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Re: [PATCH] fix PR51910, take 2
On 02/02/2012 11:27 PM, Jakub Jelinek wrote:
Anyway, here is the tweaking all the symbols that demangle the same
equally patch (untested so far) as an alternative. On the example it
unfortunately causes also the D2 dtor into the link which wasn't there
otherwise (and with -Wl,--no-demangle). While D2 dtors are generally small,
perhaps it will sometimes force into the link also ctor or dtor variants
that couldn't be aliased together.
Hmm, I wrote up something quite similar on the plane. One difference is
that mine synchronizes .rpo files that start with some variants chosen
and others not. Does this make sense to you?
I wonder if it wouldn't be better to just use a linker plugin for -frepo
if the linker supports plugins.
Probably. But I don't feel motivated to write it.
Jason
commit 1f4b0d273cfd81948762d3922cdafac40a06a2cf
Author: Jason Merrill <jason@redhat.com>
Date: Thu Feb 2 00:07:44 2012 -0500
PR c++/51910
* tlink.c (demangled_hash_entry): Change mangled to a VEC.
(demangle_new_symbols): Fill it.
(scan_linker_output): Walk it.
(start_tweaking): Split out from scan_linker_output.
(maybe_tweak): Update sym->chosen.
* Makefile.in (COLLECT2_OBJS): Add vec.o and gcc-none.o
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index c9ecc4b..486538d 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1946,7 +1946,7 @@ gcc-ranlib.c: gcc-ar.c
gcc-nm.c: gcc-ar.c
cp $^ $@
-COLLECT2_OBJS = collect2.o collect2-aix.o tlink.o
+COLLECT2_OBJS = collect2.o collect2-aix.o tlink.o vec.o ggc-none.o
COLLECT2_LIBS = @COLLECT2_LIBS@
collect2$(exeext): $(COLLECT2_OBJS) $(LIBDEPS)
# Don't try modifying collect2 (aka ld) in place--it might be linking this.
diff --git a/gcc/testsuite/g++.dg/template/repo10.C b/gcc/testsuite/g++.dg/template/repo10.C
new file mode 100644
index 0000000..c92f7a5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/repo10.C
@@ -0,0 +1,16 @@
+// PR c++/51910
+// { dg-options -frepo }
+// { dg-require-host-local "" }
+// { dg-skip-if "dkms are not final links" { vxworks_kernel } }
+// { dg-final cleanup-repo-files }
+
+template<typename T>
+struct Foo
+{
+ virtual ~Foo() { }
+};
+
+int main( int, char*[] )
+{
+ Foo<int> test;
+}
diff --git a/gcc/tlink.c b/gcc/tlink.c
index f054047..67c7086 100644
--- a/gcc/tlink.c
+++ b/gcc/tlink.c
@@ -32,6 +32,7 @@ along with GCC; see the file COPYING3. If not see
#include "collect2.h"
#include "filenames.h"
#include "diagnostic-core.h"
+#include "vec.h"
/* TARGET_64BIT may be defined to use driver specific functionality. */
#undef TARGET_64BIT
@@ -67,10 +68,14 @@ typedef struct file_hash_entry
int tweaking;
} file;
+typedef const char *str;
+DEF_VEC_P(str);
+DEF_VEC_ALLOC_P(str,heap);
+
typedef struct demangled_hash_entry
{
const char *key;
- const char *mangled;
+ VEC(str,heap) *mangled;
} demangled;
/* Hash and comparison functions for these hash tables. */
@@ -435,9 +440,15 @@ maybe_tweak (char *line, file *f)
sym->tweaked = 1;
if (line[0] == 'O')
- line[0] = 'C';
+ {
+ line[0] = 'C';
+ sym->chosen = 1;
+ }
else
- line[0] = 'O';
+ {
+ line[0] = 'O';
+ sym->chosen = 0;
+ }
}
}
@@ -598,10 +609,34 @@ demangle_new_symbols (void)
continue;
dem = demangled_hash_lookup (p, true);
- dem->mangled = sym->key;
+ VEC_safe_push (str, heap, dem->mangled, sym->key);
}
}
+/* We want to tweak symbol SYM. Return true if all is well, false on
+ error. */
+
+static bool
+start_tweaking (symbol *sym)
+{
+ if (sym && sym->tweaked)
+ {
+ error ("'%s' was assigned to '%s', but was not defined "
+ "during recompilation, or vice versa",
+ sym->key, sym->file->key);
+ return 0;
+ }
+ if (sym && !sym->tweaking)
+ {
+ if (tlink_verbose >= 2)
+ fprintf (stderr, _("collect: tweaking %s in %s\n"),
+ sym->key, sym->file->key);
+ sym->tweaking = 1;
+ file_push (sym->file);
+ }
+ return true;
+}
+
/* Step through the output of the linker, in the file named FNAME, and
adjust the settings for each symbol encountered. */
@@ -616,8 +651,11 @@ scan_linker_output (const char *fname)
{
char *p = line, *q;
symbol *sym;
+ demangled *dem = 0;
int end;
int ok = 0;
+ unsigned ix;
+ str s;
/* On darwin9, we might have to skip " in " lines as well. */
if (skip_next_in_line
@@ -662,7 +700,6 @@ scan_linker_output (const char *fname)
/* Try a mangled name in quotes. */
{
char *oldq = q + 1;
- demangled *dem = 0;
q = 0;
/* On darwin9, we look for "foo" referenced from:\n\(.* in .*\n\)* */
@@ -718,9 +755,7 @@ scan_linker_output (const char *fname)
{
*q = 0;
dem = demangled_hash_lookup (p, false);
- if (dem)
- sym = symbol_hash_lookup (dem->mangled, false);
- else
+ if (!dem)
{
if (!strncmp (p, USER_LABEL_PREFIX,
strlen (USER_LABEL_PREFIX)))
@@ -730,24 +765,43 @@ scan_linker_output (const char *fname)
}
}
- if (sym && sym->tweaked)
+ if (dem)
+ {
+ /* We found a demangled name. If this is the name of a
+ constructor or destructor, there can be several mangled names
+ that match it, so choose or unchoose all of them. If some are
+ chosen and some not, leave the later ones that don't match
+ alone for now; either this will cause the link to suceed, or
+ on the next attempt we will switch all of them the other way
+ and that will cause it to succeed. */
+ int chosen = 0;
+ int len = VEC_length (str, dem->mangled);
+ ok = true;
+ FOR_EACH_VEC_ELT (str, dem->mangled, ix, s)
+ {
+ sym = symbol_hash_lookup (s, false);
+ if (ix == 0)
+ chosen = sym->chosen;
+ else if (sym->chosen != chosen)
+ /* Mismatch. */
+ continue;
+ /* Avoid an error about re-tweaking when we guess wrong in
+ the case of mismatch. */
+ if (len > 1)
+ sym->tweaked = false;
+ ok = start_tweaking (sym);
+ }
+ }
+ else
+ ok = start_tweaking (sym);
+
+ obstack_free (&temporary_obstack, temporary_firstobj);
+
+ if (!ok)
{
- error ("'%s' was assigned to '%s', but was not defined "
- "during recompilation, or vice versa",
- sym->key, sym->file->key);
fclose (stream);
return 0;
}
- if (sym && !sym->tweaking)
- {
- if (tlink_verbose >= 2)
- fprintf (stderr, _("collect: tweaking %s in %s\n"),
- sym->key, sym->file->key);
- sym->tweaking = 1;
- file_push (sym->file);
- }
-
- obstack_free (&temporary_obstack, temporary_firstobj);
}
fclose (stream);