http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49626
Summary: Explicit conversion skipped when followed by
conversion to a wider type
Product: gcc
Version: 4.3.2
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: fn42...@fmi.uni-sofia.bg
Hello.
I think I've encountered a case regarding conversions between integral types.
It is demonstrated by the attached file which, when compiled with
"-Wsign-conversion", makes g++ produce the following warning:
sign-conversion-bug.cpp: In function 'long unsigned int f()':
sign-conversion-bug.cpp:5: warning: conversion to 'long unsigned int' from
'short int' may change the sign of the result
The source code requests two conversions:
1. an explicit one from 'short int' to 'unsigned int';
2. an implicit one from 'unsigned int' to 'unsigned long int'.
However, g++ only seems to attempt a single conversion -- an implicit one from
'short int' to 'unsigned long int'. Is this the intended behaviour?
Output from "g++ -v":
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.2-1.1'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-targets=all --enable-cld
--enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu
--target=i486-linux-gnu
Thread model: posix
gcc version 4.3.2 (Debian 4.3.2-1.1)
I also tested with gcc versions 4.3.6 and 4.4.6, and I got the same results.
Regards,
Angel Tsankov
