[PATCH2 PR gdb/18071] aarch64: "info addr" command can't resolve TLS variables

[Weimin Pan]

Running the test case with upstream gdb shows two failures:

(1) Receiving different error messages when printing TLS variable before
    program runs - because the ARM compiler does not emit dwarf attribute
    DW_AT_location for TLS, the result is expected and the baseline may
    need to be changed for aarch64.

(2) Using "info address" command on C++ static TLS object resulted in
    "symbol unresolved" error - below is a snippet from the test case:

class K {
 public:
  static __thread int another_thread_local;
};

__thread int K::another_thread_local;

(gdb) info address K::another_thread_local
Symbol "K::another_thread_local" is unresolved.

This patch contains fix for (2).

Function info_address_command() handles the "info address" command and
calls lookup_minimal_symbol_and_objfile() to find sym's symbol entry in
minimal symbol table if SYMBOL_COMPUTED_OPS (sym) is false. Problem is
that function lookup_minimal_symbol_and_objfile() only looked up an
objfile's minsym ordinary hash table, not its demangled hash table, which
was the reason why the C++ name was not found.

The fix is to replace the lookup_minimal_symbol_and_objfile() call with
the lookup_bound_minimal_symbol() call, which looks up entries in both
minsym's hash tables, via lookup_minimal_symbol(), to find symbol entry 
that's associated with the demangled name.

Tested in both aarch64-linux-gnu and amd64-linux-gnu. No regressions.
---
 gdb/ChangeLog  |    8 ++++++++
 gdb/printcmd.c |    2 +-
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index fe4ae9f..5faa37b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2018-03-22  Weimin Pan  <weimin.pan@oracle.com>
+
+	PR gdb/18071:
+	* printcmd.c (info_address_command): Replace
+	lookup_minimal_symbol_and_objfile call with
+	lookup_bound_minimal_symbol call to find symbol entry
+	of a demangled name.
+
 2018-03-19  Pedro Alves  <palves@redhat.com>
 	    Tom Tromey  <tom@tromey.com>
 
diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index dd81d8f..06038cd 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -1564,7 +1564,7 @@ info_address_command (const char *exp, int from_tty)
       {
 	struct bound_minimal_symbol msym;
 
-	msym = lookup_minimal_symbol_and_objfile (SYMBOL_LINKAGE_NAME (sym));
+	msym = lookup_bound_minimal_symbol (SYMBOL_LINKAGE_NAME (sym));
 	if (msym.minsym == NULL)
 	  printf_filtered ("unresolved");
 	else
-- 
1.7.1