On 06/26/2014 06:25 AM, Chen Gang wrote:
>
> BTW: one linux kernel member found a gcc issue for the latest version
> (4.10.0 20140622 or later), but for old version (e.g. 4.10.0 2014060*),
> it is OK. It is my chance to fix it (hope can finish within 2014-06-30).
>
For this issue, at present, I find root cause: when find duplicate decls,
it need merge with the old one, and let old and new share 'function_decl.f',
After free new, also free the old.
I shall continue analysing this issue, and welcome any members' suggestions
or completions.
The related git number is 71e19e54060804493e13748613077b0e69c0cfd9, and the
related contents are below:
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 54d0de7..47cf3cc 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,8 @@
+2014-06-07 Jan Hubicka <hubi...@ucw.cz>
+
+ * c-decl.c (merge_decls): Use set_decl_section_name.
+ (duplicate_decls): Remove node if it exists.
+
2014-06-05 S. Gilles <sgil...@terpmail.umd.edu>
PR c/53119
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 8fb3296..524b064 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -2304,8 +2304,10 @@ merge_decls (tree newdecl, tree olddecl, tree newtype,
tree oldtype)
We want to issue an error if the sections conflict but that
must be done later in decl_attributes since we are called
before attributes are assigned. */
- if (DECL_SECTION_NAME (newdecl) == NULL_TREE)
- DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl);
+ if ((DECL_EXTERNAL (olddecl) || TREE_PUBLIC (olddecl) || TREE_STATIC
(olddecl))
+ && DECL_SECTION_NAME (newdecl) == NULL_TREE
+ && DECL_SECTION_NAME (olddecl))
+ set_decl_section_name (newdecl, DECL_SECTION_NAME (olddecl));
/* Copy the assembler name.
Currently, it can only be defined in the prototype. */
@@ -2574,6 +2576,13 @@ duplicate_decls (tree newdecl, tree olddecl)
merge_decls (newdecl, olddecl, newtype, oldtype);
/* The NEWDECL will no longer be needed. */
+ if (TREE_CODE (newdecl) == FUNCTION_DECL
+ || TREE_CODE (newdecl) == VAR_DECL)
+ {
+ struct symtab_node *snode = symtab_get_node (newdecl);
+ if (snode)
+ symtab_remove_node (snode);
+ }
[...]
The related operation:
root@gchen:/upstream/linux# cat elevator.i
extern int __attribute__ ((__section__(".init.text"))) elv_register(void)
{
return 0;
}
extern typeof(elv_register) elv_register;
root@gchen:/upstream/linux# /usr/local/libexec/gcc/score-elf/4.10.0/cc1
elevator.i
elv_register
Analyzing compilation unit
Segmentation fault (core dumped)
root@gchen:/upstream/linux# /usr/local/bin/score-elf-gcc -v
Using built-in specs.
COLLECT_GCC=/usr/local/bin/score-elf-gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/score-elf/4.10.0/lto-wrapper
Target: score-elf
Configured with: ../gcc/configure --without-header --disable-nls
--enable-language=c --disable-threads --disable-shared --enable-werror=no
target_configargs=enable_vtable_verify=yes --target=score-elf --enable-obsolete
: (reconfigured) ../gcc/configure --without-header --disable-nls
--enable-language=c --disable-threads --disable-shared --enable-werror=no
target_configargs=enable_vtable_verify=yes --target=score-elf --enable-obsolete
--enable-debug --disable-release
Thread model: single
gcc version 4.10.0 20140625 (experimental) (GCC)
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
