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| author | Zack Weinberg <zackw@panix.com> | 2016-11-21 08:16:27 -0500 |
|---|---|---|
| committer | Zack Weinberg <zackw@panix.com> | 2017-02-25 09:47:51 -0500 |
| commit | 7caa5054afc1754a871333b1539e08a4af79444e (patch) | |
| tree | a88f80370a89a6a7a2b2e26d3e3f0f51131fef32 /include/features.h | |
| parent | 4f5a9afffb7f1fdb330b0f8dcca196a439ac07a8 (diff) | |
| download | glibc-7caa5054afc1754a871333b1539e08a4af79444e.tar.gz glibc-7caa5054afc1754a871333b1539e08a4af79444e.tar.xz glibc-7caa5054afc1754a871333b1539e08a4af79444e.zip | |
Clean up conditionals for declaration of gets.
gets has the dubious honor of being the only C89 library feature that
has been completely removed from the current C and C++ standards.
glibc follows suit by not declaring it in _GNU_SOURCE mode either,
but it remains present in older compatibility modes. Internally,
two test cases need to see stdio.h make the declaration, but all our
internal code is of course compiled under _GNU_SOURCE. This is currently
kludged by duplicating the gets declaration, fortify wrapper and all,
in include/stdio.h. Also, the conditional in the public headers for
deciding when to declare gets is complicated and repeated in two places.
This patch adds a new macro to features.h that encapsulates the
complicated rule for when to declare gets. stdio.h and bits/stdio2.h
then simply test __GLIBC_USE (DEPRECATED_GETS), and instead of having
a duplicate gets declaration in include/stdio.h, debug/tst-chk1.c and
stdio-common/tst-gets.c can force gets to be declared.
* include/features.h (__GLIBC_USE_DEPRECATED_GETS): New macro.
* libio/stdio.h, libio/bits/stdio2.h: Condition gets on
__GLIBC_USE (DEPRECATED_GETS). Update comments to indicate
gets was removed from C++ in C++14.
* include/stdio.h: Remove redundant declaration of gets.
* debug/tst-chk1.c, stdio-common/tst-gets.c: Force gets to
be declared, since we are testing it.
* stdio-common/Makefile (tst-gets.c): Compile with
-Wno-deprecated-declarations.
* debug/Makefile (tst-chk1.c, tst-chk2.c, tst-chk3.c, tst-chk4.cc)
(tst-chk5.cc, tst-chk6.cc, tst-lfschk1.c, tst-lfschk2.c)
(tst-lfschk3.c, tst-lfschk4.cc, tst-lfschk5.cc, tst-lfschk6.cc):
Compile with -Wno-deprecated-declarations.
Diffstat (limited to 'include/features.h')
| -rw-r--r-- | include/features.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/features.h b/include/features.h index dc8ae794a5..7de4089ed3 100644 --- a/include/features.h +++ b/include/features.h @@ -136,6 +136,7 @@ #undef __USE_GNU #undef __USE_FORTIFY_LEVEL #undef __KERNEL_STRICT_NAMES +#undef __GLIBC_USE_DEPRECATED_GETS /* Suppress kernel-name space pollution unless user expressedly asks for it. */ @@ -383,6 +384,16 @@ # define __USE_FORTIFY_LEVEL 0 #endif +/* The function 'gets' existed in C89, but is impossible to use + safely. It has been removed from ISO C11 and ISO C++14. Note: for + compatibility with various implementations of <cstdio>, this test + must consider only the value of __cplusplus when compiling C++. */ +#if defined __cplusplus ? __cplusplus >= 201402L : defined __USE_ISOC11 +# define __GLIBC_USE_DEPRECATED_GETS 0 +#else +# define __GLIBC_USE_DEPRECATED_GETS 1 +#endif + /* Get definitions of __STDC_* predefined macros, if the compiler has not preincluded this header automatically. */ #include <stdc-predef.h> |