libdemangle-msvc: use MSVC demangler in GDB

This is the fourth in a series of patches adding MSVC symbol demangling
support to the GNU toolchain.

Register the MSVC demangler via bfd_set_msvc_demangler() in
gdb_bfd_init(), guarded by HAVE_MSVC_DEMANGLER.  Update cp-support.c
to handle MSVC-mangled names in GDB's symbol processing.  Link GDB
against libdemangle-msvc when enabled.

Author: Vladimir Uzelac

gdb/Makefile.in

@@ -160,6 +160,9 @@ INCLUDE_CFLAGS = -I$(INCLUDE_DIR)
 # Where is the "-liberty" library?  Typically in ../libiberty.
 LIBIBERTY = ../libiberty/libiberty.a
 
+# Where is the libdemangle-msvc library? Typically in ../libdemangle-msvc.
+LIBDEMANGLE_MSVC = ../libdemangle-msvc/libdemangle-msvc.a
+
 # Where is the CTF library?  Typically in ../libctf.
 LIBCTF = @LIBCTF@
 CTF_DEPS = @CTF_DEPS@
@@ -677,10 +680,11 @@ CLIBS = $(SIM) $(READLINE) $(OPCODES) $(LIBCTF) $(BFD) $(ZLIB) $(ZSTD_LIBS) \
 	$(LIBEXPAT) $(LIBLZMA) $(LIBIPT) \
 	$(WIN32LIBS) $(LIBGNU) $(LIBGNU_EXTRA_LIBS) $(LIBICONV) \
 	$(GMPLIBS) $(SRCHIGH_LIBS) $(LIBXXHASH) $(PTHREAD_LIBS) \
-	$(DEBUGINFOD_LIBS)
+	$(DEBUGINFOD_LIBS) $(LIBDEMANGLE_MSVC) 
+
 CDEPS = $(NAT_CDEPS) $(SIM) $(BFD) $(READLINE_DEPS) $(CTF_DEPS) \
 	$(OPCODES) $(INTL_DEPS) $(LIBIBERTY) $(CONFIG_DEPS) $(LIBGNU) \
-	$(LIBSUPPORT)
+	$(LIBSUPPORT) $(LIBDEMANGLE_MSVC)
 
 DIST = gdb
 

gdb/cp-support.c

@@ -730,6 +730,12 @@ cp_class_name_from_physname (const char *physname)
   std::unique_ptr<demangle_parse_info> info;
   int done;
 
+#ifdef HAVE_MSVC_DEMANGLER
+  char *msvc_result = msvc_class_name_from_physname (physname);
+  if (msvc_result != NULL)
+    return msvc_result;
+#endif
+
   info = mangled_name_to_comp (physname, DMGL_ANSI,
 			       &storage, &demangled_name);
   if (info == NULL)
@@ -876,6 +882,12 @@ method_name_from_physname (const char *physname)
   struct demangle_component *ret_comp;
   std::unique_ptr<demangle_parse_info> info;
 
+#ifdef HAVE_MSVC_DEMANGLER
+  char *msvc_result = msvc_method_name_from_physname (physname);
+  if (msvc_result != NULL)
+    return msvc_result;
+#endif
+
   info = mangled_name_to_comp (physname, DMGL_ANSI,
 			       &storage, &demangled_name);
   if (info == NULL)
@@ -1652,7 +1664,7 @@ gdb_demangle (const char *name, int options)
 #endif
 
   if (crash_signal == 0)
-    result.reset (bfd_demangle (NULL, name, options | DMGL_VERBOSE));
+    result.reset (bfd_demangle (nullptr, name, options | DMGL_VERBOSE));
 
 #ifdef HAVE_WORKING_FORK
   if (catch_demangler_crashes)

gdb/gdb_bfd.c

@@ -36,6 +36,9 @@
 #include "gdbsupport/cxx-thread.h"
 #include "gdbsupport/unordered_map.h"
 #include "gdbsupport/unordered_set.h"
+#ifdef HAVE_MSVC_DEMANGLER
+#include "demangle.h"
+#endif
 
 /* Lock held when doing BFD operations.  A recursive mutex is used
    because we use this mutex internally and also for BFD, just to make
@@ -1298,7 +1301,12 @@ gdb_bfd_init ()
   if (bfd_init () == BFD_INIT_MAGIC)
     {
       if (bfd_thread_init (gdb_bfd_lock, gdb_bfd_unlock, nullptr))
-	return;
+	{
+#ifdef HAVE_MSVC_DEMANGLER
+	  bfd_set_msvc_demangler (msvc_demangle);
+#endif
+	  return;
+	}
     }
 
   error (_("fatal error: libbfd ABI mismatch"));