diff options
Diffstat (limited to 'gnu/usr.bin/gcc/cpp.texi')
| -rw-r--r-- | gnu/usr.bin/gcc/cpp.texi | 60 |
1 files changed, 29 insertions, 31 deletions
diff --git a/gnu/usr.bin/gcc/cpp.texi b/gnu/usr.bin/gcc/cpp.texi index 9424b48f985..fb730e2ef23 100644 --- a/gnu/usr.bin/gcc/cpp.texi +++ b/gnu/usr.bin/gcc/cpp.texi @@ -934,7 +934,7 @@ to test whether a header is compiled by a C compiler or a C++ compiler. @item __STRICT_ANSI__ @findex __STRICT_ANSI__ -This macro is defined if and only if the @samp{-ansi} switch was +GNU C defines this macro if and only if the @samp{-ansi} switch was specified when GNU C was invoked. Its definition is the null string. This macro exists primarily to direct certain GNU header files not to define certain traditional Unix constructs which are incompatible with @@ -956,48 +956,46 @@ the nesting level is zero. @item __VERSION__ @findex __VERSION__ -This macro expands to a string which describes the version number of +This macro expands to a string constant which describes the version number of GNU C@. The string is normally a sequence of decimal numbers separated -by periods, such as @samp{"2.6.0"}. The only reasonable use of this -macro is to incorporate it into a string constant. +by periods, such as @samp{"2.6.0"}. @item __OPTIMIZE__ @findex __OPTIMIZE__ -This macro is defined in optimizing compilations. It causes certain -GNU header files to define alternative macro definitions for some -system library functions. It is unwise to refer to or test the -definition of this macro unless you make very sure that programs will -execute with the same effect regardless. +GNU CC defines this macro in optimizing compilations. It causes certain +GNU header files to define alternative macro definitions for some system +library functions. You should not refer to or test the definition of +this macro unless you make very sure that programs will execute with the +same effect regardless. @item __CHAR_UNSIGNED__ @findex __CHAR_UNSIGNED__ -This macro is defined if and only if the data type @code{char} is -unsigned on the target machine. It exists to cause the standard -header file @file{limits.h} to work correctly. It is bad practice -to refer to this macro yourself; instead, refer to the standard -macros defined in @file{limits.h}. The preprocessor uses -this macro to determine whether or not to sign-extend large character -constants written in octal; see @ref{#if Directive,,The @samp{#if} Directive}. +GNU C defines this macro if and only if the data type @code{char} is +unsigned on the target machine. It exists to cause the standard header +file @file{limits.h} to work correctly. You should not refer to this +macro yourself; instead, refer to the standard macros defined in +@file{limits.h}. The preprocessor uses this macro to determine whether +or not to sign-extend large character constants written in octal; see +@ref{#if Directive,,The @samp{#if} Directive}. @item __REGISTER_PREFIX__ @findex __REGISTER_PREFIX__ -This macro expands to a string describing the prefix applied to cpu -registers in assembler code. It can be used to write assembler code -that is usable in multiple environments. For example, in the -@samp{m68k-aout} environment it expands to the string @samp{""}, -but in the @samp{m68k-coff} environment it expands to the string -@samp{"%"}. +This macro expands to a string (not a string constant) describing the +prefix applied to CPU registers in assembler code. You can use it to +write assembler code that is usable in multiple environments. For +example, in the @samp{m68k-aout} environment it expands to the null +string, but in the @samp{m68k-coff} environment it expands to the string +@samp{%}. @item __USER_LABEL_PREFIX__ @findex __USER_LABEL_PREFIX__ -This macro expands to a string describing the prefix applied to user -generated labels in assembler code. It can be used to write assembler -code that is usable in multiple environments. For example, in the -@samp{m68k-aout} environment it expands to the string @samp{"_"}, but in -the @samp{m68k-coff} environment it expands to the string @samp{""}. -This does not work with the @samp{-mno-underscores} option that the -i386 OSF/rose and m88k targets provide nor with the @samp{-mcall*} options -of the rs6000 System V Release 4 target. +Similar to @code{__REGISTER_PREFIX__}, but describes the prefix applied +to user generated labels in assembler code. For example, in the +@samp{m68k-aout} environment it expands to the string @samp{_}, but in +the @samp{m68k-coff} environment it expands to the null string. This +does not work with the @samp{-mno-underscores} option that the i386 +OSF/rose and m88k targets provide nor with the @samp{-mcall*} options of +the rs6000 System V Release 4 target. @end table @node Nonstandard Predefined,, Standard Predefined, Predefined @@ -2687,7 +2685,7 @@ Only the directories you have specified with @samp{-I} options @findex -nostdinc++ Do not search for header files in the C++-specific standard directories, but do still search the other standard directories. -(This option is used when building libg++.) +(This option is used when building the C++ library.) @item -remap @findex -remap |