https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120315
Bug ID: 120315
Summary: std::format gcc 14 / 15 interop issue
Product: gcc
Version: 15.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: nilsgladitz at gmail dot com
Target Milestone: ---
Created attachment 61443
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61443&action=edit
Testcase
I got undefined behavior (segfault, missing output or exceptions) when using a
gcc 14 compiled library with a gcc 15 compiled executable.
The issue does not seem to be reproducible when the same compiler is used for
both the library and the compiler.
Attached is a reduced test case that I compile on x86_64 GNU Linux thusly:
/opt/gcc-14.2.0/bin/g++ -fvisibility=hidden -fvisibility-inlines-hidden -shared
-fPIC -std=c++23 library.cpp -o liblibrary14.so -Wl,-soname,liblibrary14.so
/opt/gcc-15.1.0/bin/g++ -fvisibility=hidden -fvisibility-inlines-hidden -shared
-fPIC -std=c++23 library.cpp -o liblibrary15.so -Wl,-soname,liblibrary15.so
/opt/gcc-15.1.0/bin/g++ -std=c++23 executable.cpp -o executable14
liblibrary14.so '-Wl,-rpath,$ORIGIN'
/opt/gcc-15.1.0/bin/g++ -std=c++23 executable.cpp -o executable15
liblibrary15.so '-Wl,-rpath,$ORIGIN'
Running executable15 I get the expected output:
Hello World
Running executable14 I get e.g.:
terminate called after throwing an instance of 'std::format_error'
what(): format error: invalid arg-id in format string
Aborted (core dumped)
I am unsure if maybe std::format isn't supposed to be ABI stable yet or if
there is something else not being done properly / well defined in the test
case.
