On Tue, 2009-08-18 at 08:43 -0700, Richard Henderson wrote:
> On 08/17/2009 07:40 PM, Jerry Quinn wrote:
> > On Mon, 2009-08-17 at 16:16 -0400, Jason Merrill wrote:
> >> I'm not sure why GCC sources would need to mangle function-local
> >> structs, though.
> >
> Would it be helpful to reserve a leading character (say, "*") that means
> that strcmp should not apply, but rather pointer identity? Thus a class
> foo that is intended to be local, as opposed to forced local via
> RTLD_LOCAL, can just use "*foo" and not have to bother with mangling?
I took a (very naive) swing at implementing this. I made the change in
my copy of r149964 to avoid the possibility of other issues interfering.
Apparently my change is too naive, because the assembler doesn't like a
name with '*' in it. Are there any chars that can pass muster with
assemblers but not be a valid namespace identifier?
The patch I tried is below.
Thanks,
Jerry
libtool: compile: /home/jlquinn/gcc/dev/build/trunk/./gcc/xgcc
-shared-libgcc -B/home/jlquinn/gcc/dev/build/trunk/./gcc -nostdinc++
-L/home/jlquinn/gcc/dev/build/trunk/x86_64-unknown-linux-gnu/libstdc
++-v3/src
-L/home/jlquinn/gcc/dev/build/trunk/x86_64-unknown-linux-gnu/libstdc
++-v3/src/.libs -B/usr/local/x86_64-unknown-linux-gnu/bin/
-B/usr/local/x86_64-unknown-linux-gnu/lib/
-isystem /usr/local/x86_64-unknown-linux-gnu/include
-isystem /usr/local/x86_64-unknown-linux-gnu/sys-include
-I/home/jlquinn/gcc/dev/gcc-in-cxx/libstdc++-v3/../gcc
-I/home/jlquinn/gcc/dev/build/trunk/x86_64-unknown-linux-gnu/libstdc
++-v3/include/x86_64-unknown-linux-gnu
-I/home/jlquinn/gcc/dev/build/trunk/x86_64-unknown-linux-gnu/libstdc
++-v3/include -I/home/jlquinn/gcc/dev/gcc-in-cxx/libstdc++-v3/libsupc++
-fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections -g
-O2 -D_GNU_SOURCE -c ../../../../../gcc-in-cxx/libstdc++-v3/libsupc
++/eh_alloc.cc -fPIC -DPIC -o eh_alloc.o
/tmp/ccbRNQMb.s: Assembler messages:
/tmp/ccbRNQMb.s:1384: Error: unrecognized symbol type ""
/tmp/ccbRNQMb.s:1384: Error: junk at end of line, first unrecognized
character is `*'
/tmp/ccbRNQMb.s:1385: Error: expected comma after name `_ZN12' in .size
directive
/tmp/ccbRNQMb.s:1386: Error: invalid character '*' in mnemonic
make[5]: *** [eh_alloc.lo] Error 1
Index: gcc/cp/name-lookup.c
===================================================================
--- gcc/cp/name-lookup.c (revision 149964)
+++ gcc/cp/name-lookup.c (working copy)
@@ -69,7 +69,8 @@
{
/* The anonymous namespace has to have a unique name
if typeinfo objects are being compared by name. */
- anonymous_namespace_name = get_file_function_name ("N");
+ // anonymous_namespace_name = get_file_function_name ("N");
+ anonymous_namespace_name = get_identifier ("*cxx_anon_ns");
}
return anonymous_namespace_name;
}
Index: libstdc++-v3/libsupc++/tinfo2.cc
===================================================================
--- libstdc++-v3/libsupc++/tinfo2.cc (revision 149964)
+++ libstdc++-v3/libsupc++/tinfo2.cc (working copy)
@@ -37,7 +37,9 @@
#if __GXX_MERGED_TYPEINFO_NAMES
return name () < arg.name ();
#else
- return __builtin_strcmp (name (), arg.name ()) < 0;
+ return (name ()[0] == '*' && arg.name()[0] == '*')
+ ? name () < arg.name ()
+ : __builtin_strcmp (name (), arg.name ()) < 0;
#endif
}
Index: libstdc++-v3/libsupc++/typeinfo
===================================================================
--- libstdc++-v3/libsupc++/typeinfo (revision 149964)
+++ libstdc++-v3/libsupc++/typeinfo (working copy)
@@ -110,12 +110,15 @@
// we can run into cases where type_info names aren't merged,
// so we still need to do string comparison.
bool before(const type_info& __arg) const
- { return __builtin_strcmp (__name, __arg.__name) < 0; }
+ { return (__name[0] == '*' && __arg.__name[0] == '*')
+ ? __name < __arg.__name
+ : __builtin_strcmp (__name, __arg.__name) < 0; }
bool operator==(const type_info& __arg) const
{
return ((__name == __arg.__name)
- || __builtin_strcmp (__name, __arg.__name) == 0);
+ || (__name[0] != '*' && __arg.__name[0] != '*' &&
+ __builtin_strcmp (__name, __arg.__name) == 0));
}
#else
// On some targets we can rely on type_info's NTBS being unique,
Index: libstdc++-v3/libsupc++/tinfo.cc
===================================================================
--- libstdc++-v3/libsupc++/tinfo.cc (revision 149964)
+++ libstdc++-v3/libsupc++/tinfo.cc (working copy)
@@ -41,7 +41,9 @@
#if __GXX_MERGED_TYPEINFO_NAMES
return name () == arg.name ();
#else
- return (&arg == this) || (__builtin_strcmp (name (), arg.name ()) ==
0);
+ return (&arg == this)
+ || (name ()[0] != '*' && arg.name ()[0] != '*'
+ && (__builtin_strcmp (name (), arg.name ()) == 0));
#endif
}
