https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80777
Bug ID: 80777
Summary: long int structure members allocated incorrect 8 bytes
Product: gcc
Version: 5.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: jrose.manila at gmail dot com
Target Milestone: ---
Created attachment 41363
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41363&action=edit
source file describing bug
Problem: long int structure members are allocated incorrect 8 bytes (as if long
long), whereas retyping them with __uint32_t results in correct 4 bytes
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-cygwin/5.4.0/lto-wrapper.exe
Target: x86_64-pc-cygwin
Configured with:
/cygdrive/i/szsz/tmpp/gcc/gcc-5.4.0-1.x86_64/src/gcc-5.4.0/configure
--srcdir=/cygdrive/i/szsz/tmpp/gcc/gcc-5.4.0-1.x86_64/src/gcc-5.4.0
--prefix=/usr --exec-prefix=/usr --localstatedir=/var --sysconfdir=/etc
--docdir=/usr/share/doc/gcc --htmldir=/usr/share/doc/gcc/html -C
--build=x86_64-pc-cygwin --host=x86_64-pc-cygwin --target=x86_64-pc-cygwin
--without-libiconv-prefix --without-libintl-prefix --libexecdir=/usr/lib
--enable-shared --enable-shared-libgcc --enable-static
--enable-version-specific-runtime-libs --enable-bootstrap --enable-__cxa_atexit
--with-dwarf2 --with-tune=generic
--enable-languages=ada,c,c++,fortran,lto,objc,obj-c++ --enable-graphite
--enable-threads=posix --enable-libatomic --enable-libcilkrts --enable-libgomp
--enable-libitm --enable-libquadmath --enable-libquadmath-support
--enable-libssp --enable-libada --enable-libgcj-sublibs --disable-java-awt
--disable-symvers --with-ecj-jar=/usr/share/java/ecj.jar --with-gnu-ld
--with-gnu-as --with-cloog-include=/usr/include/cloog-isl
--without-libiconv-prefix --without-libintl-prefix --with-system-zlib
--enable-linker-build-id --with-default-libstdcxx-abi=gcc4-compatible
Thread model: posix
gcc version 5.4.0 (GCC)
running on cygwin64 for windows 10:
$ uname -a
CYGWIN_NT-10.0 Caroline-2 2.8.0(0.309/5/3) 2017-04-01 20:47 x86_64 Cygwin
Source: gcc5.4.0.bug.c (attached)
See definition of struct ProductId, members len, format, u.v3.edition.id
How to test:
1. Edit ProductId structure members len, format declarations to either
__uint32_t or unsigned long int
2. gcc -g -Wall -Wextra gcc5.4.0.bug.c -o gcc5.4.0.bug.exe
3. gdb ./gcc5.4.0.bug.exe
b main
b 142
run
c
n
print *pId
and you will see incorrect 8-byte values for pId->len and pId->format if you
declare as unsigned long int, or you will see correct 4-byte values if you
declare with __uint32_t
Further tests within gdb:
print sizeof(long int)
print sizeof(pId->len)
print sizeof(ii)
