On Mon, Jun 24, 2013 at 9:14 PM, Xinliang David Li <davi...@google.com> wrote: > To avoid printing twice, can you just do > > opt_type = (warn_conversion ? OPT_Wconversion : OPT_Wreal_conversion); > warning_at (loc, opt_type, ...);
Thanks for the suggestion. I have updated the enclosed patch and retested. Okay for google/gcc-4_8? Thanks, Sharad 2013-06-24 <l...@google.com> * doc/invoke.texi: Document new option -Wreal-conversion. * c-family/c.opt: Handle new option. * c-family/c-opts.c (c_common_post_options): Ditto. * c-family/c-common.c (conversion_warning): Ditto. testsuite/ChangeLog: * testsuite/gcc.dg/Wreal-conversion-1.c: New test. * testsuite/g++.dg/warn/Wreal-conversion-1.C: Ditto. Index: doc/invoke.texi =================================================================== --- doc/invoke.texi (revision 200359) +++ doc/invoke.texi (working copy) @@ -237,7 +237,7 @@ Objective-C and Objective-C++ Dialects}. -Wno-attributes -Wno-builtin-macro-redefined @gol -Wc++-compat -Wc++11-compat -Wcast-align -Wcast-qual @gol -Wchar-subscripts -Wclobbered -Wcomment @gol --Wconversion -Wcoverage-mismatch -Wno-cpp -Wno-deprecated @gol +-Wconversion -Wreal-conversion -Wcoverage-mismatch -Wno-cpp -Wno-deprecated @gol -Wno-deprecated-declarations -Wdisabled-optimization @gol -Wno-div-by-zero -Wdouble-promotion -Wempty-body -Wenum-compare @gol -Wno-endif-labels -Werror -Werror=* @gol @@ -4452,6 +4452,12 @@ reference to them. Warnings about conversions betw unsigned integers are disabled by default in C++ unless @option{-Wsign-conversion} is explicitly enabled. +@item -Wreal-conversion +@opindex Wreal-conversion +@opindex Wno-real-conversion +Warn for implicit type conversions from real (@code{double} or @code{float}) +to integral values. + @item -Wno-conversion-null @r{(C++ and Objective-C++ only)} @opindex Wconversion-null @opindex Wno-conversion-null Index: testsuite/gcc.dg/Wreal-conversion-1.c =================================================================== --- testsuite/gcc.dg/Wreal-conversion-1.c (revision 0) +++ testsuite/gcc.dg/Wreal-conversion-1.c (revision 0) @@ -0,0 +1,23 @@ +// { dg-do compile } +// { dg-options "-Wreal-conversion" } + +#include <stddef.h> + +int func1(int a) { + double f = a; + return f; // { dg-warning "conversion to" } +} + +double func3(); + +void func2() { + double g = 3.2; + float f; + int t = g; // { dg-warning "conversion to" } + int p; + p = f; // { dg-warning "conversion to" } + func1(g); // { dg-warning "conversion to" } + char c = f; // { dg-warning "conversion to" } + int q; + q = func3(); // { dg-warning "conversion to" } +} Index: testsuite/g++.dg/warn/Wreal-conversion-1.C =================================================================== --- testsuite/g++.dg/warn/Wreal-conversion-1.C (revision 0) +++ testsuite/g++.dg/warn/Wreal-conversion-1.C (revision 0) @@ -0,0 +1,24 @@ +// { dg-do compile } +// { dg-options "-Wreal-conversion" } + +#include <stddef.h> + +int func1(int a) { + double f = a; + return f; // { dg-warning "conversion to" } +} + +double func3(); + +void func2() { + double g = 3.2; + float f; + int t = g; // { dg-warning "conversion to" } + bool b = g; + int p; + p = f; // { dg-warning "conversion to" } + func1(g); // { dg-warning "conversion to" } + char c = f; // { dg-warning "conversion to" } + int q; + q = func3(); // { dg-warning "conversion to" } +} Index: c-family/c.opt =================================================================== --- c-family/c.opt (revision 200359) +++ c-family/c.opt (working copy) @@ -677,6 +677,10 @@ Wsign-compare C ObjC C++ ObjC++ EnabledBy(Wextra) ; +Wreal-conversion +C ObjC C++ ObjC++ Var(warn_real_conversion) Init(-1) Warning +Warn for implicit type conversions from real to integral values + Wsign-conversion C ObjC C++ ObjC++ Var(warn_sign_conversion) LangEnabledBy(C ObjC,Wconversion) Warn for implicit type conversions between signed and unsigned integers Index: c-family/c-opts.c =================================================================== --- c-family/c-opts.c (revision 200359) +++ c-family/c-opts.c (working copy) @@ -876,6 +876,12 @@ c_common_post_options (const char **pfilename) if (warn_packed_bitfield_compat == -1) warn_packed_bitfield_compat = 1; + /* Enable warning for converting real values to integral values + when -Wconversion is specified (unless disabled through + -Wno-real-conversion). */ + if (warn_real_conversion == -1) + warn_real_conversion = warn_conversion; + /* Special format checking options don't work without -Wformat; warn if they are used. */ if (!warn_format) Index: c-family/c-common.c =================================================================== --- c-family/c-common.c (revision 200359) +++ c-family/c-common.c (working copy) @@ -2668,7 +2668,7 @@ conversion_warning (tree type, tree expr) tree expr_type = TREE_TYPE (expr); location_t loc = EXPR_LOC_OR_HERE (expr); - if (!warn_conversion && !warn_sign_conversion) + if (!warn_conversion && !warn_sign_conversion && !warn_real_conversion) return; switch (TREE_CODE (expr)) @@ -2715,9 +2715,12 @@ conversion_warning (tree type, tree expr) default: /* 'expr' is not a constant. */ if (unsafe_conversion_p (type, expr, true)) - warning_at (loc, OPT_Wconversion, - "conversion to %qT from %qT may alter its value", - type, expr_type); + { + int warn_type = (warn_conversion ? OPT_Wconversion : OPT_Wreal_conversion); + warning_at (loc, warn_type, + "conversion to %qT from %qT may alter its value", + type, expr_type); + } } }