fix: drop custom (v)snprintf definition (#992)

The functions are available since C++11.

CMakeLists.txt

@@ -151,10 +151,6 @@ endif (Threads_FOUND)
 check_cxx_symbol_exists (pthread_threadid_np "pthread.h" HAVE_PTHREAD_THREADID_NP)
 cmake_pop_check_state ()
 
-# NOTE: Cannot use check_function_exists here since >=vc-14.0 can define
-# snprintf as an inline function
-check_cxx_symbol_exists (snprintf cstdio HAVE_SNPRINTF)
-
 cmake_push_check_state (RESET)
 set (CMAKE_REQUIRED_LIBRARIES dbghelp)
 check_cxx_symbol_exists (UnDecorateSymbolName "windows.h;dbghelp.h" HAVE_DBGHELP)

bazel/glog.bzl

@@ -113,7 +113,6 @@ def glog_library(namespace = "google", with_gflags = 1, **kwargs):
         # Override -DGLOG_EXPORT= from the cc_library's defines.
         "-DGLOG_EXPORT=__declspec(dllexport)",
         "-DGLOG_NO_ABBREVIATED_SEVERITIES",
-        "-DHAVE_SNPRINTF",
         "-DHAVE__CHSIZE_S",
         "-I" + src_windows,
     ]

src/config.h.cmake.in

@@ -7,9 +7,6 @@
 /* Define if you have the `dladdr' function */
 #cmakedefine HAVE_DLADDR
 
-/* Define if you have the `snprintf' function */
-#cmakedefine HAVE_SNPRINTF
-
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #cmakedefine HAVE_DLFCN_H
 

src/googletest.h

@@ -487,8 +487,9 @@ static inline string Munge(const string& filename) {
     const size_t str_size = 256;
     char null_str[str_size];
     char ptr_str[str_size];
-    snprintf(null_str, str_size, "%p", static_cast<void*>(nullptr));
-    snprintf(ptr_str, str_size, "%p", reinterpret_cast<void*>(PTR_TEST_VALUE));
+    std::snprintf(null_str, str_size, "%p", static_cast<void*>(nullptr));
+    std::snprintf(ptr_str, str_size, "%p",
+                  reinterpret_cast<void*>(PTR_TEST_VALUE));
 
     StringReplace(&line, "__NULLP__", null_str);
     StringReplace(&line, "__PTRTEST__", ptr_str);

src/logging.cc

@@ -1699,7 +1699,7 @@ void LogMessage::Init(const char* file,
 
   if (!FLAGS_log_backtrace_at.empty()) {
     char fileline[128];
-    snprintf(fileline, sizeof(fileline), "%s:%d", data_->basename_, line);
+    std::snprintf(fileline, sizeof(fileline), "%s:%d", data_->basename_, line);
 #ifdef HAVE_STACKTRACE
     if (FLAGS_log_backtrace_at == fileline) {
       string stacktrace;
@@ -2614,7 +2614,7 @@ string StrError(int err) {
   char buf[100];
   int rc = posix_strerror_r(err, buf, sizeof(buf));
   if ((rc < 0) || (buf[0] == '\000')) {
-    snprintf(buf, sizeof(buf), "Error number %d", err);
+    std::snprintf(buf, sizeof(buf), "Error number %d", err);
   }
   return buf;
 }

src/logging_unittest.cc

@@ -1006,7 +1006,7 @@ static void TestTruncate() {
   int fd;
   CHECK_ERR(fd = open(path.c_str(), O_APPEND | O_WRONLY));
   char fdpath[64];
-  snprintf(fdpath, sizeof(fdpath), "/proc/self/fd/%d", fd);
+  std::snprintf(fdpath, sizeof(fdpath), "/proc/self/fd/%d", fd);
   TestOneTruncate(fdpath, 10, 10, 10, 10, 10);
 #endif
 
@@ -1435,7 +1435,8 @@ TEST(LogBacktraceAt, DoesBacktraceAtRightLineWhenEnabled) {
   StrictMock<ScopedMockLog> log;
 
   char where[100];
-  snprintf(where, 100, "%s:%d", const_basename(__FILE__), kBacktraceAtLine);
+  std::snprintf(where, 100, "%s:%d", const_basename(__FILE__),
+                kBacktraceAtLine);
   FLAGS_log_backtrace_at = where;
 
   // The LOG at the specified line should include a stacktrace which includes

src/raw_logging.cc

@@ -82,10 +82,10 @@ _START_GOOGLE_NAMESPACE_
 #define GLOG_ATTRIBUTE_FORMAT_ARG(stringIndex)
 #endif
 
-// CAVEAT: vsnprintf called from *DoRawLog below has some (exotic) code paths
-// that invoke malloc() and getenv() that might acquire some locks.
-// If this becomes a problem we should reimplement a subset of vsnprintf
-// that does not need locks and malloc.
+// CAVEAT: std::vsnprintf called from *DoRawLog below has some (exotic) code
+// paths that invoke malloc() and getenv() that might acquire some locks. If
+// this becomes a problem we should reimplement a subset of std::vsnprintf that
+// does not need locks and malloc.
 
 // Helper for RawLog__ below.
 // *DoRawLog writes to *buf of *size and move them past the written portion.
@@ -94,7 +94,7 @@ GLOG_ATTRIBUTE_FORMAT(printf, 3, 4)
 static bool DoRawLog(char** buf, size_t* size, const char* format, ...) {
   va_list ap;
   va_start(ap, format);
-  int n = vsnprintf(*buf, *size, format, ap);
+  int n = std::vsnprintf(*buf, *size, format, ap);
   va_end(ap);
   if (n < 0 || static_cast<size_t>(n) > *size) return false;
   *size -= static_cast<size_t>(n);
@@ -109,7 +109,7 @@ inline static bool VADoRawLog(char** buf, size_t* size,
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
 #endif
-  int n = vsnprintf(*buf, *size, format, ap);
+  int n = std::vsnprintf(*buf, *size, format, ap);
 #if defined(__GNUC__)
 #pragma GCC diagnostic pop
 #endif

src/stl_logging_unittest.cc

@@ -82,7 +82,7 @@ static void TestSTLLogging() {
       if (i > 0) expected += ' ';
       const size_t buf_size = 256;
       char buf[buf_size];
-      snprintf(buf, buf_size, "%d", i);
+      std::snprintf(buf, buf_size, "%d", i);
       expected += buf;
     }
     v.push_back(100);

src/symbolize.cc

@@ -391,7 +391,7 @@ struct FileDescriptor {
 //
 // Note: we don't use ProcMapsIterator since the object is big (it has
 // a 5k array member) and uses async-unsafe functions such as sscanf()
-// and snprintf().
+// and std::snprintf().
 class LineReader {
  public:
   explicit LineReader(int fd, char *buf, size_t buf_len, size_t offset)

src/utilities.cc

@@ -120,17 +120,17 @@ static void DumpPCAndSymbol(DebugWriter *writerfn, void *arg, void *pc,
       symbol = tmp;
   }
   char buf[1024];
-  snprintf(buf, sizeof(buf), "%s@ %*p  %s\n",
-           prefix, kPrintfPointerFieldWidth, pc, symbol);
+  std::snprintf(buf, sizeof(buf), "%s@ %*p  %s\n", prefix,
+                kPrintfPointerFieldWidth, pc, symbol);
   writerfn(buf, arg);
 }
 #endif
 
 static void DumpPC(DebugWriter *writerfn, void *arg, void *pc,
                    const char * const prefix) {
   char buf[100];
-  snprintf(buf, sizeof(buf), "%s@ %*p\n",
-           prefix, kPrintfPointerFieldWidth, pc);
+  std::snprintf(buf, sizeof(buf), "%s@ %*p\n", prefix, kPrintfPointerFieldWidth,
+                pc);
   writerfn(buf, arg);
 }
 
@@ -334,7 +334,7 @@ static void MyUserNameInitializer() {
     if (pwuid_res == 0 && result) {
       g_my_user_name = pwd.pw_name;
     } else {
-      snprintf(buffer, sizeof(buffer), "uid%d", uid);
+      std::snprintf(buffer, sizeof(buffer), "uid%d", uid);
       g_my_user_name = buffer;
     }
 #endif

src/windows/port.cc

@@ -1,4 +1,4 @@
-/* Copyright (c) 2008, Google Inc.
+/* Copyright (c) 2023, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -38,20 +38,10 @@
 
 #include "port.h"
 
-#include <cstdarg>  // for va_list, va_start, va_end
 #include <ctime>
 
 #include "config.h"
 
-// These call the windows _vsnprintf, but always NUL-terminate.
-int safe_vsnprintf(char* str, std::size_t size, const char* format,
-                   va_list ap) {
-  if (size == 0)        // not even room for a \0?
-    return -1;          // not what C99 says to do, but what windows does
-  str[size-1] = '\0';
-  return _vsnprintf(str, size-1, format, ap);
-}
-
 #ifndef HAVE_LOCALTIME_R
 struct tm* localtime_r(const std::time_t* timep, std::tm* result) {
   localtime_s(result, timep);
@@ -63,13 +53,4 @@ struct tm* gmtime_r(const std::time_t* timep, std::tm* result) {
   gmtime_s(result, timep);
   return result;
 }
-#endif // not HAVE_GMTIME_R
-#ifndef HAVE_SNPRINTF
-int snprintf(char *str, size_t size, const char *format, ...) {
-  va_list ap;
-  va_start(ap, format);
-  const int r = vsnprintf(str, size, format, ap);
-  va_end(ap);
-  return r;
-}
-#endif
+#endif  // not HAVE_GMTIME_R

src/windows/port.h

@@ -56,7 +56,6 @@
 #include <winsock.h> /* for gethostname */
 
 #include <cstdarg> /* template_dictionary.cc uses va_copy */
-#include <cstdio>  /* read in vsnprintf decl. before redefining it */
 #include <cstring> /* for _strnicmp(), strerror_s() */
 #include <ctime>   /* for localtime_s() */
 /* Note: the C++ #includes are all together at the bottom.  This file is
@@ -111,21 +110,6 @@ enum { STDIN_FILENO = 0, STDOUT_FILENO = 1, STDERR_FILENO = 2 };
 /* Sleep is in ms, on windows */
 #define sleep(secs)  Sleep((secs) * 1000)
 
-/* We can't just use _vsnprintf and _snprintf as drop-in-replacements,
- * because they don't always NUL-terminate. :-(  We also can't use the
- * name vsnprintf, since windows defines that (but not snprintf (!)).
- */
-#ifndef HAVE_SNPRINTF
-extern int GLOG_EXPORT snprintf(char* str, size_t size, const char* format,
-                                ...);
-#endif
-extern int GLOG_EXPORT safe_vsnprintf(char* str, size_t size,
-                                      const char* format, va_list ap);
-#define vsnprintf(str, size, format, ap)  safe_vsnprintf(str, size, format, ap)
-#ifndef va_copy
-#define va_copy(dst, src)  (dst) = (src)
-#endif
-
 /* Windows doesn't support specifying the number of buckets as a
  * hash_map constructor arg, so we leave this blank.
  */