18 Apr 2024 7:26:27 am Richard Biener <richard.guent...@gmail.com>:
On Thu, Apr 18, 2024 at 6:12 AM Peter Damianov <peter0...@disroot.org>
wrote:
This commit adds a new option to the driver that truncates one file
after
linking.
Tested likeso:
$ gcc hello.c -c
$ du -h hello.o
4.0K hello.o
$ gcc hello.o -truncate hello
$ ./a.out
Hello world
$ du -h hello.o
$ 0 hello.o
I suppose it should have been
$ gcc hello.o -truncate hello.o
in the example.
Correct.
Sorry about that.
$ gcc hello.o -truncate
gcc: error: missing filename after '-truncate'
The motivation for adding this is PR110710. It is used by lto-wrapper
to
truncate files in a shell-independent manner.
This looks good to me.
Thanks,
Richard.
Signed-off-by: Peter Damianov <peter0...@disroot.org>
---
v2: moved truncation to driver::final_actions
v2: moved handling of OPT_truncate to be in alphabetic order
gcc/common.opt | 6 ++++++
gcc/gcc.cc | 13 +++++++++++++
2 files changed, 19 insertions(+)
diff --git a/gcc/common.opt b/gcc/common.opt
index ad348844775..40cab3cb36a 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -422,6 +422,12 @@ Display target specific command line options
(including assembler and linker opt
-time
Driver Alias(time)
+;; Truncate the file specified after linking.
+;; This option is used by lto-wrapper to reduce the peak disk-usage
when
+;; linking with many .LTRANS units.
+truncate
+Driver Separate Undocumented MissingArgError(missing filename after
%qs)
+
-verbose
Driver Alias(v)
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index 728332b8153..b4169bbd3be 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -2138,6 +2138,10 @@ static int have_E = 0;
/* Pointer to output file name passed in with -o. */
static const char *output_file = 0;
+/* Pointer to input file name passed in with -truncate.
+ This file should be truncated after linking. */
+static const char *totruncate_file = 0;
+
/* This is the list of suffixes and codes (%g/%u/%U/%j) and the
associated
temp file. If the HOST_BIT_BUCKET is used for %j, no entry is
made for
it here. */
@@ -4538,6 +4542,10 @@ driver_handle_option (struct gcc_options *opts,
do_save = false;
break;
+ case OPT_truncate:
+ totruncate_file = arg;
+ break;
+
case OPT____:
/* "-###"
This is similar to -v except that there is no execution
@@ -9286,6 +9294,11 @@ driver::final_actions () const
delete_failure_queue ();
delete_temp_files ();
+ if (totruncate_file != NULL && !seen_error ())
+ /* Truncate file specified by -truncate.
+ Used by lto-wrapper to reduce temporary disk-space usage. */
+ truncate(totruncate_file, 0);
+
if (print_help_list)
{
printf (("\nFor bug reporting instructions, please see:\n"));
--
2.39.2
