GoogleTest 1.6 with Cygwin 1.7 compile error: 'fileno' was not declared in this scope

Question

GoogleTest 1.6 with Cygwin 1.7: \'fileno\' was not declared in this scope

Error message when building a simple test on Factorial() function in Eclipse CDT:

Answer 1

Some functions go beyond the ANSI standard. These are disabled when you use std=c++11 (or std=c++0x).

Among them are fdopen, fileno and strdup. There are two possibilities to use them:

• Use the GNU dialect (std=gnu++11).
• If you want to compile without dialect and make a local exception, you can include stdio.h with the __STRICT_ANSI__ undefined. (see: Error "'fdopen' was not declared" found with g++ 4 that compiled with g++3)

I have tested both on Suse Linux Enterprise 11, MinGW and Cygwin.

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Addition: Another (possibly better) way to access non-ANSI symbols would be to add

#define _POSIX_C_SOURCE 200809L

before the first #include in your file. This will give you access to most of the non-standard routines.

Some functions (e.g. realpath(...)) require

#define _BSD_SOURCE

to be inserted on top of your file.

Answer 2

Setting the C++ standard to -std=gnu++0x rather than -std=c++0x, worked for me. You can try the statement:

g++ -std=gnu++0x -DGTEST_OS_CYGWIN=1 -I"E:\source\gtest-1.6.0\include" -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/challenge.d" -MT"src/challenge.d" -o "src/challenge.o" "../src/challenge.cpp"

Setting symbol (-DGTEST_OS_CYGWIN=1) has got nothing to do with this error.