On 01/02/2011 02:33, Joel Sherrill wrote:
> Hi,
>
> There are ~100 failures on each *-rtems* target
> in the latest test runs when various lto related
> flags are on. The symbols in questions are in the
> RTEMS libraries which are picked up via the
> -B... argument. Other symbols from the same
> library are resolved.
These have all cropped up since -fuse-linker-plugin became the default.
> Should LTO work with a target not using gold?
Yes, it should, but some work is needed at the binutils end. I am testing
the attached two patches at the moment; the idea is to have fully-debugged
support for LTO+plugin in the 2.20.1 release, to support 4.6.0 when it comes
out.
cheers,
DaveK
--
Apologies if dup - ENOPATCH first time I hit send.
>From 6cad541c1902edf5ceb483a20666a90be954e3d4 Mon Sep 17 00:00:00 2001
From: Dave Korn <[email protected]>
Date: Mon, 31 Jan 2011 03:26:05 +0000
Subject: [PATCH] ld/ChangeLog:
2011-01-29 Dave Korn <...
* ldlang.h (lang_input_statement_type): Add new 'claim_archive' flag.
* ldmain.c (add_archive_element): Set it if the member is claimed.
* ldlang.c (new_afile): Initialise claim_archive and claimed members.
(find_replacements_insert_point): New helper function.
(lang_process): After adding and opening replacement files passed
from plugin, splice them into correct place in statement list and
file chains to preserve critical link order.
(lang_list_insert_after): New helper function.
(lang_list_remove_tail): Likewise.
---
ld/ldlang.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++++++----
ld/ldlang.h | 3 +
ld/ldmain.c | 1 +
3 files changed, 129 insertions(+), 9 deletions(-)
diff --git a/ld/ldlang.c b/ld/ldlang.c
index 7ffe760..53d2901 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -85,6 +85,11 @@ static void print_statement_list (lang_statement_union_type *,
static void print_statements (void);
static void print_input_section (asection *, bfd_boolean);
static bfd_boolean lang_one_common (struct bfd_link_hash_entry *, void *);
+static void lang_list_insert_after (lang_statement_list_type *destlist,
+ lang_statement_list_type *srclist,
+ lang_statement_union_type **field);
+static void lang_list_remove_tail (lang_statement_list_type *destlist,
+ lang_statement_list_type *origlist);
static void lang_record_phdrs (void);
static void lang_do_version_exports_section (void);
static void lang_finalize_version_expr_head
@@ -1126,6 +1131,8 @@ new_afile (const char *name,
p->whole_archive = whole_archive;
p->loaded = FALSE;
p->missing_file = FALSE;
+ p->claimed = FALSE;
+ p->claim_archive = FALSE;
lang_statement_append (&input_file_chain,
(lang_statement_union_type *) p,
@@ -6394,6 +6401,38 @@ lang_relax_sections (bfd_boolean need_layout)
}
}
+/* Find the insert point for the plugin's replacement files. We
+ place them after the first claimed real object file, or if the
+ first claimed object is an archive member, after the last real
+ object file immediately preceding the archive. In the event
+ no objects have been claimed at all, we return the first dummy
+ object file on the list as the insert point; that works, but
+ the callee must be careful when relinking the file_chain as it
+ is not actually on that chain, only the statement_list and the
+ input_file list; in that case, the replacement files must be
+ inserted at the head of the file_chain. */
+
+static lang_input_statement_type *
+find_replacements_insert_point (void)
+{
+ lang_input_statement_type *claim1, *lastobject;
+ lastobject = &input_file_chain.head->input_statement;
+ for (claim1 = &file_chain.head->input_statement;
+ claim1 != NULL;
+ claim1 = &claim1->next->input_statement)
+ {
+ if (claim1->claimed)
+ return claim1->claim_archive ? lastobject : claim1;
+ /* Update lastobject if this is a real object file. */
+ if (claim1->the_bfd && (claim1->the_bfd->my_archive == NULL))
+ lastobject = claim1;
+ }
+ /* No files were claimed by the plugin. Choose the last object
+ file found on the list (maybe the first, dummy entry) as the
+ insert point. */
+ return lastobject;
+}
+
void
lang_process (void)
{
@@ -6420,21 +6459,54 @@ lang_process (void)
open_input_bfds (statement_list.head, FALSE);
#ifdef ENABLE_PLUGINS
+ if (plugin_active_plugins_p ())
{
- union lang_statement_union **listend;
+ lang_statement_list_type added;
+ lang_statement_list_type files, inputfiles;
/* Now all files are read, let the plugin(s) decide if there
are any more to be added to the link before we call the
- emulation's after_open hook. */
- listend = statement_list.tail;
- ASSERT (!*listend);
+ emulation's after_open hook. We create a private list of
+ input statements for this purpose, which we will eventually
+ insert into the global statment list after the first claimed
+ file. */
+ added = *stat_ptr;
+ /* We need to manipulate all three chains in synchrony. */
+ files = file_chain;
+ inputfiles = input_file_chain;
if (plugin_call_all_symbols_read ())
einfo (_("%P%F: %s: plugin reported error after all symbols read\n"),
plugin_error_plugin ());
- /* If any new files were added, they will be on the end of the
- statement list, and we can open them now by getting open_input_bfds
- to carry on from where it ended last time. */
- if (*listend)
- open_input_bfds (*listend, FALSE);
+ /* Open any newly added files, updating the file chains. */
+ open_input_bfds (added.head, FALSE);
+ /* Restore the global list pointer now they have all been added. */
+ lang_list_remove_tail (stat_ptr, &added);
+ /* And detach the fresh ends of the file lists. */
+ lang_list_remove_tail (&file_chain, &files);
+ lang_list_remove_tail (&input_file_chain, &inputfiles);
+ /* Were any new files added? */
+ if (added.head != NULL)
+ {
+ /* If so, we will insert them into the statement list immediately
+ after the first input file that was claimed by the plugin. */
+ lang_input_statement_type *claim1 = find_replacements_insert_point ();
+ /* If a plugin adds input files without having claimed any, we
+ don't really have a good idea where to place them. Just putting
+ them at the start or end of the list is liable to leave them
+ outside the crtbegin...crtend range. */
+ ASSERT (claim1 != NULL);
+ /* Splice the new statement list into the old one after claim1. */
+ lang_list_insert_after (stat_ptr, &added, &claim1->header.next);
+ /* Likewise for the file chains. */
+ lang_list_insert_after (&input_file_chain, &inputfiles,
+ &claim1->next_real_file);
+ /* We must be careful when relinking file_chain; we may need to
+ insert the new files at the head of the list if the insert
+ point chosen is the dummy first input file. */
+ if (claim1->filename)
+ lang_list_insert_after (&file_chain, &files, &claim1->next);
+ else
+ lang_list_insert_after (&file_chain, &files, &file_chain.head);
+ }
}
#endif /* ENABLE_PLUGINS */
@@ -6857,6 +6929,50 @@ lang_statement_append (lang_statement_list_type *list,
list->tail = field;
}
+/* Insert SRCLIST into DESTLIST after given element by chaining
+ on FIELD as the next-pointer. (Counterintuitively does not need
+ a pointer to the actual after-node itself, just its chain field.) */
+
+static void
+lang_list_insert_after (lang_statement_list_type *destlist,
+ lang_statement_list_type *srclist,
+ lang_statement_union_type **field)
+{
+ /* Are we adding at the very end of the list? */
+ if (*field == NULL)
+ {
+ /* (*field == NULL) should imply (destlist->tail == field),
+ if not then the element isn't really in the DESTLIST. */
+ ASSERT (destlist->tail == field);
+ /* Yes, append to and update tail pointer. */
+ *(destlist->tail) = srclist->head;
+ destlist->tail = srclist->tail;
+ }
+ else
+ {
+ /* We're inserting in the middle somewhere. */
+ *(srclist->tail) = *field;
+ *field = srclist->head;
+ }
+}
+
+/* Detach new nodes added to DESTLIST since the time ORIGLIST
+ was taken as a copy of it and leave them in ORIGLIST. */
+
+static void
+lang_list_remove_tail (lang_statement_list_type *destlist,
+ lang_statement_list_type *origlist)
+{
+ union lang_statement_union **savetail;
+ /* Check that ORIGLIST really is an earlier state of DESTLIST. */
+ ASSERT (origlist->head == destlist->head);
+ savetail = origlist->tail;
+ origlist->head = *(savetail);
+ origlist->tail = destlist->tail;
+ destlist->tail = savetail;
+ *savetail = NULL;
+}
+
/* Set the output format type. -oformat overrides scripts. */
void
diff --git a/ld/ldlang.h b/ld/ldlang.h
index 8aff0b3..105253a 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -290,6 +290,9 @@ typedef struct lang_input_statement_struct
/* Set if the file was claimed by a plugin. */
unsigned int claimed : 1;
+ /* Set if the file was claimed from an archive. */
+ unsigned int claim_archive : 1;
+
} lang_input_statement_type;
typedef struct
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 19c42d9..1c6d4be 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -834,6 +834,7 @@ add_archive_element (struct bfd_link_info *info,
/* Substitute the dummy BFD. */
input->the_bfd = file.handle;
input->claimed = TRUE;
+ input->claim_archive = TRUE;
bfd_make_readable (input->the_bfd);
*subsbfd = input->the_bfd;
}
>From fd18b9d502186db79ec84bfd5f43b0eb285281c6 Mon Sep 17 00:00:00 2001
From: Dave Korn <[email protected]>
Date: Tue, 1 Feb 2011 10:18:04 +0000
Subject: [PATCH] ld/ChangeLog:
2011-01-29 Dave Korn <...
* ldlang.c (rescan_input_libs): New function.
(lang_process): Call it if replacement files have added any new
undefined symbols.
* plugin.c (plugin_opt_plugin_arg): Discard any instances of the
(now-obsolete) "-pass-through=" option if found.
---
ld/ldlang.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ld/plugin.c | 3 +++
2 files changed, 62 insertions(+), 0 deletions(-)
diff --git a/ld/ldlang.c b/ld/ldlang.c
index 53d2901..4e528d1 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -3273,6 +3273,60 @@ open_input_bfds (lang_statement_union_type *s, bfd_boolean force)
einfo ("%F");
}
+/* Rescan all the input library files starting from S. */
+
+static void
+rescan_input_libs (lang_statement_union_type *s)
+{
+ for (; s != NULL; s = s->header.next)
+ {
+ switch (s->header.type)
+ {
+ default:
+ break;
+ case lang_group_statement_enum:
+ {
+ struct bfd_link_hash_entry *undefs;
+ /* We must continually search the entries in the group
+ until no new symbols are added to the list of undefined
+ symbols. */
+ do
+ {
+ undefs = link_info.hash->undefs_tail;
+ rescan_input_libs (s->group_statement.children.head);
+ }
+ while (undefs != link_info.hash->undefs_tail);
+ }
+ break;
+ case lang_input_statement_enum:
+ if (s->input_statement.real && s->input_statement.the_bfd
+ && bfd_check_format (s->input_statement.the_bfd, bfd_archive))
+ {
+ lang_statement_list_type add;
+
+ /* If this archive has already been searched, then
+ force it to be researched unless the whole archive
+ has been loaded already. */
+ if (!s->input_statement.whole_archive
+ && s->input_statement.loaded)
+ s->input_statement.loaded = FALSE;
+
+ lang_list_init (&add);
+
+ if (!load_symbols (&s->input_statement, &add))
+ config.make_executable = FALSE;
+
+ if (add.head != NULL)
+ {
+ *add.tail = s->header.next;
+ s->header.next = add.head;
+ }
+ }
+ break;
+ }
+ }
+}
+
/* Add a symbol to a hash of symbols used in DEFINED (NAME) expressions. */
void
@@ -6463,6 +6517,7 @@ lang_process (void)
{
lang_statement_list_type added;
lang_statement_list_type files, inputfiles;
+ struct bfd_link_hash_entry *undefs = link_info.hash->undefs_tail;
/* Now all files are read, let the plugin(s) decide if there
are any more to be added to the link before we call the
emulation's after_open hook. We create a private list of
@@ -6506,6 +6561,10 @@ lang_process (void)
lang_list_insert_after (&file_chain, &files, &claim1->next);
else
lang_list_insert_after (&file_chain, &files, &file_chain.head);
+ /* Now, if there are any new undefined symbols, rescan any
+ libraries after the insertion point. */
+ if (undefs != link_info.hash->undefs_tail)
+ rescan_input_libs (claim1->next_real_file);
}
}
#endif /* ENABLE_PLUGINS */
diff --git a/ld/plugin.c b/ld/plugin.c
index b285787..cd8aeb9 100644
--- a/ld/plugin.c
+++ b/ld/plugin.c
@@ -214,6 +214,9 @@ plugin_opt_plugin_arg (const char *arg)
if (!last_plugin)
return set_plugin_error (_("<no plugin>"));
+ if (CONST_STRNEQ (arg, "-pass-through="))
+ return 0;
+
newarg = xmalloc (sizeof *newarg);
newarg->arg = arg;
newarg->next = NULL;
