c-pragma.c (handle_pragma_diagnostic): New.

* c-pragma.c (handle_pragma_diagnostic): New.
(init_pragma): Register it.
* doc/extend.texi: Document it.

* diagnostic.def: Add DK_UNSPECIFIED and DK_IGNORED.
* diagnostic.h (diagnostic_classify_diagnostic): Declare.
(diagnostic_context): Add classify_diagnostic[].
* diagnostic.c (diagnostic_count_diagnostic): Don't count warnings
as errors if they're overridden to DK_WARNING.
(diagnostic_initialize): Initialize classify_diagnostic[].
(diagnostic_set_kind_override): New.
(diagnostic_report_diagnostic): Check for kind changes.
* opts.c (common_handle_option): Take lang_mask.  Update callers.
Handle OPT_Werror_.
* common.opt (Werror=): New.
* doc/invoke.texi: Document -Werror=*

From-SVN: r109907

2 files changed, 65 insertions, 3 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 0c2f39c..9d5a8f6 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -1,5 +1,5 @@
 @c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1996, 1998, 1999, 2000,
-@c 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+@c 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 
 @c This is part of the GCC manual.
 @c For copying conditions, see the file gcc.texi.
@@ -9290,6 +9290,7 @@ for further explanation.
 * Symbol-Renaming Pragmas::
 * Structure-Packing Pragmas::
 * Weak Pragmas::
+* Diagnostic Pragmas::
 @end menu
 
 @node ARM Pragmas
@@ -9530,6 +9531,51 @@ It is an error if @var{symbol2} is not defined in the current
 translation unit.
 @end table
 
+@node Diagnostic Pragmas
+@subsection Diagnostic Pragmas
+
+GCC allows the user to selectively enable or disable certain types of
+diagnostics, and change the kind of the diagnostic.  For example, a
+project's policy might require that all sources compile with
+@option{-Werror} but certain files might have exceptions allowing
+specific types of warnings.  Or, a project might selectively enable
+diagnostics and treat them as errors depending on which preprocessor
+macros are defined.
+
+@table @code
+@item #pragma GCC diagnostic @var{kind} @var{option}
+@cindex pragma, diagnostic
+
+Modifies the disposition of a diagnostic.  Note that not all
+diagnostics are modifyiable; at the moment only warnings (normally
+controlled by @samp{-W...}) can be controlled, and not all of them.
+Use @option{-fdiagnostics-show-option} to determine which diagnostics
+are controllable and which option controls them.
+
+@var{kind} is @samp{error} to treat this diagnostic as an error,
+@samp{warning} to treat it like a warning (even if @option{-Werror} is
+in effect), or @samp{ignored} if the diagnostic is to be ignored.
+@var{option} is a double quoted string which matches the command line
+option.
+
+@example
+#pragma GCC diagnostic warning "-Wformat"
+#pragma GCC diagnostic error "-Walways-true"
+#pragma GCC diagnostic ignored "-Walways-true"
+@end example
+
+Note that these pragmas override any command line options.  Also,
+while it is syntactically valid to put these pragmas anywhere in your
+sources, the only supported location for them is before any data or
+functions are defined.  Doing otherwise may result in unpredictable
+results depending on how the optimizer manages your sources.  If the
+same option is listed multiple times, the last one specified is the
+one that is in effect.  This pragma is not intended to be a general
+purpose replacement for command line options, but for implementing
+strict control over project policies.
+
+@end table
+
 @node Unnamed Fields
 @section Unnamed struct/union fields within structs/unions
 @cindex struct
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 629e4a9..924c121 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1,5 +1,5 @@
 @c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-@c 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+@c 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 @c This is part of the GCC manual.
 @c For copying conditions, see the file gcc.texi.
 
@@ -226,7 +226,7 @@ Objective-C and Objective-C++ Dialects}.
 -Wc++-compat -Wcast-align  -Wcast-qual  -Wchar-subscripts  -Wcomment @gol
 -Wconversion  -Wno-deprecated-declarations @gol
 -Wdisabled-optimization  -Wno-div-by-zero  -Wno-endif-labels @gol
--Werror  -Werror-implicit-function-declaration @gol
+-Werror  -Werror-* -Werror-implicit-function-declaration @gol
 -Wfatal-errors  -Wfloat-equal  -Wformat  -Wformat=2 @gol
 -Wno-format-extra-args -Wformat-nonliteral @gol
 -Wformat-security  -Wformat-y2k @gol
@@ -3411,6 +3411,22 @@ This option is only supported for C and Objective-C@.
 @opindex Werror
 Make all warnings into errors.
 
+@item -Werror=
+@opindex Werror=
+Make the specified warning into an errors.  The specifier for a
+warning is appended, for example @option{-Werror=switch} turns the
+warnings controlled by @option{-Wswitch} into errors.  This switch
+takes a negative form, to be used to negate @option{-Werror} for
+specific warnings, for example @option{-Wno-error=switch} makes
+@option{-Wswitch} warnings not be errors, even when @option{-Werror}
+is in effect.  You can use the @option{-fdiagnostics-show-option}
+option to have each controllable warning amended with the option which
+controls it, to determine what to use with this option.
+
+Note that specifying @option{-Werror=}@var{foo} automatically implies
+@option{-W}@var{foo}.  However, @option{-Wno-error=}@var{foo} does not
+imply anything.
+
 @item -Wstack-protector
 @opindex Wstack-protector
 This option is only active when @option{-fstack-protector} is active.  It