Re: [RFA] minsyms.c: Fix switching to GNU v3 ABI

Corinna Vinschen
2004-03-26T13:57:31Z

On Mar 25 15:44, Jim Blandy wrote:
> One comment: I notice that we actually remove the leading character
> earlier in prim_record_minimal_symbol_and_info, to check if the name
> is the same as that of the GCC compilation marker symbol. It would be
> nicer if we could just remove the leading character once, at the top
> of the function, and then simplify the the "__gnu_compiled" test.
> Doing so shouldn't interfere with the GCC_COMPILED_FLAG_SYMBOL tests,
> since the code already presumes those both start with 'g'.

Well, it could interfere. Assuming that leading char is the underscore.
The first test would now find "gcc_compiled.", but not "_gcc_compiled.".
When skipping the leading char before testing, the same test would now
also find "_gcc_compiled.". If that's ok, I don't have a problem to
change it as you like. Otherwise, I'd propose the below patch, which
avoids that problem.

Corinna

* minsyms.c (install_minimal_symbols): Move dropping leading
char from linkage name from here...
(prim_record_minimal_symbol_and_info): ...to here. Simplify
test for "__gnu_compiled*" symbols.

Index: minsyms.c
===================================================================
RCS file: /cvs/src/src/gdb/minsyms.c,v
retrieving revision 1.41
diff -u -p -r1.41 minsyms.c
--- minsyms.c 9 Feb 2004 19:13:46 -0000 1.41
+++ minsyms.c 26 Mar 2004 11:28:46 -0000
@@ -580,26 +580,23 @@ prim_record_minimal_symbol_and_info (con
struct msym_bunch *new;
struct minimal_symbol *msymbol;

- if (ms_type == mst_file_text)
- {
- /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
- the minimal symbols, because if there is also another symbol
- at the same address (e.g. the first function of the file),
- lookup_minimal_symbol_by_pc would have no way of getting the
- right one. */
- if (name[0] == 'g'
- && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
- || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
- return (NULL);
-
- {
- const char *tempstring = name;
- if (tempstring[0] == get_symbol_leading_char (objfile->obfd))
- ++tempstring;
- if (strncmp (tempstring, "__gnu_compiled", 14) == 0)
- return (NULL);
- }
- }
+ /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
+ the minimal symbols, because if there is also another symbol
+ at the same address (e.g. the first function of the file),
+ lookup_minimal_symbol_by_pc would have no way of getting the
+ right one. */
+ if (ms_type == mst_file_text && name[0] == 'g'
+ && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
+ || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
+ return (NULL);
+
+ /* It's save to strip the leading char here once, since the name
+ is also stored stripped in the minimal symbol table. */
+ if (name[0] == get_symbol_leading_char (objfile->obfd))
+ ++name;
+
+ if (ms_type == mst_file_text && strncmp (name, "__gnu_compiled", 14) == 0)
+ return (NULL);

if (msym_bunch_index == BUNCH_SIZE)
{
@@ -831,7 +828,6 @@ install_minimal_symbols (struct objfile
struct msym_bunch *bunch;
struct minimal_symbol *msymbols;
int alloc_count;
- char leading_char;

if (msym_count > 0)
{
@@ -859,18 +855,11 @@ install_minimal_symbols (struct objfile
each bunch is full. */

mcount = objfile->minimal_symbol_count;
- leading_char = get_symbol_leading_char (objfile->obfd);

for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next)
{
for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
- {
- msymbols[mcount] = bunch->contents[bindex];
- if (SYMBOL_LINKAGE_NAME (&msymbols[mcount])[0] == leading_char)
- {
- SYMBOL_LINKAGE_NAME (&msymbols[mcount])++;
- }
- }
+ msymbols[mcount] = bunch->contents[bindex];
msym_bunch_index = BUNCH_SIZE;
}

--
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.