This adds a -ltrans-objects option to lto-plugin that by-passes
lto-wrapper invocation and instead feeds LD the final LTRANS objects
directly from the response file given as argument to the option.
This allows LD issues involving the linker-plugin path to be
debugged in an easier way with just the IR objects (their symtab)
and the LTRANS objects as testcase.
I've tested the path re-building stage2 build/genmatch from an
LTO bootstrap and got a bit-identical executable by adding
-plugin-opt=-ltrans-objects=y to the original collect2 invocation,
seeding y with the final objects as printed by building genmatch
with -save-temps -v.
Bootstrapped and tested on x86_64-unknown-linux-gnu.
OK?
2021-06-22 Richard Biener <rguent...@suse.de>
lto-plugin/
* lto-plugin.c (ltrans_objects): New global.
(all_symbols_read_handler): If -ltrans-objects was specified,
add the output files from the specified file directly.
(process_option): Handle -ltrans-objects.
---
lto-plugin/lto-plugin.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
index ff79f4ac462..6ab9822f369 100644
--- a/lto-plugin/lto-plugin.c
+++ b/lto-plugin/lto-plugin.c
@@ -190,6 +190,8 @@ static int lto_wrapper_num_args;
static char **pass_through_items = NULL;
static unsigned int num_pass_through_items;
+static char *ltrans_objects = NULL;
+
static bool debug;
static bool save_temps;
static bool verbose;
@@ -739,6 +741,14 @@ all_symbols_read_handler (void)
return LDPS_OK;
}
+ if (ltrans_objects)
+ {
+ FILE *objs = fopen (ltrans_objects, "r");
+ add_output_files (objs);
+ fclose (objs);
+ return LDPS_OK;
+ }
+
lto_argv = (char **) xcalloc (sizeof (char *), num_lto_args);
lto_arg_ptr = (const char **) lto_argv;
assert (lto_wrapper_argv);
@@ -1345,6 +1355,8 @@ process_option (const char *option)
break;
}
}
+ else if (startswith (option, "-ltrans-objects="))
+ ltrans_objects = xstrdup (option + strlen ("-ltrans-objects="));
else
{
int size;
--
2.26.2
