| // Protocol Buffers - Google's data interchange format |
| // Copyright 2012 Google Inc. All rights reserved. |
| // https://developers.google.com/protocol-buffers/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // from google3/base/stringprintf.cc |
| |
| #include <google/protobuf/stubs/stringprintf.h> |
| |
| #include <errno.h> |
| #include <stdarg.h> // For va_list and related operations |
| #include <stdio.h> // MSVC requires this for _vsnprintf |
| #include <vector> |
| #include <google/protobuf/stubs/common.h> |
| |
| namespace google { |
| namespace protobuf { |
| |
| #ifdef _MSC_VER |
| enum { IS_COMPILER_MSVC = 1 }; |
| #ifndef va_copy |
| // Define va_copy for MSVC. This is a hack, assuming va_list is simply a |
| // pointer into the stack and is safe to copy. |
| #define va_copy(dest, src) ((dest) = (src)) |
| #endif |
| #else |
| enum { IS_COMPILER_MSVC = 0 }; |
| #endif |
| |
| void StringAppendV(string* dst, const char* format, va_list ap) { |
| // First try with a small fixed size buffer |
| static const int kSpaceLength = 1024; |
| char space[kSpaceLength]; |
| |
| // It's possible for methods that use a va_list 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_list backup_ap; |
| va_copy(backup_ap, ap); |
| int result = vsnprintf(space, kSpaceLength, format, backup_ap); |
| va_end(backup_ap); |
| |
| if (result < kSpaceLength) { |
| if (result >= 0) { |
| // Normal case -- everything fit. |
| dst->append(space, result); |
| return; |
| } |
| |
| if (IS_COMPILER_MSVC) { |
| // Error or MSVC running out of space. MSVC 8.0 and higher |
| // can be asked about space needed with the special idiom below: |
| va_copy(backup_ap, ap); |
| result = vsnprintf(NULL, 0, format, backup_ap); |
| va_end(backup_ap); |
| } |
| |
| if (result < 0) { |
| // Just an error. |
| return; |
| } |
| } |
| |
| // Increase the buffer size to the size requested by vsnprintf, |
| // plus one for the closing \0. |
| int length = result+1; |
| char* buf = new char[length]; |
| |
| // Restore the va_list before we use it again |
| va_copy(backup_ap, ap); |
| result = vsnprintf(buf, length, format, backup_ap); |
| va_end(backup_ap); |
| |
| if (result >= 0 && result < length) { |
| // It fit |
| dst->append(buf, result); |
| } |
| delete[] buf; |
| } |
| |
| |
| string StringPrintf(const char* format, ...) { |
| va_list ap; |
| va_start(ap, format); |
| string result; |
| StringAppendV(&result, format, ap); |
| va_end(ap); |
| return result; |
| } |
| |
| const string& SStringPrintf(string* dst, const char* format, ...) { |
| va_list ap; |
| va_start(ap, format); |
| dst->clear(); |
| StringAppendV(dst, format, ap); |
| va_end(ap); |
| return *dst; |
| } |
| |
| void StringAppendF(string* dst, const char* format, ...) { |
| va_list ap; |
| va_start(ap, format); |
| StringAppendV(dst, format, ap); |
| va_end(ap); |
| } |
| |
| // Max arguments supported by StringPrintVector |
| const int kStringPrintfVectorMaxArgs = 32; |
| |
| // An empty block of zero for filler arguments. This is const so that if |
| // printf tries to write to it (via %n) then the program gets a SIGSEGV |
| // and we can fix the problem or protect against an attack. |
| static const char string_printf_empty_block[256] = { '\0' }; |
| |
| string StringPrintfVector(const char* format, const vector<string>& v) { |
| GOOGLE_CHECK_LE(v.size(), kStringPrintfVectorMaxArgs) |
| << "StringPrintfVector currently only supports up to " |
| << kStringPrintfVectorMaxArgs << " arguments. " |
| << "Feel free to add support for more if you need it."; |
| |
| // Add filler arguments so that bogus format+args have a harder time |
| // crashing the program, corrupting the program (%n), |
| // or displaying random chunks of memory to users. |
| |
| const char* cstr[kStringPrintfVectorMaxArgs]; |
| for (int i = 0; i < v.size(); ++i) { |
| cstr[i] = v[i].c_str(); |
| } |
| for (int i = v.size(); i < GOOGLE_ARRAYSIZE(cstr); ++i) { |
| cstr[i] = &string_printf_empty_block[0]; |
| } |
| |
| // I do not know any way to pass kStringPrintfVectorMaxArgs arguments, |
| // or any way to build a va_list by hand, or any API for printf |
| // that accepts an array of arguments. The best I can do is stick |
| // this COMPILE_ASSERT right next to the actual statement. |
| |
| GOOGLE_COMPILE_ASSERT(kStringPrintfVectorMaxArgs == 32, arg_count_mismatch); |
| return StringPrintf(format, |
| cstr[0], cstr[1], cstr[2], cstr[3], cstr[4], |
| cstr[5], cstr[6], cstr[7], cstr[8], cstr[9], |
| cstr[10], cstr[11], cstr[12], cstr[13], cstr[14], |
| cstr[15], cstr[16], cstr[17], cstr[18], cstr[19], |
| cstr[20], cstr[21], cstr[22], cstr[23], cstr[24], |
| cstr[25], cstr[26], cstr[27], cstr[28], cstr[29], |
| cstr[30], cstr[31]); |
| } |
| } // namespace protobuf |
| } // namespace google |