, org);
-  int i1 = va_arg(org, int);
-  int j1 = va_arg(org, int);
-  char* s1 = va_arg(org, char*);
-  double d1 = va_arg(org, double);
-  va_end(org);
-
-  int i2 = va_arg(dup, int);
-  int j2 = va_arg(dup, int);
-  char* s2 = va_arg(dup, char*);
-  double d2 = va_arg(dup, double);
-
-  EXPECT_EQ(i1, i2);
-  EXPECT_EQ(j1, j2);
-  EXPECT_STREQ(s1, s2);
-  EXPECT_EQ(d1, d2);
-
-  va_end(dup);
-}
-
-TEST(StringUtilTest, VAList) {
-  VariableArgsFunc("%d %d %s %lf", 45, 92, "This is interesting", 9.21);
-}
-
 // Test for Tokenize
 template <typename STR>
 void TokenizeTest() {

base/strings/stringprintf.cc

@@ -48,7 +48,7 @@ static void StringAppendVT(StringType* dst,
   typename StringType::value_type stack_buf[1024];
 
   va_list ap_copy;
-  GG_VA_COPY(ap_copy, ap);
+  va_copy(ap_copy, ap);
 
 #if !defined(OS_WIN)
   ScopedClearErrno clear_errno;
@@ -94,7 +94,7 @@ static void StringAppendVT(StringType* dst,
 
     // NOTE: You can only use a va_list once.  Since we're in a while loop, we
     // need to make a new copy each time so we don't use up the original.
-    GG_VA_COPY(ap_copy, ap);
+    va_copy(ap_copy, ap);
     result = vsnprintfT(&mem_buf[0], mem_length, format, ap_copy);
     va_end(ap_copy);
 

third_party/cld/base/port.h

@@ -32,18 +32,6 @@
 #define GG_UINT32_C(x)  (x ## U)
 #define GG_UINT64_C(x)  GG_ULONGLONG(x)
 
-// It's possible for functions that use a va_list, such as StringPrintf, to
-// invalidate the data in it upon use.  The fix is to make a copy of the
-// structure before using it and use that copy instead.  va_copy is provided
-// for this purpose.  MSVC does not provide va_copy, so define an
-// implementation here.  It is not guaranteed that assignment is a copy, so the
-// StringUtil.VariableArgsFunc unit test tests this capability.
-#if defined(COMPILER_GCC)
-#define GG_VA_COPY(a, b) (va_copy(a, b))
-#elif defined(COMPILER_MSVC)
-#define GG_VA_COPY(a, b) (a = b)
-#endif
-
 // Define an OS-neutral wrapper for shared library entry points
 #if defined(OS_WIN)
 #define API_CALL __stdcall

third_party/leveldatabase/chromium_logger.h

@@ -54,7 +54,7 @@ class ChromiumLogger : public Logger {
       // Print the message
       if (p < limit) {
         va_list backup_ap;
-        GG_VA_COPY(backup_ap, ap);
+        va_copy(backup_ap, ap);
         p += vsnprintf(p, limit - p, format, backup_ap);
         va_end(backup_ap);
       }