https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110844
Bug ID: 110844
Summary: LTO sometimes fail with -save-temp -dumpdir options
Product: gcc
Version: 13.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: frankhb1989 at gmail dot com
CC: marxin at gcc dot gnu.org
Target Milestone: ---
Cases:
$ cd /tmp
$ g++ --version
g++ (GCC) 13.1.1 20230714
Copyright (C) 2023 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ echo 'int main(){}' > a.cc
$ g++ -flto -c a.cc -o a.o
$ g++ -flto -save-temps -dumpdir . a.o
$ g++ -flto -c a.cc -o a.o -save-temps -dumpdir .
$ g++ -flto -save-temps -dumpdir . a.o
$ g++ -flto -save-temps -dumpdir /tmp/ a.o
/usr/sbin/ld: error: could not open arguments file
collect2: error: ld returned 1 exit status
The error message is from lto-plugin.c. Setting the environment variables
(indicated by 'g++ -v' and then 'collect2 -v' from the result) properly, by "b
fopen if *(char*)$rsi == 'w'" for ld running in gdb a few times, it shows
something goes wrong in 'link_output_name' which forms 'arguments_file_name':
the variable incorrectly contains all the remain characters in the command
line. (This is also reproduced in MSYS2 ld which has no debug symbols
distributed together, after changing $rsi to $rdx.) The parsing implementation
of '-dumpdir' arguments introduced in 1dedc12d186a110854537e1279b4e6c29f2df35a
then looks quite suspicious.
