From a1b0173df92bbbad69254f929e341f8dbf1cc708 Mon Sep 17 00:00:00 2001 From: Romain Geissler Date: Wed, 11 Mar 2020 22:30:20 +0000 Subject: Make sure IsATTY does not clobber errno. Exposition of the problem: > cat main.cpp TEST(errnoTest, errnoTest) { ASSERT_EQ(errno, 0); } int main(int argc, char** argv) { ::testing::InitGoogleTest(&argc, argv); return RUN_ALL_TESTS(); } Compiled with gcc 10 like this: > g++ -pthread -o runtest main.cpp -Wl,-Bstatic -lgtest -Wl,-Bdynamic Before patch: > ./runtest [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from errnoTest [ RUN ] errnoTest.errnoTest [ OK ] errnoTest.errnoTest (0 ms) [----------] 1 test from errnoTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test. (output is colored, I run this inside an interactive terminal). > ./runtest | cat [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from errnoTest [ RUN ] errnoTest.errnoTest main.cpp:5: Failure Expected equality of these values: (*__errno_location ()) Which is: 25 0 [ FAILED ] errnoTest.errnoTest (0 ms) [----------] 1 test from errnoTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 0 tests. [ FAILED ] 1 test, listed below: [ FAILED ] errnoTest.errnoTest 1 FAILED TEST (output is not colored, since IsTTY return false, because of the pipe, however it also clobbered errno for the tests). After the patch, both cases are working fine: > ./runtest [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from errnoTest [ RUN ] errnoTest.errnoTest [ OK ] errnoTest.errnoTest (0 ms) [----------] 1 test from errnoTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test. > ./runtest | cat [==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from errnoTest [ RUN ] errnoTest.errnoTest [ OK ] errnoTest.errnoTest (0 ms) [----------] 1 test from errnoTest (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test. --- googletest/include/gtest/internal/gtest-port.h | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/googletest/include/gtest/internal/gtest-port.h b/googletest/include/gtest/internal/gtest-port.h index 60ff4716..c7c79ae5 100644 --- a/googletest/include/gtest/internal/gtest-port.h +++ b/googletest/include/gtest/internal/gtest-port.h @@ -252,6 +252,7 @@ #include #include #include +#include #include #include #include @@ -1960,16 +1961,16 @@ namespace posix { typedef struct _stat StatStruct; # ifdef __BORLANDC__ -inline int IsATTY(int fd) { return isatty(fd); } +inline int DoIsATTY(int fd) { return isatty(fd); } inline int StrCaseCmp(const char* s1, const char* s2) { return stricmp(s1, s2); } inline char* StrDup(const char* src) { return strdup(src); } # else // !__BORLANDC__ # if GTEST_OS_WINDOWS_MOBILE -inline int IsATTY(int /* fd */) { return 0; } +inline int DoIsATTY(int /* fd */) { return 0; } # else -inline int IsATTY(int fd) { return _isatty(fd); } +inline int DoIsATTY(int fd) { return _isatty(fd); } # endif // GTEST_OS_WINDOWS_MOBILE inline int StrCaseCmp(const char* s1, const char* s2) { return _stricmp(s1, s2); @@ -1994,7 +1995,7 @@ inline bool IsDir(const StatStruct& st) { typedef struct stat StatStruct; inline int FileNo(FILE* file) { return fileno(file); } -inline int IsATTY(int fd) { return isatty(fd); } +inline int DoIsATTY(int fd) { return isatty(fd); } inline int Stat(const char* path, StatStruct* buf) { // stat function not implemented on ESP8266 return 0; @@ -2011,7 +2012,7 @@ inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); } typedef struct stat StatStruct; inline int FileNo(FILE* file) { return fileno(file); } -inline int IsATTY(int fd) { return isatty(fd); } +inline int DoIsATTY(int fd) { return isatty(fd); } inline int Stat(const char* path, StatStruct* buf) { return stat(path, buf); } inline int StrCaseCmp(const char* s1, const char* s2) { return strcasecmp(s1, s2); @@ -2022,6 +2023,18 @@ inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); } #endif // GTEST_OS_WINDOWS +inline int IsATTY(int fd) +{ + // DoIsATTY might change errno (for example ENOTTY in case you redirect stdout + // to a file on Linux), which is unexpected, so save the previous value, and + // restore it after the call. + int savedErrno = errno; + int isAttyValue = DoIsATTY(fd); + errno = savedErrno; + + return isAttyValue; +} + // Functions deprecated by MSVC 8.0. GTEST_DISABLE_MSC_DEPRECATED_PUSH_() -- cgit v1.2.3