On Mon, Nov 18, 2013 at 09:09:03AM -0800, Ian Lance Taylor wrote:
> > 2) for tsan querying of data symbols, apparently the classes want to see
> > not just the symbol name and start value, but also size. libbacktrace
> > has all this info available, just doesn't pass it down to the callback.
> > I wonder if we'd need to create yet another libbacktrace entrypoint, or
> > if it would be acceptable to do source code incompatible, ABI (at least
> > on all sane targets) compatible version of just adding another
> > uintptr_t symsize argument to backtrace_syminfo_callback.
>
> I think it would be fine to change the callback. I doubt that
> libbacktrace is so widely used that we need to worry about backward
> compatibility at this stage. In particular I imagine that any users
> of libbacktrace are simply copying the source code, since there is no
> installable package.
So how about this? Due to the CLA etc. I have not done the obvious change
to libgo/runtime/go-caller.c (syminfo_callback) that is needed together with
that.
2013-11-19 Jakub Jelinek <ja...@redhat.com>
* backtrace.h (backtrace_syminfo_callback): Add symsize argument.
* elf.c (elf_syminfo): Pass 0 or sym->size to the callback as
last argument.
* btest.c (struct symdata): Add size field.
(callback_three): Add symsize argument. Copy it to the data->size
field.
(f23): Set symdata.size to 0.
(test5): Likewise. If sizeof (int) > 1, lookup address of
((uintptr_t) &global) + 1. Verify symdata.val and symdata.size
values.
--- libbacktrace/backtrace.h.jj 2013-11-18 09:59:08.000000000 +0100
+++ libbacktrace/backtrace.h 2013-11-19 08:46:32.537927858 +0100
@@ -169,12 +169,13 @@ extern int backtrace_pcinfo (struct back
/* The type of the callback argument to backtrace_syminfo. DATA and
PC are the arguments passed to backtrace_syminfo. SYMNAME is the
name of the symbol for the corresponding code. SYMVAL is the
- value. SYMNAME will be NULL if no error occurred but the symbol
- could not be found. */
+ value and SYMSIZE is the size of the symbol. SYMNAME will be NULL
+ if no error occurred but the symbol could not be found. */
typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc,
const char *symname,
- uintptr_t symval);
+ uintptr_t symval,
+ uintptr_t symsize);
/* Given ADDR, an address or program counter in the current program,
call the callback information with the symbol name and value
--- libbacktrace/elf.c.jj 2013-11-19 08:35:09.000000000 +0100
+++ libbacktrace/elf.c 2013-11-19 08:47:37.646598147 +0100
@@ -502,9 +502,9 @@ elf_syminfo (struct backtrace_state *sta
}
if (sym == NULL)
- callback (data, addr, NULL, 0);
+ callback (data, addr, NULL, 0, 0);
else
- callback (data, addr, sym->name, sym->address);
+ callback (data, addr, sym->name, sym->address, sym->size);
}
/* Add the backtrace data for one ELF file. */
--- libbacktrace/btest.c.jj 2013-11-18 09:59:08.000000000 +0100
+++ libbacktrace/btest.c 2013-11-19 08:56:29.320901588 +0100
@@ -92,7 +92,7 @@ struct sdata
struct symdata
{
const char *name;
- uintptr_t val;
+ uintptr_t val, size;
int failed;
};
@@ -238,7 +238,8 @@ error_callback_two (void *vdata, const c
static void
callback_three (void *vdata, uintptr_t pc ATTRIBUTE_UNUSED,
- const char *symname, uintptr_t symval)
+ const char *symname, uintptr_t symval,
+ uintptr_t symsize)
{
struct symdata *data = (struct symdata *) vdata;
@@ -250,6 +251,7 @@ callback_three (void *vdata, uintptr_t p
assert (data->name != NULL);
}
data->val = symval;
+ data->size = symsize;
}
/* The backtrace_syminfo error callback function. */
@@ -458,6 +460,7 @@ f23 (int f1line, int f2line)
symdata.name = NULL;
symdata.val = 0;
+ symdata.size = 0;
symdata.failed = 0;
i = backtrace_syminfo (state, addrs[j], callback_three,
@@ -605,12 +608,17 @@ test5 (void)
{
struct symdata symdata;
int i;
+ uintptr_t addr = (uintptr_t) &global;
+
+ if (sizeof (global) > 1)
+ addr += 1;
symdata.name = NULL;
symdata.val = 0;
+ symdata.size = 0;
symdata.failed = 0;
- i = backtrace_syminfo (state, (uintptr_t) &global, callback_three,
+ i = backtrace_syminfo (state, addr, callback_three,
error_callback_three, &symdata);
if (i == 0)
{
@@ -634,6 +642,22 @@ test5 (void)
symdata.name, "global");
symdata.failed = 1;
}
+ else if (symdata.val != (uintptr_t) &global)
+ {
+ fprintf (stderr,
+ "test5: unexpected syminfo value got %lx expected %lx\n",
+ (unsigned long) symdata.val,
+ (unsigned long) (uintptr_t) &global);
+ symdata.failed = 1;
+ }
+ else if (symdata.size != sizeof (global))
+ {
+ fprintf (stderr,
+ "test5: unexpected syminfo size got %lx expected %lx\n",
+ (unsigned long) symdata.size,
+ (unsigned long) sizeof (global));
+ symdata.failed = 1;
+ }
}
printf ("%s: backtrace_syminfo variable\n",
Jakub
