https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109554
Bug ID: 109554
Summary: Compiler generates incorrect code when the function
declared with returned parameterm but no 'return' in
its body
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: xvladsoft at yahoo dot com
Target Milestone: ---
Created attachment 54883
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54883&action=edit
The source file which shows issue.
Good day!
First of all, thanks alot for you efforts to create so nice compiler! It is
really nice: generates small and fast code!
But looks like I found an issue: the compiler does not generate a 'return
point' where the function is declared with not-void return parameter, but no
'return' operators in its body.
Details:
*** 1) Operation system:
uname -a
Linux XVlad-Work 4.19.0-22-amd64 #1 SMP Debian 4.19.260-1 (2022-09-29) x86_64
GNU/Linux
*** 2) Compiler version (according to https://gcc.godbolt.org/ issue
reproduces from 8.3.0 till the latest (12.+)):
gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 8.3.0-6'
--with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-8
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --with-target-system-zlib --enable-objc-gc=auto
--enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 8.3.0 (Debian 8.3.0-6)
*** 3) Command line to compile:
gcc -O3 ./SandBox_2.cpp
*** 4) Command line to execute:
./a.out 0
Observations:
Please, look at the code in the attached file:
- when it is compiled as:
/GccBug$ gcc -O0 ./SandBox_2.cpp
- program executes correctly:
/GccBug$ ./a.out 0
Hello world from SandBox-2!
8.3.0
Point-A 0, 0
- *BUT* when it is compiled as:
/GccBug$ gcc -O3 ./SandBox_2.cpp
- program crashes:
/GccBug$ ./a.out 0
Hello world from SandBox-2!
8.3.0
Point-A 0, 0
Point-B 1, 0
Segmentation fault <<<!!!!!!!
Best regards,
Vladimir.
