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authorGiuliano Belinassi <gbelinassi@suse.de>2021-11-16 13:25:32 -0300
committerGiuliano Belinassi <gbelinassi@suse.de>2021-11-19 11:27:21 -0300
commitc7381debe4c5dd7878338f38db98face1cfa6f90 (patch)
tree470e16f5fcf854a2d4591a9552e00acb41686233
parentcb09215ad0bbc96fd67aac16004d2131739df096 (diff)
Do not abort compilation when dump file is /dev/*
The `configure` scripts generated with autoconf often tests compiler features by setting output to `/dev/null`, which then sets the dump folder as being /dev/* and the compilation halts with an error because GCC cannot create files in /dev/. This is a problem when configure is testing for compiler features because it cannot tell if the failure was due to unsupported features or any other problem, and disable it even if it is working. As an example, running configure overriding CFLAGS="-fdump-ipa-clones" will result in several compiler-features as being disabled because of gcc halting with an error creating files in /dev/*. This commit fixes this issue by checking if the output file is /dev/null or /dev/zero. In this case we use the current working directory for dump output instead of the directory of the output file because we cannot write to /dev/*. gcc/ChangeLog 2021-11-16 Giuliano Belinassi <gbelinassi@suse.de> * gcc.c (process_command): Skip dumpdir override if file is a not_actual_file_p. * doc/invoke.texi: Update -dumpdir documentation. gcc/testsuite/ChangeLog 2021-11-16 Giuliano Belinassi <gbelinassi@suse.de> * gcc.dg/devnull-dump.c: New. Signed-off-by: Giuliano Belinassi <gbelinassi@suse.de>
-rw-r--r--gcc/doc/invoke.texi3
-rw-r--r--gcc/gcc.c3
-rw-r--r--gcc/testsuite/gcc.dg/devnull-dump.c7
3 files changed, 11 insertions, 2 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 1b02ea09197..49c8befd58a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1880,7 +1880,8 @@ named @file{dir/bar.*}, combining the given @var{dumppfx} with the
default @var{dumpbase} derived from the primary output name. Dump
outputs also take the input name suffix: @file{dir/bar.c.*}.
-It defaults to the location of the output file; options
+It defaults to the location of the output file, unless the output
+file is a special file like @code{/dev/null}. Options
@option{-save-temps=cwd} and @option{-save-temps=obj} override this
default, just like an explicit @option{-dumpdir} option. In case
multiple such options are given, the last one prevails:
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 506c2acc282..6ff22781042 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -5098,7 +5098,8 @@ process_command (unsigned int decoded_options_count,
bool explicit_dumpdir = dumpdir;
- if (!save_temps_overrides_dumpdir && explicit_dumpdir)
+ if ((!save_temps_overrides_dumpdir && explicit_dumpdir)
+ || (output_file && not_actual_file_p (output_file)))
{
/* Do nothing. */
}
diff --git a/gcc/testsuite/gcc.dg/devnull-dump.c b/gcc/testsuite/gcc.dg/devnull-dump.c
new file mode 100644
index 00000000000..378e0901c28
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/devnull-dump.c
@@ -0,0 +1,7 @@
+/* { dg-do assemble } */
+/* { dg-options "-fdump-ipa-clones -o /dev/null" } */
+
+int main()
+{
+ return 0;
+}