+2003-01-24 Phil Edwards <pme@gcc.gnu.org>
+
+ Rename -W to -Wextra.
+ * c-decl.c: Update comments.
+ * c-typeck.c: Likewise.
+ * flags.h: Likewise.
+ * function.c: Likewise.
+ * stmt.c: Likewise.
+ * toplev.c: Update comments.
+ (W_options): Add 'extra'.
+ (display_help): Remove '-W'.
+ (decode_W_option): Special warn_uninitialized treatment in the case
+ of -Wextra.
+ * doc/invoke.texi: Update with new entries.
+
2003-01-23 Richard Henderson <rth@redhat.com>
* ifcvt.c (noce_process_if_block): Re-add check vs X being changed
{
/* Type qualifiers on a function return type are normally
permitted by the standard but have no effect, so give a
- warning at -W. Qualifiers on a void return type have
+ warning at -Wextra. Qualifiers on a void return type have
meaning as a GNU extension, and are banned on function
definitions in ISO C. FIXME: strictly we shouldn't
pedwarn for qualified void return types except on function
if (nested_p)
ggc_pop_context ();
- /* With just -W, complain only if function returns both with
+ /* With just -Wextra, complain only if function returns both with
and without a value. */
if (extra_warnings
&& current_function_returns_value
if (! TREE_SIDE_EFFECTS (TREE_VALUE (list)))
{
/* The left-hand operand of a comma expression is like an expression
- statement: with -W or -Wunused, we should warn if it doesn't have
+ statement: with -Wextra or -Wunused, we should warn if it doesn't have
any side-effects, unless it was explicitly cast to (void). */
if ((extra_warnings || warn_unused_value)
&& ! (TREE_CODE (TREE_VALUE (list)) == CONVERT_EXPR
@xref{Warning Options,,Options to Request or Suppress Warnings}.
@gccoptlist{
-fsyntax-only -pedantic -pedantic-errors @gol
--w -W -Wall -Waggregate-return @gol
+-w -Wextra -Wall -Waggregate-return @gol
-Wcast-align -Wcast-qual -Wchar-subscripts -Wcomment @gol
-Wconversion -Wno-deprecated-declarations @gol
-Wdisabled-optimization -Wno-div-by-zero -Werror @gol
understood by @command{gcc}. If the @option{-v} option is also specified
then @option{--help} will also be passed on to the various processes
invoked by @command{gcc}, so that they can display the command line options
-they accept. If the @option{-W} option is also specified then command
+they accept. If the @option{-Wextra} option is also specified then command
line options which have no documentation associated with them will also
be displayed.
All the above @option{-Wunused} options combined.
In order to get a warning about an unused function parameter, you must
-either specify @samp{-W -Wunused} or separately specify
-@option{-Wunused-parameter}.
+either specify @samp{-Wextra -Wunused} (note that @samp{-Wall} implies
+@samp{-Wunused}), or separately specify @option{-Wunused-parameter}.
@item -Wuninitialized
@opindex Wuninitialized
the warning.
@table @gcctabopt
-@item -W
+@item -Wextra
@opindex W
-Print extra warning messages for these events:
+@opindex Wextra
+(This option used to be called @option{-W}. The older name is still
+supported, but the newer name is more descriptive.) Print extra warning
+messages for these events:
@itemize @bullet
@item
but @samp{x[(void)i,j]} will not.
@item
-An unsigned value is compared against zero with @samp{<} or @samp{<=}.
+An unsigned value is compared against zero with @samp{<} or @samp{>=}.
@item
A comparison like @samp{x<=y<=z} appears; this is equivalent to
incorrect result when the signed value is converted to unsigned.
(But don't warn if @option{-Wno-sign-compare} is also specified.)
-@item
-An aggregate has a partly bracketed initializer.
-For example, the following code would evoke such a warning,
-because braces are missing around the initializer for @code{x.h}:
-
-@smallexample
-struct s @{ int f, g; @};
-struct t @{ struct s h; int i; @};
-struct t x = @{ 1, 2, 3 @};
-@end smallexample
-
@item
An aggregate has an initializer which does not initialize all members.
For example, the following code would cause such a warning, because
struct s @{ int f, g, h; @};
struct s x = @{ 3, 4 @};
@end smallexample
+
+@item
+A function parameter is declared without a type specifier in K&R-style
+functions:
+
+@smallexample
+void foo(bar) @{ @}
+@end smallexample
+
+@item
+An empty body occurs in an @samp{if} or @samp{else} statement.
+
+@item
+A pointer is compared against integer zero with @samp{<}, @samp{<=},
+@samp{>}, or @samp{>=}.
+
+@item
+A variable might be changed by @samp{longjmp} or @samp{vfork}.
+
+@item
+Any of several floating-point events that often indicate errors, such as
+overflow, underflow, loss of precision, etc.
+
+@item @r{(C++ only)}
+An enumerator and a non-enumerator both appear in a conditional expression.
+
+@item @r{(C++ only)}
+A non-static reference or non-static @samp{const} member appears in a
+class without constructors.
+
+@item @r{(C++ only)}
+Ambiguous virtual bases.
+
+@item @r{(C++ only)}
+Subscripting an array which has been declared @samp{register}.
+
+@item @r{(C++ only)}
+Taking the address of a variable which has been declared @samp{register}.
+
+@item @r{(C++ only)}
+A base class is not initialized in a derived class' copy constrcutor.
@end itemize
@item -Wno-div-by-zero
@cindex signed and unsigned values, comparison warning
Warn when a comparison between signed and unsigned values could produce
an incorrect result when the signed value is converted to unsigned.
-This warning is also enabled by @option{-W}; to get the other warnings
-of @option{-W} without this warning, use @samp{-W -Wno-sign-compare}.
+This warning is also enabled by @option{-Wextra}; to get the other warnings
+of @option{-Wextra} without this warning, use @samp{-Wextra -Wno-sign-compare}.
@item -Waggregate-return
@opindex Waggregate-return
extern int warn_system_headers;
-/* Do print extra warnings (such as for uninitialized variables). -W. */
+/* Do print extra warnings (such as for uninitialized variables).
+ -W/-Wextra. */
extern int extra_warnings;
}
/* Warn about unused parms if extra warnings were specified. */
- /* Either ``-W -Wunused'' or ``-Wunused-parameter'' enables this
+ /* Either ``-Wextra -Wunused'' or ``-Wunused-parameter'' enables this
warning. WARN_UNUSED_PARAMETER is negative when set by
- -Wunused. */
+ -Wunused. Note that -Wall implies -Wunused, so ``-Wall -Wextra'' will
+ also give these warnings. */
if (warn_unused_parameter > 0
|| (warn_unused_parameter < 0 && extra_warnings))
{
if (want_value == -1)
want_value = expr_stmts_for_value != 0;
- /* If -W, warn about statements with no side effects,
+ /* If -Wextra, warn about statements with no side effects,
except for an explicit cast to void (e.g. for assert()), and
except for last statement in ({...}) where they may be useful. */
if (! want_value
int warn_system_headers = 0;
-/* Print various extra warnings. -W. */
+/* Print various extra warnings. -W/-Wextra. */
int extra_warnings = 0;
int warn_strict_aliasing;
-/* Likewise for -W. */
+/* Like f_options, but for -W. */
static const lang_independent_options W_options[] =
{
N_("Warn when an optimization pass is disabled") },
{"deprecated-declarations", &warn_deprecated_decl, 1,
N_("Warn about uses of __attribute__((deprecated)) declarations") },
+ {"extra", &extra_warnings, 1,
+ N_("Print extra (possibly unwanted) warnings") },
{"missing-noreturn", &warn_missing_noreturn, 1,
N_("Warn about functions which might be candidates for attribute noreturn") },
{"strict-aliasing", &warn_strict_aliasing, 1,
printf (_(" -pedantic Issue warnings needed by strict compliance to ISO C\n"));
printf (_(" -pedantic-errors Like -pedantic except that errors are produced\n"));
printf (_(" -w Suppress warnings\n"));
- printf (_(" -W Enable extra warnings\n"));
for (i = ARRAY_SIZE (W_options); i--;)
{
{
set_Wunused (0);
}
+ else if (!strcmp (arg, "extra"))
+ {
+ /* We save the value of warn_uninitialized, since if they put
+ -Wuninitialized on the command line, we need to generate a
+ warning about not using it without also specifying -O. */
+ if (warn_uninitialized != 1)
+ warn_uninitialized = 2;
+ }
else
return 0;
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