| Message ID | 20231113190401.759232-1-jwakely@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: Link extended FP conversion pedwarns to -Wnarrowing [PR111842] | expand |
On 11/13/23 14:01, Jonathan Wakely wrote: > Tested x86_64-linux. Does this make sense for trunk? OK, thanks. > These forbidden conversions are defined as narrowing conversions, and we > already use -Wnarrowing to control other "ill-formed, but only warn by > default" diagnostics required by the standard. > > -- >8 -- > > Several users have been confused by the status of these warnings, > which can be misunderstood as "this might not be what you want", > rather than diagnostics required by the C++ standard. Add the text "ISO > C++ does not allow" to make this clear. > > Also link them to -Wnarrowing so that they can be disabled or promoted > to errors independently of other pedwarns. > > gcc/cp/ChangeLog: > > PR c++/111842 > PR c++/112498 > * call.cc (convert_like_internal): Use OPT_Wnarrowing for > pedwarns about illformed conversions involving extended > floating-point types. Clarify that ISO C++ requires these > diagnostics. > * g++.dg/cpp23/ext-floating16.C: New test. > * g++.dg/cpp23/ext-floating17.C: New test. > --- > gcc/cp/call.cc | 10 +++-- > gcc/testsuite/g++.dg/cpp23/ext-floating16.C | 40 ++++++++++++++++++++ > gcc/testsuite/g++.dg/cpp23/ext-floating17.C | 42 +++++++++++++++++++++ > 3 files changed, 88 insertions(+), 4 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/cpp23/ext-floating16.C > create mode 100644 gcc/testsuite/g++.dg/cpp23/ext-floating17.C > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index 4516677bcab..4b0c6c42f01 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -8303,15 +8303,17 @@ convert_like_internal (conversion *convs, tree expr, tree fn, int argnum, > totype)) > { > case 2: > - if (pedwarn (loc, 0, "converting to %qH from %qI with greater " > - "conversion rank", totype, TREE_TYPE (expr))) > + if (pedwarn (loc, OPT_Wnarrowing, "ISO C++ does not allow " > + "converting to %qH from %qI with greater " > + "conversion rank", totype, TREE_TYPE (expr))) > complained = 1; > else if (!complained) > complained = -1; > break; > case 3: > - if (pedwarn (loc, 0, "converting to %qH from %qI with unordered " > - "conversion ranks", totype, TREE_TYPE (expr))) > + if (pedwarn (loc, OPT_Wnarrowing, "ISO C++ does not allow " > + "converting to %qH from %qI with unordered " > + "conversion rank", totype, TREE_TYPE (expr))) > complained = 1; > else if (!complained) > complained = -1; > diff --git a/gcc/testsuite/g++.dg/cpp23/ext-floating16.C b/gcc/testsuite/g++.dg/cpp23/ext-floating16.C > new file mode 100644 > index 00000000000..d6a562d5cb0 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp23/ext-floating16.C > @@ -0,0 +1,40 @@ > +// P1467R9 - Extended floating-point types and standard names. > +// { dg-do compile { target c++23 } } > +// { dg-options "-pedantic-errors -Wno-narrowing" } > +// { dg-add-options float16 } > +// { dg-add-options float32 } > +// { dg-add-options float64 } > +// { dg-add-options float128 } > + > +#include "ext-floating.h" > + > +#ifdef __STRICT_ANSI__ > +#undef __SIZEOF_FLOAT128__ > +#endif > + > +using namespace std; > + > +#ifdef __STDCPP_FLOAT16_T__ > +#ifdef __STDCPP_FLOAT32_T__ > +float16_t f16c = 1.0F32; // { dg-bogus "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float32' with greater conversion rank" "" { target { float16 && float32 } } } > +#endif > +#ifdef __STDCPP_FLOAT64_T__ > +float16_t f16e = 1.0F64; // { dg-bogus "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float64' with greater conversion rank" "" { target { float16 && float64 } } } > +#endif > +#ifdef __STDCPP_FLOAT128_T__ > +float16_t f16g = 1.0F128; // { dg-bogus "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float128' with greater conversion rank" "" { target { float16 && float128 } } } > +#endif > +#endif > +#ifdef __STDCPP_FLOAT32_T__ > +#ifdef __STDCPP_FLOAT64_T__ > +float32_t f32e = 1.0F64; // { dg-bogus "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float64' with greater conversion rank" "" { target { float32 && float64 } } } > +#endif > +#ifdef __STDCPP_FLOAT128_T__ > +float32_t f32g = 1.0F128; // { dg-bogus "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float128' with greater conversion rank" "" { target { float32 && float128 } } } > +#endif > +#endif > +#ifdef __STDCPP_FLOAT64_T__ > +#ifdef __STDCPP_FLOAT128_T__ > +float64_t f64g = 1.0F128; // { dg-bogus "converting to 'std::float64_t' \\\{aka '_Float64'\\\} from '_Float128' with greater conversion rank" "" { target { float64 && float128 } } } > +#endif > +#endif > diff --git a/gcc/testsuite/g++.dg/cpp23/ext-floating17.C b/gcc/testsuite/g++.dg/cpp23/ext-floating17.C > new file mode 100644 > index 00000000000..796e045537a > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp23/ext-floating17.C > @@ -0,0 +1,42 @@ > +// P1467R9 - Extended floating-point types and standard names. > +// { dg-do compile { target c++23 } } > +// { dg-options "-Werror=narrowing" } > +// { dg-add-options float16 } > +// { dg-add-options float32 } > +// { dg-add-options float64 } > +// { dg-add-options float128 } > +// { dg-prune-output "some warnings being treated as errors" } > + > +#include "ext-floating.h" > + > +#ifdef __STRICT_ANSI__ > +#undef __SIZEOF_FLOAT128__ > +#endif > + > +using namespace std; > + > +#ifdef __STDCPP_FLOAT16_T__ > +#ifdef __STDCPP_FLOAT32_T__ > +float16_t f16c = 1.0F32; // { dg-error "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float32' with greater conversion rank" "" { target { float16 && float32 } } } > +#endif > +#ifdef __STDCPP_FLOAT64_T__ > +float16_t f16e = 1.0F64; // { dg-error "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float64' with greater conversion rank" "" { target { float16 && float64 } } } > +#endif > +#ifdef __STDCPP_FLOAT128_T__ > +float16_t f16g = 1.0F128; // { dg-error "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float128' with greater conversion rank" "" { target { float16 && float128 } } } > +#endif > +#endif > +#ifdef __STDCPP_FLOAT32_T__ > +#ifdef __STDCPP_FLOAT64_T__ > +float32_t f32e = 1.0F64; // { dg-error "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float64' with greater conversion rank" "" { target { float32 && float64 } } } > +#endif > +#ifdef __STDCPP_FLOAT128_T__ > +float32_t f32g = 1.0F128; // { dg-error "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float128' with greater conversion rank" "" { target { float32 && float128 } } } > +#endif > +#endif > +#ifdef __STDCPP_FLOAT64_T__ > +#ifdef __STDCPP_FLOAT128_T__ > +float64_t f64g = 1.0F128; // { dg-error "converting to 'std::float64_t' \\\{aka '_Float64'\\\} from '_Float128' with greater conversion rank" "" { target { float64 && float128 } } } > +#endif > +#endif > +
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 4516677bcab..4b0c6c42f01 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -8303,15 +8303,17 @@ convert_like_internal (conversion *convs, tree expr, tree fn, int argnum, totype)) { case 2: - if (pedwarn (loc, 0, "converting to %qH from %qI with greater " - "conversion rank", totype, TREE_TYPE (expr))) + if (pedwarn (loc, OPT_Wnarrowing, "ISO C++ does not allow " + "converting to %qH from %qI with greater " + "conversion rank", totype, TREE_TYPE (expr))) complained = 1; else if (!complained) complained = -1; break; case 3: - if (pedwarn (loc, 0, "converting to %qH from %qI with unordered " - "conversion ranks", totype, TREE_TYPE (expr))) + if (pedwarn (loc, OPT_Wnarrowing, "ISO C++ does not allow " + "converting to %qH from %qI with unordered " + "conversion rank", totype, TREE_TYPE (expr))) complained = 1; else if (!complained) complained = -1; diff --git a/gcc/testsuite/g++.dg/cpp23/ext-floating16.C b/gcc/testsuite/g++.dg/cpp23/ext-floating16.C new file mode 100644 index 00000000000..d6a562d5cb0 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/ext-floating16.C @@ -0,0 +1,40 @@ +// P1467R9 - Extended floating-point types and standard names. +// { dg-do compile { target c++23 } } +// { dg-options "-pedantic-errors -Wno-narrowing" } +// { dg-add-options float16 } +// { dg-add-options float32 } +// { dg-add-options float64 } +// { dg-add-options float128 } + +#include "ext-floating.h" + +#ifdef __STRICT_ANSI__ +#undef __SIZEOF_FLOAT128__ +#endif + +using namespace std; + +#ifdef __STDCPP_FLOAT16_T__ +#ifdef __STDCPP_FLOAT32_T__ +float16_t f16c = 1.0F32; // { dg-bogus "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float32' with greater conversion rank" "" { target { float16 && float32 } } } +#endif +#ifdef __STDCPP_FLOAT64_T__ +float16_t f16e = 1.0F64; // { dg-bogus "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float64' with greater conversion rank" "" { target { float16 && float64 } } } +#endif +#ifdef __STDCPP_FLOAT128_T__ +float16_t f16g = 1.0F128; // { dg-bogus "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float128' with greater conversion rank" "" { target { float16 && float128 } } } +#endif +#endif +#ifdef __STDCPP_FLOAT32_T__ +#ifdef __STDCPP_FLOAT64_T__ +float32_t f32e = 1.0F64; // { dg-bogus "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float64' with greater conversion rank" "" { target { float32 && float64 } } } +#endif +#ifdef __STDCPP_FLOAT128_T__ +float32_t f32g = 1.0F128; // { dg-bogus "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float128' with greater conversion rank" "" { target { float32 && float128 } } } +#endif +#endif +#ifdef __STDCPP_FLOAT64_T__ +#ifdef __STDCPP_FLOAT128_T__ +float64_t f64g = 1.0F128; // { dg-bogus "converting to 'std::float64_t' \\\{aka '_Float64'\\\} from '_Float128' with greater conversion rank" "" { target { float64 && float128 } } } +#endif +#endif diff --git a/gcc/testsuite/g++.dg/cpp23/ext-floating17.C b/gcc/testsuite/g++.dg/cpp23/ext-floating17.C new file mode 100644 index 00000000000..796e045537a --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/ext-floating17.C @@ -0,0 +1,42 @@ +// P1467R9 - Extended floating-point types and standard names. +// { dg-do compile { target c++23 } } +// { dg-options "-Werror=narrowing" } +// { dg-add-options float16 } +// { dg-add-options float32 } +// { dg-add-options float64 } +// { dg-add-options float128 } +// { dg-prune-output "some warnings being treated as errors" } + +#include "ext-floating.h" + +#ifdef __STRICT_ANSI__ +#undef __SIZEOF_FLOAT128__ +#endif + +using namespace std; + +#ifdef __STDCPP_FLOAT16_T__ +#ifdef __STDCPP_FLOAT32_T__ +float16_t f16c = 1.0F32; // { dg-error "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float32' with greater conversion rank" "" { target { float16 && float32 } } } +#endif +#ifdef __STDCPP_FLOAT64_T__ +float16_t f16e = 1.0F64; // { dg-error "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float64' with greater conversion rank" "" { target { float16 && float64 } } } +#endif +#ifdef __STDCPP_FLOAT128_T__ +float16_t f16g = 1.0F128; // { dg-error "converting to 'std::float16_t' \\\{aka '_Float16'\\\} from '_Float128' with greater conversion rank" "" { target { float16 && float128 } } } +#endif +#endif +#ifdef __STDCPP_FLOAT32_T__ +#ifdef __STDCPP_FLOAT64_T__ +float32_t f32e = 1.0F64; // { dg-error "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float64' with greater conversion rank" "" { target { float32 && float64 } } } +#endif +#ifdef __STDCPP_FLOAT128_T__ +float32_t f32g = 1.0F128; // { dg-error "converting to 'std::float32_t' \\\{aka '_Float32'\\\} from '_Float128' with greater conversion rank" "" { target { float32 && float128 } } } +#endif +#endif +#ifdef __STDCPP_FLOAT64_T__ +#ifdef __STDCPP_FLOAT128_T__ +float64_t f64g = 1.0F128; // { dg-error "converting to 'std::float64_t' \\\{aka '_Float64'\\\} from '_Float128' with greater conversion rank" "" { target { float64 && float128 } } } +#endif +#endif +