The libbacktrace symbol table code was incorrectly discarding global
Mach-O symbols. This patch fixes the problem. Tested on macOS on the
compile farm, and also on x86_64-pc-linux-gnu. Committed to mainline.
Ian
For PR libbacktrace/97082
* macho.c (MACH_O_N_EXT): Don't define.
(MACH_O_N_UNDF): Define.
(macho_defined_symbol): Don't discard N_EXT symbols. Do
discard N_UNDF symbols.
af827b2ab90b9d726c7182c41fa2409005909db8
diff --git a/libbacktrace/macho.c b/libbacktrace/macho.c
index 5ceff05b29a..8f768f14a57 100644
--- a/libbacktrace/macho.c
+++ b/libbacktrace/macho.c
@@ -271,12 +271,14 @@ struct macho_nlist_64
/* Value found in nlist n_type field. */
-#define MACH_O_N_EXT 0x01 /* Extern symbol */
+#define MACH_O_N_STAB 0xe0 /* Stabs debugging symbol */
+#define MACH_O_N_TYPE 0x0e /* Mask for type bits */
+
+/* Values found after masking with MACH_O_N_TYPE. */
+#define MACH_O_N_UNDF 0x00 /* Undefined symbol */
#define MACH_O_N_ABS 0x02 /* Absolute symbol */
-#define MACH_O_N_SECT 0x0e /* Defined in section */
+#define MACH_O_N_SECT 0x0e /* Defined in section from n_sect field */
-#define MACH_O_N_TYPE 0x0e /* Mask for type bits */
-#define MACH_O_N_STAB 0xe0 /* Stabs debugging symbol */
/* Information we keep for a Mach-O symbol. */
@@ -492,10 +494,10 @@ macho_defined_symbol (uint8_t type)
{
if ((type & MACH_O_N_STAB) != 0)
return 0;
- if ((type & MACH_O_N_EXT) != 0)
- return 0;
switch (type & MACH_O_N_TYPE)
{
+ case MACH_O_N_UNDF:
+ return 0;
case MACH_O_N_ABS:
return 1;
case MACH_O_N_SECT:
