https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80793
--- Comment #6 from Eric Gallager <egallager at gcc dot gnu.org> --- (In reply to Manuel López-Ibáñez from comment #5) > (In reply to Martin Sebor from comment #0) > > There are several issues conflated here. > > > t.c: In function ‘f’: > > t.c:3:46: warning: signed and unsigned type in conditional expression > > [-Wsign-compare] > > unsigned char c = i ? (-__SCHAR_MAX__ - 1) : 1U; > > This warning should be moved to where -Wsign-conversion is handled to avoid > emitting both. > > The reason we cannot simply remove -Wsign-compare is because > -Wsign-conversion is not enabled by neither -Wall nor -Wextra, while > -Wsign-compare is. Only in C++ though, and this bug is for plain C > > The reason -Wsign-conversion is not enabled by neither -Wall nor -Wextra is > because it has annoying false positives like PR40752. Clang doesn't have > those. > > > t.c:3:46: warning: negative integer implicitly converted to unsigned type > > [-Wsign-conversion] > > This is same warning as Clang gives, just less informative than Clang's. > Printing the types should be easy. > > > t.c:3:21: warning: conversion to ‘unsigned char’ alters ‘unsigned int’ > > constant value [-Wconversion] > > unsigned char c = i ? (-__SCHAR_MAX__ - 1) : 1U; > > This warning is a bug in my opinion. Probably the patch in PR40752 silences > it.
