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Update the conformance description.

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Joseph Myers 2009-08-25 13:08:04 -07:00 committed by Ulrich Drepper
parent 8392ff2dc7
commit 625c963390
1 changed files with 11 additions and 17 deletions
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28
CONFORMANCE
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@ -125,7 +125,9 @@ C99 added %a as another scanf format specifier for floating point
values. This conflicts with the glibc extension where %as, %a[ and values. This conflicts with the glibc extension where %as, %a[ and
%aS mean to allocate the string for the data read. A strictly %aS mean to allocate the string for the data read. A strictly
conforming C99 program using %as, %a[ or %aS in a scanf format string conforming C99 program using %as, %a[ or %aS in a scanf format string
will misbehave under glibc. will misbehave under glibc if it does not include <stdio.h> and
instead declares scanf itself; if it gets the declaration of scanf
from <stdio.h>, it will use a C99-conforming version.
Compiler limitations Compiler limitations
@ -144,29 +146,21 @@ GCC doesn't support the optional imaginary types. Nor does it
understand the keyword _Complex before GCC 3.0. This has the understand the keyword _Complex before GCC 3.0. This has the
corresponding impact on the relevant headers. corresponding impact on the relevant headers.
glibc's use of extern inline conflicts with C99: in C99, extern inline
means that an external definition is generated as well as possibly an
inline definition, but in GCC it means that no external definition is
generated. When GCC's C99 mode implements C99 inline semantics, this
will break the uses of extern inline in glibc's headers. (Actually,
glibc uses `extern __inline', which is beyond the scope of the
standard, but it would clearly be very confusing for `__inline' and
plain `inline' to have different meanings in C99 mode.)
glibc's <tgmath.h> implementation is arcane but thought to work glibc's <tgmath.h> implementation is arcane but thought to work
correctly; a clean and comprehensible version requires compiler correctly; a clean and comprehensible version requires compiler
builtins. builtins.
For most of the headers required of freestanding implementations, For most of the headers required of freestanding implementations,
glibc relies on GCC to provide correct versions. (At present, glibc glibc relies on GCC to provide correct versions. (At present, glibc
provides <stdint.h>, and GCC doesn't.) provides <stdint.h>, and GCC doesn't before version 4.5.)
Implementing MATH_ERRNO, MATH_ERREXCEPT and math_errhandling in The definition of math_errhandling conforms so long as no translation
<math.h> needs compiler support: see unit using math_errhandling is compiled with -fno-math-errno,
-fno-trapping-math or options such as -ffast-math that imply these
http://sources.redhat.com/ml/libc-hacker/2000-06/msg00008.html options. math_errhandling is only conditionally defined depending on
http://sources.redhat.com/ml/libc-hacker/2000-06/msg00014.html __FAST_MATH__; the compiler does not provide the information needed
http://sources.redhat.com/ml/libc-hacker/2000-06/msg00015.html for more exact definitions based on settings of -fno-math-errno and
-fno-trapping-math, possibly for only some source files in a program.
Issues with headers Issues with headers