To avoid printing twice, can you just do opt_type = (warn_conversion ? OPT_Wconversion : OPT_Wreal_conversion); warning_at (loc, opt_type, ...);
David On Mon, Jun 24, 2013 at 6:08 PM, Sharad Singhai <sing...@google.com> wrote: > Hi, > > This patch forward ports the -Wreal-conversion warning to > google/gcc-4_8 branch (google ref 39133-p2). I tweaked the patch a > little bit to avoid printing duplicate warnings when both -Wconversion > and -Wreal-conversion are specified. Also, I trimmed the test case to > avoid testing for integer-to-integer narrowing conversions as this > warning is about real conversions. > > Bootstrapped and tested on x86_64. 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: 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: doc/invoke.texi > =================================================================== > --- doc/invoke.texi (revision 200359) > +++ doc/invoke.texi (working copy) > @@ -193,7 +193,7 @@ in the following sections. > -fno-default-inline -fvisibility-inlines-hidden @gol > -fvisibility-ms-compat @gol > -fext-numeric-literals @gol > --Wabi -Wconversion-null -Wctor-dtor-privacy @gol > +-Wabi -Wconversion-null -Wctor-dtor-privacy @gol > -Wdelete-non-virtual-dtor -Wliteral-suffix -Wnarrowing @gol > -Wnoexcept -Wnon-virtual-dtor -Wreorder @gol > -Weffc++ -Wstrict-null-sentinel @gol > @@ -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: 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 +2715,17 @@ 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); > + { > + /* Do not print the same warning twice. */ > + bool printed = > + warning_at (loc, OPT_Wreal_conversion, > + "conversion to %qT from %qT may alter its value", > + type, expr_type); > + if (!printed) > + warning_at (loc, OPT_Wconversion, > + "conversion to %qT from %qT may alter its value", > + type, expr_type); > + } > } > }