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| author | Manuel López-Ibáñez <manu@gcc.gnu.org> | 2007-05-20 20:29:55 +0000 |
|---|---|---|
| committer | Manuel López-Ibáñez <manu@gcc.gnu.org> | 2007-05-20 20:29:55 +0000 |
| commit | f6aa72dd497916b60e7a3c29e235241dadba3274 (patch) | |
| tree | 90312ab1a9121fa6e7864a7b15bdaf3260ab1b8b /gcc/doc | |
| parent | da5a2efd39b67a36c4e70f059ffbbb6103606f3e (diff) | |
| download | gcc-f6aa72dd497916b60e7a3c29e235241dadba3274.zip gcc-f6aa72dd497916b60e7a3c29e235241dadba3274.tar.gz gcc-f6aa72dd497916b60e7a3c29e235241dadba3274.tar.bz2 | |
re PR middle-end/7651 (Define -Wextra strictly in terms of other warning flags)
2007-05-20 Manuel Lopez-Ibanez <manu@gcc.gnu.org>
PR middle-end/7651
PR c++/11856
PR c/12963
PR c/23587
PR other/29694
* c.opt (Wtype-limits): New.
* doc/invoke.texi (Wtype-limits): Document it.
(Wextra): Enabled by -Wextra.
* c-opts.c (c_common_post_options): Enabled by -Wextra.
* c-common.c (shorten_compare): Warn with Wtype-limits.
testsuite/
* gcc.dg/compare6.c: Replace Wall with Wtype-limits.
* gcc.dg/Wtype-limits.c: New.
* gcc.dg/Wtype-limits-Wextra.c: New.
* gcc.dg/Wtype-limits-no.c: New.
* g++.dg/warn/Wtype-limits.C: New.
* g++.dg/warn/Wtype-limits-Wextra.C: New.
* g++.dg/warn/Wtype-limits-no.C: New.
From-SVN: r124875
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/invoke.texi | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 7be8167..d8260ba 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -224,7 +224,7 @@ Objective-C and Objective-C++ Dialects}. @item Warning Options @xref{Warning Options,,Options to Request or Suppress Warnings}. @gccoptlist{-fsyntax-only -pedantic -pedantic-errors @gol --w -Wextra -Wall -Waddress -Waggregate-return -Warray-bounds @gol +-w -Wextra -Wall -Waddress -Waggregate-return -Warray-bounds @gol -Wno-attributes -Wc++-compat -Wc++0x-compat -Wcast-align -Wcast-qual @gol -Wchar-subscripts -Wclobbered -Wcomment @gol -Wconversion -Wcoverage-mismatch -Wno-deprecated-declarations @gol @@ -251,7 +251,7 @@ Objective-C and Objective-C++ Dialects}. -Wstrict-aliasing -Wstrict-aliasing=n @gol -Wstrict-overflow -Wstrict-overflow=@var{n} @gol -Wswitch -Wswitch-default -Wswitch-enum @gol --Wsystem-headers -Wtrigraphs -Wundef -Wuninitialized @gol +-Wsystem-headers -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized @gol -Wunknown-pragmas -Wno-pragmas -Wunreachable-code @gol -Wunused -Wunused-function -Wunused-label -Wunused-parameter @gol -Wunused-value -Wunused-variable @gol @@ -3134,7 +3134,11 @@ messages for these events: @itemize @bullet @item -An unsigned value is compared against zero with @samp{<} or @samp{>=}. +Warn if a comparison is always true or always false due to the limited +range of the data type, but do not warn for constant expressions. For +example, warn if an unsigned variable is compared against zero with +@samp{<} or @samp{>=}. This warning can be independently controlled +by @option{-Wtype-limits}. @item @r{(C only)} Storage-class specifiers like @code{static} are not the first things @@ -3376,6 +3380,15 @@ convenience in calculations with @code{void *} pointers and pointers to functions. In C++, warn also when an arithmetic operation involves @code{NULL}. This warning is also enabled by @option{-pedantic}. +@item -Wtype-limits +@opindex Wtype-limits +@opindex Wno-type-limits +Warn if a comparison is always true or always false due to the limited +range of the data type, but do not warn for constant expressions. For +example, warn if an unsigned variable is compared against zero with +@samp{<} or @samp{>=}. This warning is also enabled by +@option{-Wextra}. + @item -Wbad-function-cast @r{(C only)} @opindex Wbad-function-cast Warn whenever a function call is cast to a non-matching type. |