CbC/CbC_gcc: gcc/doc/cppopts.texi comparison

comparison gcc/doc/cppopts.texi @ 111:04ced10e8804

gcc 7

author	kono
date	Fri, 27 Oct 2017 22:46:09 +0900
parents	f6334be47118
children	84e7813d76e9

comparison

equal deleted inserted replaced

-:561a7518be6b
+:04ced10e8804
-@c Copyright (c) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+@c Copyright (C) 1999-2017 Free Software Foundation, Inc.
-@c 2010, Free Software Foundation, Inc.
 @c This is part of the CPP and GCC manuals.
 @c For copying conditions, see the file gcc.texi.
 @c ---------------------------------------------------------------------
 @c Options affecting the preprocessor
 @c ---------------------------------------------------------------------
 @c If this file is included with the flag ``cppmanual'' set, it is
 @c formatted for inclusion in the CPP manual; otherwise the main GCC manual.
-@table @gcctabopt
 @item -D @var{name}
 @opindex D
 Predefine @var{name} as a macro, with definition @code{1}.
 @item -D @var{name}=@var{definition}
 The contents of @var{definition} are tokenized and processed as if
 they appeared during translation phase three in a @samp{#define}
-directive.  In particular, the definition will be truncated by
+directive.  In particular, the definition is truncated by
 embedded newline characters.
 If you are invoking the preprocessor from a shell or shell-like
 program you may need to use the shell's quoting syntax to protect
 characters such as spaces that have a meaning in the shell syntax.
 If you wish to define a function-like macro on the command line, write
 its argument list with surrounding parentheses before the equals sign
-(if any).  Parentheses are meaningful to most shells, so you will need
+(if any).  Parentheses are meaningful to most shells, so you should
-to quote the option.  With @command{sh} and @command{csh},
+quote the option.  With @command{sh} and @command{csh},
 @option{-D'@var{name}(@var{args@dots{}})=@var{definition}'} works.
 @option{-D} and @option{-U} options are processed in the order they
 are given on the command line.  All @option{-imacros @var{file}} and
 @option{-include @var{file}} options are processed after all
 @item -U @var{name}
 @opindex U
 Cancel any previous definition of @var{name}, either built in or
 provided with a @option{-D} option.
+@item -include @var{file}
+@opindex include
+Process @var{file} as if @code{#include "file"} appeared as the first
+line of the primary source file.  However, the first directory searched
+for @var{file} is the preprocessor's working directory @emph{instead of}
+the directory containing the main source file.  If not found there, it
+is searched for in the remainder of the @code{#include "@dots{}"} search
+chain as normal.
+If multiple @option{-include} options are given, the files are included
+in the order they appear on the command line.
+@item -imacros @var{file}
+@opindex imacros
+Exactly like @option{-include}, except that any output produced by
+scanning @var{file} is thrown away.  Macros it defines remain defined.
+This allows you to acquire all the macros from a header without also
+processing its declarations.
+All files specified by @option{-imacros} are processed before all files
+specified by @option{-include}.
 @item -undef
 @opindex undef
 Do not predefine any system-specific or GCC-specific macros.  The
 standard predefined macros remain defined.
 @ifset cppmanual
 @xref{Standard Predefined Macros}.
 @end ifset
-@item -I @var{dir}
+@item -pthread
-@opindex I
+@opindex pthread
-Add the directory @var{dir} to the list of directories to be searched
+Define additional macros required for using the POSIX threads library.
-for header files.
+You should use this option consistently for both compilation and linking.
-@ifset cppmanual
+This option is supported on GNU/Linux targets, most other Unix derivatives,
-@xref{Search Path}.
+and also on x86 Cygwin and MinGW targets.
-@end ifset
-Directories named by @option{-I} are searched before the standard
-system include directories.  If the directory @var{dir} is a standard
-system include directory, the option is ignored to ensure that the
-default search order for system directories and the special treatment
-of system headers are not defeated
-@ifset cppmanual
-(@pxref{System Headers})
-@end ifset
-.
-If @var{dir} begins with @code{=}, then the @code{=} will be replaced
-by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
-@item -o @var{file}
-@opindex o
-Write output to @var{file}.  This is the same as specifying @var{file}
-as the second non-option argument to @command{cpp}.  @command{gcc} has a
-different interpretation of a second non-option argument, so you must
-use @option{-o} to specify the output file.
-@item -Wall
-@opindex Wall
-Turns on all optional warnings which are desirable for normal code.
-At present this is @option{-Wcomment}, @option{-Wtrigraphs},
-@option{-Wmultichar} and a warning about integer promotion causing a
-change of sign in @code{#if} expressions.  Note that many of the
-preprocessor's warnings are on by default and have no options to
-control them.
-@item -Wcomment
-@itemx -Wcomments
-@opindex Wcomment
-@opindex Wcomments
-Warn whenever a comment-start sequence @samp{/*} appears in a @samp{/*}
-comment, or whenever a backslash-newline appears in a @samp{//} comment.
-(Both forms have the same effect.)
-@item -Wtrigraphs
-@opindex Wtrigraphs
-@anchor{Wtrigraphs}
-Most trigraphs in comments cannot affect the meaning of the program.
-However, a trigraph that would form an escaped newline (@samp{??/} at
-the end of a line) can, by changing where the comment begins or ends.
-Therefore, only trigraphs that would form escaped newlines produce
-warnings inside a comment.
-This option is implied by @option{-Wall}.  If @option{-Wall} is not
-given, this option is still enabled unless trigraphs are enabled.  To
-get trigraph conversion without warnings, but get the other
-@option{-Wall} warnings, use @samp{-trigraphs -Wall -Wno-trigraphs}.
-@item -Wtraditional
-@opindex Wtraditional
-Warn about certain constructs that behave differently in traditional and
-ISO C@.  Also warn about ISO C constructs that have no traditional C
-equivalent, and problematic constructs which should be avoided.
-@ifset cppmanual
-@xref{Traditional Mode}.
-@end ifset
-@item -Wundef
-@opindex Wundef
-Warn whenever an identifier which is not a macro is encountered in an
-@samp{#if} directive, outside of @samp{defined}.  Such identifiers are
-replaced with zero.
-@item -Wunused-macros
-@opindex Wunused-macros
-Warn about macros defined in the main file that are unused.  A macro
-is @dfn{used} if it is expanded or tested for existence at least once.
-The preprocessor will also warn if the macro has not been used at the
-time it is redefined or undefined.
-Built-in macros, macros defined on the command line, and macros
-defined in include files are not warned about.
-@emph{Note:} If a macro is actually used, but only used in skipped
-conditional blocks, then CPP will report it as unused.  To avoid the
-warning in such a case, you might improve the scope of the macro's
-definition by, for example, moving it into the first skipped block.
-Alternatively, you could provide a dummy use with something like:
-@smallexample
-#if defined the_macro_causing_the_warning
-#endif
-@end smallexample
-@item -Wendif-labels
-@opindex Wendif-labels
-Warn whenever an @samp{#else} or an @samp{#endif} are followed by text.
-This usually happens in code of the form
-@smallexample
-#if FOO
-@dots{}
-#else FOO
-@dots{}
-#endif FOO
-@end smallexample
-@noindent
-The second and third @code{FOO} should be in comments, but often are not
-in older programs.  This warning is on by default.
-@item -Werror
-@opindex Werror
-Make all warnings into hard errors.  Source code which triggers warnings
-will be rejected.
-@item -Wsystem-headers
-@opindex Wsystem-headers
-Issue warnings for code in system headers.  These are normally unhelpful
-in finding bugs in your own code, therefore suppressed.  If you are
-responsible for the system library, you may want to see them.
-@item -w
-@opindex w
-Suppress all warnings, including those which GNU CPP issues by default.
-@item -pedantic
-@opindex pedantic
-Issue all the mandatory diagnostics listed in the C standard.  Some of
-them are left out by default, since they trigger frequently on harmless
-code.
-@item -pedantic-errors
-@opindex pedantic-errors
-Issue all the mandatory diagnostics, and make all mandatory diagnostics
-into errors.  This includes mandatory diagnostics that GCC issues
-without @samp{-pedantic} but treats as warnings.
 @item -M
 @opindex M
 @cindex @command{make}
 @cindex dependencies, @command{make}
 Instead of outputting the result of preprocessing, output a rule
 suitable for @command{make} describing the dependencies of the main
 source file.  The preprocessor outputs one @command{make} rule containing
 the object file name for that source file, a colon, and the names of all
 the included files, including those coming from @option{-include} or
-@option{-imacros} command line options.
+@option{-imacros} command-line options.
 Unless specified explicitly (with @option{-MT} or @option{-MQ}), the
 object file name consists of the name of the source file with any
 suffix replaced with object file suffix and with any leading directory
 parts removed.  If there are many included files then the rule is
 This option does not suppress the preprocessor's debug output, such as
 @option{-dM}.  To avoid mixing such debug output with the dependency
 rules you should explicitly specify the dependency output file with
 @option{-MF}, or use an environment variable like
 @env{DEPENDENCIES_OUTPUT} (@pxref{Environment Variables}).  Debug output
-will still be sent to the regular output stream as normal.
+is still sent to the regular output stream as normal.
 Passing @option{-M} to the driver implies @option{-E}, and suppresses
 warnings with an implicit @option{-w}.
 @item -MM
 system header directories, nor header files that are included,
 directly or indirectly, from such a header.
 This implies that the choice of angle brackets or double quotes in an
 @samp{#include} directive does not in itself determine whether that
-header will appear in @option{-MM} dependency output.  This is a
+header appears in @option{-MM} dependency output.
-slight change in semantics from GCC versions 3.0 and earlier.
 @anchor{dashMF}
 @item -MF @var{file}
 @opindex MF
 When used with @option{-M} or @option{-MM}, specifies a
 file to write the dependencies to.  If no @option{-MF} switch is given
-the preprocessor sends the rules to the same place it would have sent
+the preprocessor sends the rules to the same place it would send
 preprocessed output.
 When used with the driver options @option{-MD} or @option{-MMD},
 @option{-MF} overrides the default dependency output file.
+If @var{file} is @file{-}, then the dependencies are written to @file{stdout}.
 @item -MG
 @opindex MG
 In conjunction with an option such as @option{-M} requesting
 dependency generation, @option{-MG} assumes missing header files are
 Change the target of the rule emitted by dependency generation.  By
 default CPP takes the name of the main input file, deletes any
 directory components and any file suffix such as @samp{.c}, and
 appends the platform's usual object suffix.  The result is the target.
-An @option{-MT} option will set the target to be exactly the string you
+An @option{-MT} option sets the target to be exactly the string you
 specify.  If you want multiple targets, you can specify them as a single
 argument to @option{-MT}, or use multiple @option{-MT} options.
 For example, @option{@w{-MT '$(objpfx)foo.o'}} might give
 @item -MMD
 @opindex MMD
 Like @option{-MD} except mention only user header files, not system
 header files.
-@ifclear cppmanual
-@item -fpch-deps
-@opindex fpch-deps
-When using precompiled headers (@pxref{Precompiled Headers}), this flag
-will cause the dependency-output flags to also list the files from the
-precompiled header's dependencies.  If not specified only the
-precompiled header would be listed and not the files that were used to
-create it because those files are not consulted when a precompiled
-header is used.
-@item -fpch-preprocess
-@opindex fpch-preprocess
-This option allows use of a precompiled header (@pxref{Precompiled
-Headers}) together with @option{-E}.  It inserts a special @code{#pragma},
-@code{#pragma GCC pch_preprocess "@var{filename}"} in the output to mark
-the place where the precompiled header was found, and its @var{filename}.
-When @option{-fpreprocessed} is in use, GCC recognizes this @code{#pragma}
-and loads the PCH@.
-This option is off by default, because the resulting preprocessed output
-is only really suitable as input to GCC@.  It is switched on by
-@option{-save-temps}.
-You should not write this @code{#pragma} in your own code, but it is
-safe to edit the filename if the PCH file is available in a different
-location.  The filename may be absolute or it may be relative to GCC's
-current directory.
-@end ifclear
-@item -x c
-@itemx -x c++
-@itemx -x objective-c
-@itemx -x assembler-with-cpp
-@opindex x
-Specify the source language: C, C++, Objective-C, or assembly.  This has
-nothing to do with standards conformance or extensions; it merely
-selects which base syntax to expect.  If you give none of these options,
-cpp will deduce the language from the extension of the source file:
-@samp{.c}, @samp{.cc}, @samp{.m}, or @samp{.S}.  Some other common
-extensions for C++ and assembly are also recognized.  If cpp does not
-recognize the extension, it will treat the file as C; this is the most
-generic mode.
-@emph{Note:} Previous versions of cpp accepted a @option{-lang} option
-which selected both the language and the standards conformance level.
-This option has been removed, because it conflicts with the @option{-l}
-option.
-@item -std=@var{standard}
-@itemx -ansi
-@opindex ansi
-@opindex std=
-Specify the standard to which the code should conform.  Currently CPP
-knows about C and C++ standards; others may be added in the future.
-@var{standard}
-may be one of:
-@table @code
-@item c90
-@itemx c89
-@itemx iso9899:1990
-The ISO C standard from 1990.  @samp{c90} is the customary shorthand for
-this version of the standard.
-The @option{-ansi} option is equivalent to @option{-std=c90}.
-@item iso9899:199409
-The 1990 C standard, as amended in 1994.
-@item iso9899:1999
-@itemx c99
-@itemx iso9899:199x
-@itemx c9x
-The revised ISO C standard, published in December 1999.  Before
-publication, this was known as C9X@.
-@item c1x
-The next version of the ISO C standard, still under development.
-@item gnu90
-@itemx gnu89
-The 1990 C standard plus GNU extensions.  This is the default.
-@item gnu99
-@itemx gnu9x
-The 1999 C standard plus GNU extensions.
-@item gnu1x
-The next version of the ISO C standard, still under development, plus
-GNU extensions.
-@item c++98
-The 1998 ISO C++ standard plus amendments.
-@item gnu++98
-The same as @option{-std=c++98} plus GNU extensions.  This is the
-default for C++ code.
-@end table
-@item -I-
-@opindex I-
-Split the include path.  Any directories specified with @option{-I}
-options before @option{-I-} are searched only for headers requested with
-@code{@w{#include "@var{file}"}}; they are not searched for
-@code{@w{#include <@var{file}>}}.  If additional directories are
-specified with @option{-I} options after the @option{-I-}, those
-directories are searched for all @samp{#include} directives.
-In addition, @option{-I-} inhibits the use of the directory of the current
-file directory as the first search directory for @code{@w{#include
-"@var{file}"}}.
-@ifset cppmanual
-@xref{Search Path}.
-@end ifset
-This option has been deprecated.
-@item -nostdinc
-@opindex nostdinc
-Do not search the standard system directories for header files.
-Only the directories you have specified with @option{-I} options
-(and the directory of the current file, if appropriate) are searched.
-@item -nostdinc++
-@opindex 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 the C++ library.)
-@item -include @var{file}
-@opindex include
-Process @var{file} as if @code{#include "file"} appeared as the first
-line of the primary source file.  However, the first directory searched
-for @var{file} is the preprocessor's working directory @emph{instead of}
-the directory containing the main source file.  If not found there, it
-is searched for in the remainder of the @code{#include "@dots{}"} search
-chain as normal.
-If multiple @option{-include} options are given, the files are included
-in the order they appear on the command line.
-@item -imacros @var{file}
-@opindex imacros
-Exactly like @option{-include}, except that any output produced by
-scanning @var{file} is thrown away.  Macros it defines remain defined.
-This allows you to acquire all the macros from a header without also
-processing its declarations.
-All files specified by @option{-imacros} are processed before all files
-specified by @option{-include}.
-@item -idirafter @var{dir}
-@opindex idirafter
-Search @var{dir} for header files, but do it @emph{after} all
-directories specified with @option{-I} and the standard system directories
-have been exhausted.  @var{dir} is treated as a system include directory.
-If @var{dir} begins with @code{=}, then the @code{=} will be replaced
-by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
-@item -iprefix @var{prefix}
-@opindex iprefix
-Specify @var{prefix} as the prefix for subsequent @option{-iwithprefix}
-options.  If the prefix represents a directory, you should include the
-final @samp{/}.
-@item -iwithprefix @var{dir}
-@itemx -iwithprefixbefore @var{dir}
-@opindex iwithprefix
-@opindex iwithprefixbefore
-Append @var{dir} to the prefix specified previously with
-@option{-iprefix}, and add the resulting directory to the include search
-path.  @option{-iwithprefixbefore} puts it in the same place @option{-I}
-would; @option{-iwithprefix} puts it where @option{-idirafter} would.
-@item -isysroot @var{dir}
-@opindex isysroot
-This option is like the @option{--sysroot} option, but applies only to
-header files (except for Darwin targets, where it applies to both header
-files and libraries).  See the @option{--sysroot} option for more
-information.
-@item -imultilib @var{dir}
-@opindex imultilib
-Use @var{dir} as a subdirectory of the directory containing
-target-specific C++ headers.
-@item -isystem @var{dir}
-@opindex isystem
-Search @var{dir} for header files, after all directories specified by
-@option{-I} but before the standard system directories.  Mark it
-as a system directory, so that it gets the same special treatment as
-is applied to the standard system directories.
-@ifset cppmanual
-@xref{System Headers}.
-@end ifset
-If @var{dir} begins with @code{=}, then the @code{=} will be replaced
-by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
-@item -iquote @var{dir}
-@opindex iquote
-Search @var{dir} only for header files requested with
-@code{@w{#include "@var{file}"}}; they are not searched for
-@code{@w{#include <@var{file}>}}, before all directories specified by
-@option{-I} and before the standard system directories.
-@ifset cppmanual
-@xref{Search Path}.
-@end ifset
-If @var{dir} begins with @code{=}, then the @code{=} will be replaced
-by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
-@item -fdirectives-only
-@opindex fdirectives-only
-When preprocessing, handle directives, but do not expand macros.
-The option's behavior depends on the @option{-E} and @option{-fpreprocessed}
-options.
-With @option{-E}, preprocessing is limited to the handling of directives
-such as @code{#define}, @code{#ifdef}, and @code{#error}.  Other
-preprocessor operations, such as macro expansion and trigraph
-conversion are not performed.  In addition, the @option{-dD} option is
-implicitly enabled.
-With @option{-fpreprocessed}, predefinition of command line and most
-builtin macros is disabled.  Macros such as @code{__LINE__}, which are
-contextually dependent, are handled normally.  This enables compilation of
-files previously preprocessed with @code{-E -fdirectives-only}.
-With both @option{-E} and @option{-fpreprocessed}, the rules for
-@option{-fpreprocessed} take precedence.  This enables full preprocessing of
-files previously preprocessed with @code{-E -fdirectives-only}.
-@item -fdollars-in-identifiers
-@opindex fdollars-in-identifiers
-@anchor{fdollars-in-identifiers}
-Accept @samp{$} in identifiers.
-@ifset cppmanual
-@xref{Identifier characters}.
-@end ifset
-@item -fextended-identifiers
-@opindex fextended-identifiers
-Accept universal character names in identifiers.  This option is
-experimental; in a future version of GCC, it will be enabled by
-default for C99 and C++.
 @item -fpreprocessed
 @opindex fpreprocessed
 Indicate to the preprocessor that the input file has already been
 preprocessed.  This suppresses things like macro expansion, trigraph
 @option{-fpreprocessed} is implicit if the input file has one of the
 extensions @samp{.i}, @samp{.ii} or @samp{.mi}.  These are the
 extensions that GCC uses for preprocessed files created by
 @option{-save-temps}.
+@item -fdirectives-only
+@opindex fdirectives-only
+When preprocessing, handle directives, but do not expand macros.
+The option's behavior depends on the @option{-E} and @option{-fpreprocessed}
+options.
+With @option{-E}, preprocessing is limited to the handling of directives
+such as @code{#define}, @code{#ifdef}, and @code{#error}.  Other
+preprocessor operations, such as macro expansion and trigraph
+conversion are not performed.  In addition, the @option{-dD} option is
+implicitly enabled.
+With @option{-fpreprocessed}, predefinition of command line and most
+builtin macros is disabled.  Macros such as @code{__LINE__}, which are
+contextually dependent, are handled normally.  This enables compilation of
+files previously preprocessed with @code{-E -fdirectives-only}.
+With both @option{-E} and @option{-fpreprocessed}, the rules for
+@option{-fpreprocessed} take precedence.  This enables full preprocessing of
+files previously preprocessed with @code{-E -fdirectives-only}.
+@item -fdollars-in-identifiers
+@opindex fdollars-in-identifiers
+@anchor{fdollars-in-identifiers}
+Accept @samp{$} in identifiers.
+@ifset cppmanual
+@xref{Identifier characters}.
+@end ifset
+@item -fextended-identifiers
+@opindex fextended-identifiers
+Accept universal character names in identifiers.  This option is
+enabled by default for C99 (and later C standard versions) and C++.
+@item -fno-canonical-system-headers
+@opindex fno-canonical-system-headers
+When preprocessing, do not shorten system header paths with canonicalization.
 @item -ftabstop=@var{width}
 @opindex ftabstop
 Set the distance between tab stops.  This helps the preprocessor report
 correct column numbers in warnings or errors, even if tabs appear on the
 line.  If the value is less than 1 or greater than 100, the option is
 ignored.  The default is 8.
+@item -ftrack-macro-expansion@r{[}=@var{level}@r{]}
+@opindex ftrack-macro-expansion
+Track locations of tokens across macro expansions. This allows the
+compiler to emit diagnostic about the current macro expansion stack
+when a compilation error occurs in a macro expansion. Using this
+option makes the preprocessor and the compiler consume more
+memory. The @var{level} parameter can be used to choose the level of
+precision of token location tracking thus decreasing the memory
+consumption if necessary. Value @samp{0} of @var{level} de-activates
+this option. Value @samp{1} tracks tokens locations in a
+degraded mode for the sake of minimal memory overhead. In this mode
+all tokens resulting from the expansion of an argument of a
+function-like macro have the same location. Value @samp{2} tracks
+tokens locations completely. This value is the most memory hungry.
+When this option is given no argument, the default parameter value is
+@samp{2}.
+Note that @code{-ftrack-macro-expansion=2} is activated by default.
 @item -fexec-charset=@var{charset}
 @opindex fexec-charset
 @cindex character set, execution
 Set the execution character set, used for string and character
 @cindex character set, input
 Set the input character set, used for translation from the character
 set of the input file to the source character set used by GCC@.  If the
 locale does not specify, or GCC cannot get this information from the
 locale, the default is UTF-8.  This can be overridden by either the locale
-or this command line option.  Currently the command line option takes
+or this command-line option.  Currently the command-line option takes
 precedence if there's a conflict.  @var{charset} can be any encoding
 supported by the system's @code{iconv} library routine.
+@ifclear cppmanual
+@item -fpch-deps
+@opindex fpch-deps
+When using precompiled headers (@pxref{Precompiled Headers}), this flag
+causes the dependency-output flags to also list the files from the
+precompiled header's dependencies.  If not specified, only the
+precompiled header are listed and not the files that were used to
+create it, because those files are not consulted when a precompiled
+header is used.
+@item -fpch-preprocess
+@opindex fpch-preprocess
+This option allows use of a precompiled header (@pxref{Precompiled
+Headers}) together with @option{-E}.  It inserts a special @code{#pragma},
+@code{#pragma GCC pch_preprocess "@var{filename}"} in the output to mark
+the place where the precompiled header was found, and its @var{filename}.
+When @option{-fpreprocessed} is in use, GCC recognizes this @code{#pragma}
+and loads the PCH@.
+This option is off by default, because the resulting preprocessed output
+is only really suitable as input to GCC@.  It is switched on by
+@option{-save-temps}.
+You should not write this @code{#pragma} in your own code, but it is
+safe to edit the filename if the PCH file is available in a different
+location.  The filename may be absolute or it may be relative to GCC's
+current directory.
+@end ifclear
 @item -fworking-directory
 @opindex fworking-directory
 @opindex fno-working-directory
-Enable generation of linemarkers in the preprocessor output that will
+Enable generation of linemarkers in the preprocessor output that
 let the compiler know the current working directory at the time of
-preprocessing.  When this option is enabled, the preprocessor will
+preprocessing.  When this option is enabled, the preprocessor
-emit, after the initial linemarker, a second linemarker with the
+emits, after the initial linemarker, a second linemarker with the
-current working directory followed by two slashes.  GCC will use this
+current working directory followed by two slashes.  GCC uses this
 directory, when it's present in the preprocessed input, as the
 directory emitted as the current working directory in some debugging
 information formats.  This option is implicitly enabled if debugging
 information is enabled, but this can be inhibited with the negated
 form @option{-fno-working-directory}.  If the @option{-P} flag is
 present in the command line, this option has no effect, since no
 @code{#line} directives are emitted whatsoever.
-@item -fno-show-column
-@opindex fno-show-column
-Do not print column numbers in diagnostics.  This may be necessary if
-diagnostics are being scanned by a program that does not understand the
-column numbers, such as @command{dejagnu}.
 @item -A @var{predicate}=@var{answer}
 @opindex A
 Make an assertion with the predicate @var{predicate} and answer
 @var{answer}.  This form is preferred to the older form @option{-A
 @item -A -@var{predicate}=@var{answer}
 Cancel an assertion with the predicate @var{predicate} and answer
 @var{answer}.
-@item -dCHARS
+@item -C
-@var{CHARS} is a sequence of one or more of the following characters,
+@opindex C
-and must not be preceded by a space.  Other characters are interpreted
+Do not discard comments.  All comments are passed through to the output
-by the compiler proper, or reserved for future versions of GCC, and so
+file, except for comments in processed directives, which are deleted
-are silently ignored.  If you specify characters whose behavior
+along with the directive.
-conflicts, the result is undefined.
+You should be prepared for side effects when using @option{-C}; it
-@table @samp
+causes the preprocessor to treat comments as tokens in their own right.
-@item M
+For example, comments appearing at the start of what would be a
-@opindex dM
+directive line have the effect of turning that line into an ordinary
-Instead of the normal output, generate a list of @samp{#define}
+source line, since the first token on the line is no longer a @samp{#}.
-directives for all the macros defined during the execution of the
-preprocessor, including predefined macros.  This gives you a way of
+@item -CC
-finding out what is predefined in your version of the preprocessor.
+@opindex CC
-Assuming you have no file @file{foo.h}, the command
+Do not discard comments, including during macro expansion.  This is
+like @option{-C}, except that comments contained within macros are
-@smallexample
+also passed through to the output file where the macro is expanded.
-touch foo.h; cpp -dM foo.h
-@end smallexample
+In addition to the side-effects of the @option{-C} option, the
+@option{-CC} option causes all C++-style comments inside a macro
-@noindent
+to be converted to C-style comments.  This is to prevent later use
-will show all the predefined macros.
+of that macro from inadvertently commenting out the remainder of
+the source line.
-If you use @option{-dM} without the @option{-E} option, @option{-dM} is
-interpreted as a synonym for @option{-fdump-rtl-mach}.
+The @option{-CC} option is generally used to support lint comments.
-@xref{Debugging Options, , ,gcc}.
-@item D
-@opindex dD
-Like @samp{M} except in two respects: it does @emph{not} include the
-predefined macros, and it outputs @emph{both} the @samp{#define}
-directives and the result of preprocessing.  Both kinds of output go to
-the standard output file.
-@item N
-@opindex dN
-Like @samp{D}, but emit only the macro names, not their expansions.
-@item I
-@opindex dI
-Output @samp{#include} directives in addition to the result of
-preprocessing.
-@item U
-@opindex dU
-Like @samp{D} except that only macros that are expanded, or whose
-definedness is tested in preprocessor directives, are output; the
-output is delayed until the use or test of the macro; and
-@samp{#undef} directives are also output for macros tested but
-undefined at the time.
-@end table
 @item -P
 @opindex P
 Inhibit generation of linemarkers in the output from the preprocessor.
 This might be useful when running the preprocessor on something that is
 linemarkers.
 @ifset cppmanual
 @xref{Preprocessor Output}.
 @end ifset
-@item -C
+@cindex traditional C language
-@opindex C
+@cindex C language, traditional
-Do not discard comments.  All comments are passed through to the output
+@item -traditional
-file, except for comments in processed directives, which are deleted
+@itemx -traditional-cpp
-along with the directive.
-You should be prepared for side effects when using @option{-C}; it
-causes the preprocessor to treat comments as tokens in their own right.
-For example, comments appearing at the start of what would be a
-directive line have the effect of turning that line into an ordinary
-source line, since the first token on the line is no longer a @samp{#}.
-@item -CC
-Do not discard comments, including during macro expansion.  This is
-like @option{-C}, except that comments contained within macros are
-also passed through to the output file where the macro is expanded.
-In addition to the side-effects of the @option{-C} option, the
-@option{-CC} option causes all C++-style comments inside a macro
-to be converted to C-style comments.  This is to prevent later use
-of that macro from inadvertently commenting out the remainder of
-the source line.
-The @option{-CC} option is generally used to support lint comments.
-@item -traditional-cpp
 @opindex traditional-cpp
-Try to imitate the behavior of old-fashioned C preprocessors, as
+@opindex traditional
+Try to imitate the behavior of pre-standard C preprocessors, as
 opposed to ISO C preprocessors.
 @ifset cppmanual
 @xref{Traditional Mode}.
 @end ifset
+@ifclear cppmanual
+See the GNU CPP manual for details.
+@end ifclear
+Note that GCC does not otherwise attempt to emulate a pre-standard
+C compiler, and these options are only supported with the @option{-E}
+switch, or when invoking CPP explicitly.
 @item -trigraphs
 @opindex trigraphs
-Process trigraph sequences.
+Support ISO C trigraphs.
+These are three-character sequences, all starting with @samp{??}, that
+are defined by ISO C to stand for single characters.  For example,
+@samp{??/} stands for @samp{\}, so @samp{'??/n'} is a character
+constant for a newline.
 @ifset cppmanual
 @xref{Initial processing}.
 @end ifset
 @ifclear cppmanual
-These are three-character sequences, all starting with @samp{??}, that
-are defined by ISO C to stand for single characters.  For example,
-@samp{??/} stands for @samp{\}, so @samp{'??/n'} is a character
-constant for a newline.  By default, GCC ignores trigraphs, but in
-standard-conforming modes it converts them.  See the @option{-std} and
-@option{-ansi} options.
 The nine trigraphs and their replacements are
 @smallexample
 Trigraph:       ??(  ??)  ??<  ??>  ??=  ??/  ??'  ??!  ??-
 Replacement:      [    ]    @{    @}    #    \    ^    |    ~
 @end smallexample
 @end ifclear
+By default, GCC ignores trigraphs, but in
+standard-conforming modes it converts them.  See the @option{-std} and
+@option{-ansi} options.
 @item -remap
 @opindex remap
 Enable special code to work around file systems which only permit very
 short file names, such as MS-DOS@.
-@itemx --help
-@itemx --target-help
-@opindex help
-@opindex target-help
-Print text describing all the command line options instead of
-preprocessing anything.
-@item -v
-@opindex v
-Verbose mode.  Print out GNU CPP's version number at the beginning of
-execution, and report the final form of the include path.
 @item -H
 @opindex H
 Print the name of each header file used, in addition to other normal
 activities.  Each name is indented to show how deep in the
 @samp{#include} stack it is.  Precompiled header files are also
 printed, even if they are found to be invalid; an invalid precompiled
 header file is printed with @samp{...x} and a valid one with @samp{...!} .
-@item -version
+@item -d@var{letters}
-@itemx --version
+@opindex d
-@opindex version
+Says to make debugging dumps during compilation as specified by
-Print out GNU CPP's version number.  With one dash, proceed to
+@var{letters}.  The flags documented here are those relevant to the
-preprocess as normal.  With two dashes, exit immediately.
+preprocessor.  Other @var{letters} are interpreted
+by the compiler proper, or reserved for future versions of GCC, and so
+are silently ignored.  If you specify @var{letters} whose behavior
+conflicts, the result is undefined.
+@ifclear cppmanual
+@xref{Developer Options}, for more information.
+@end ifclear
+@table @gcctabopt
+@item -dM
+@opindex dM
+Instead of the normal output, generate a list of @samp{#define}
+directives for all the macros defined during the execution of the
+preprocessor, including predefined macros.  This gives you a way of
+finding out what is predefined in your version of the preprocessor.
+Assuming you have no file @file{foo.h}, the command
+@smallexample
+touch foo.h; cpp -dM foo.h
+@end smallexample
+@noindent
+shows all the predefined macros.
+@ifclear cppmanual
+If you use @option{-dM} without the @option{-E} option, @option{-dM} is
+interpreted as a synonym for @option{-fdump-rtl-mach}.
+@xref{Developer Options, , ,gcc}.
+@end ifclear
+@item -dD
+@opindex dD
+Like @option{-dM} except in two respects: it does @emph{not} include the
+predefined macros, and it outputs @emph{both} the @samp{#define}
+directives and the result of preprocessing.  Both kinds of output go to
+the standard output file.
+@item -dN
+@opindex dN
+Like @option{-dD}, but emit only the macro names, not their expansions.
+@item -dI
+@opindex dI
+Output @samp{#include} directives in addition to the result of
+preprocessing.
+@item -dU
+@opindex dU
+Like @option{-dD} except that only macros that are expanded, or whose
+definedness is tested in preprocessor directives, are output; the
+output is delayed until the use or test of the macro; and
+@samp{#undef} directives are also output for macros tested but
+undefined at the time.
 @end table
+@item -fdebug-cpp
+@opindex fdebug-cpp
+This option is only useful for debugging GCC.  When used from CPP or with
+@option{-E}, it dumps debugging information about location maps.  Every
+token in the output is preceded by the dump of the map its location
+belongs to.
+When used from GCC without @option{-E}, this option has no effect.

Mercurial > hg > CbC > CbC_gcc

comparison gcc/doc/cppopts.texi @ 111:04ced10e8804