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.
diff --git a/googletest/include/gtest/internal/gtest-port.h b/googletest/include/gtest/internal/gtest-port.h
index 60ff471..c7c79ae 100644
--- a/googletest/include/gtest/internal/gtest-port.h
+++ b/googletest/include/gtest/internal/gtest-port.h
@@ -252,6 +252,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <cerrno>
#include <cstdint>
#include <limits>
#include <type_traits>
@@ -1960,16 +1961,16 @@
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 @@
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 @@
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 @@
#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_()
