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Tom de Vries 4343499695 [gdb] Fix catch throw regexp matching
When running test-case gdb.mi/mi-catch-cpp-exceptions.exp, we have:
...
FAIL: gdb.mi/mi-catch-cpp-exceptions.exp: all with invalid regexp: run until \
  breakpoint in main (unknown output after running)
...

This is a regression since commit 596dc4adff "Speed up psymbol reading by
removing a copy".

Before that commit, we have:
...
$ gdb \
    -batch \
    ./outputs/gdb.mi/mi-catch-cpp-exceptions/mi-catch-cpp-exceptions \
    -ex "break 67" \
    -ex "catch throw -r blahblah" \
    -ex r
Breakpoint 1 at 0x4008e5: file mi-catch-cpp-exceptions.cc, line 67.
Catchpoint 2 (throw)

Breakpoint 1, main () at mi-catch-cpp-exceptions.cc:67
67                  return 1;   /* Stop here.  */
...
In other words:
- we set a breakpoint somewhere in main,
- we set a catchpoint with a regexp that is intended to not match any
  exception, and
- run to the breakpoint, without the catchpoint triggering.

After the commit, we have:
...
$ gdb \
    -batch \
    ./outputs/gdb.mi/mi-catch-cpp-exceptions/mi-catch-cpp-exceptions \
    -ex "break 67" \
    -ex "catch throw -r blahblah" \
    -ex r
Breakpoint 1 at 0x4008e5: file mi-catch-cpp-exceptions.cc, line 67.
Catchpoint 2 (throw)

Catchpoint 2 (exception thrown), 0x00007ffff7ab037e in __cxa_throw () from \
  /usr/lib64/libstdc++.so.6
...
In other words, the catchpoint triggers.

This is caused by this bit of the commit:
...
       type_name = cplus_typename_from_type_info (typeinfo_arg);

       canon = cp_canonicalize_string (type_name.c_str ());
-      if (!canon.empty ())
-       std::swap (type_name, canon);
+      name = (canon == nullptr
+	      ? canon.get ()
+	      : type_name.c_str ());
     }
   catch (const gdb_exception_error &e)
     {
       exception_print (gdb_stderr, e);
     }

-  if (!type_name.empty ())
+  if (name != nullptr)
     {
-      if (self->pattern->exec (type_name.c_str (), 0, NULL, 0) != 0)
+      if (self->pattern->exec (name, 0, NULL, 0) != 0)
...

Before the commit, we have:
- type_name == "my_exception"
- canon = ""
and the !type_name.empty () test succeeds, and gdb executes the
self->pattern->exec call.

After the commit, we have:
- type_name == "my_exception"
- canon == NULL
- name == NULL
and the name != nullptr test fails, and gdb doesn't execute the
self->pattern->exec call.

Fix this by inverting the condition for the calculation of name:
...
-      name = (canon == nullptr
+      name = (canon != nullptr
...

Build and tested on x86_64-linux.

gdb/ChangeLog:

2020-05-09  Tom de Vries  <tdevries@suse.de>

	PR gdb/25955
	* break-catch-throw.c (check_status_exception_catchpoint): Fix name
	calculation.
2020-05-09 20:17:10 +02:00
bfd Automatic date update in version.in 2020-05-09 00:00:12 +00:00
binutils objcopy: Mention 'entry address' in description 2020-05-07 11:39:39 +01:00
config Sync config and libiberty with GCC 2020-04-29 14:25:36 -07:00
contrib
cpu cpu,gas,opcodes: support for eBPF JMP32 instruction class 2020-04-16 09:52:57 +02:00
elfcpp
etc
gas Updated Swedish translation for the gas sub-directory 2020-05-06 14:17:36 +01:00
gdb [gdb] Fix catch throw regexp matching 2020-05-09 20:17:10 +02:00
gdbserver Implement debugging of WOW64 processes in gdbserver 2020-04-30 18:30:20 +02:00
gdbsupport Fix typo (thead -> thread) 2020-04-28 11:38:26 +02:00
gnulib
gold gold: Compile common tests with -fcommon 2020-05-02 06:48:26 -07:00
gprof Updated French translation for the gprof sub-directory. 2020-05-07 10:48:21 +01:00
include AArch64: add GAS support for UDF instruction 2020-04-30 15:47:30 +01:00
intl
ld [binutils-gdb][ld][AArch64] Fix group_sections algorithm 2020-05-04 15:51:56 +01:00
libctf
libdecnumber
libiberty Sync config and libiberty with GCC 2020-04-29 14:25:36 -07:00
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ChangeLog Since the pdp11-aout target does not support gdb, gdbserver or gprof these should be excluded in configure. 2020-04-21 10:27:50 +01:00
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