Read thunk symbols from PDB debug info

Author: ssbssa

gdb/amd64-windows-tdep.c

@@ -1245,7 +1245,8 @@ amd64_windows_skip_trampoline_code (frame_info_ptr frame, CORE_ADDR pc)
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 
   /* Check for jmp *<offset>(%rip) (jump near, absolute indirect (/4)).  */
-  if (pc && read_memory_unsigned_integer (pc, 2, byte_order) == 0x25ff)
+  unsigned instr = pc ? read_memory_unsigned_integer (pc, 2, byte_order) : 0;
+  if (instr == 0x25ff)
     {
       /* Get opcode offset and see if we can find a reference in our data.  */
       ULONGEST offset
@@ -1264,8 +1265,26 @@ amd64_windows_skip_trampoline_code (frame_info_ptr frame, CORE_ADDR pc)
 	{
 	  if (startswith (symname, "__imp_")
 	      || startswith (symname, "_imp_"))
-	    destination
-	      = read_memory_unsigned_integer (indirect_addr, 8, byte_order);
+	    {
+	      destination
+		= read_memory_unsigned_integer (indirect_addr, 8, byte_order);
+
+	      pc = destination;
+	      instr = pc ? read_memory_unsigned_integer (pc, 2, byte_order) : 0;
+	    }
+	}
+    }
+
+  if ((instr & 0xff) == 0xe9)
+    {
+      struct minimal_symbol *sym = lookup_minimal_symbol_by_pc (pc).minsym;
+      const char *symname = sym ? sym->linkage_name () : NULL;
+
+      if (symname && startswith (symname, "__thunk_"))
+	{
+	  ULONGEST offset
+	    = read_memory_unsigned_integer (pc + 1, 4, byte_order);
+	  destination = pc + offset + 5;
 	}
     }
 

gdb/i386-windows-tdep.c

@@ -93,7 +93,29 @@ static int i386_windows_gregset_reg_offset[] =
 static CORE_ADDR
 i386_windows_skip_trampoline_code (frame_info_ptr frame, CORE_ADDR pc)
 {
-  return i386_pe_skip_trampoline_code (frame, pc, NULL);
+  CORE_ADDR addr = i386_pe_skip_trampoline_code (frame, pc, NULL);
+  if (addr != 0)
+    pc = addr;
+  if (pc != 0)
+    {
+      struct gdbarch *gdbarch = get_frame_arch (frame);
+      enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+      if (read_memory_unsigned_integer (pc, 1, byte_order) == 0xe9)
+	{
+	  struct minimal_symbol *sym = lookup_minimal_symbol_by_pc (pc).minsym;
+	  const char *symname = sym ? sym->linkage_name () : NULL;
+
+	  if (symname && (startswith (symname, "__thunk_")
+			  || startswith (symname, "_thunk_")))
+	    {
+	      ULONGEST offset
+		= read_memory_unsigned_integer (pc + 1, 4, byte_order);
+	      return pc + offset + 5;
+	    }
+	}
+    }
+  return addr;
 }
 
 static const char *

gdb/windows-nat.c

@@ -4321,6 +4321,27 @@ static BOOL CALLBACK symbol_callback (PSYMBOL_INFO si,
 
       pli->functions.push_back (sym);
     }
+  else if (si->Tag == SymTagThunk)
+    {
+      if (si->Flags & SYMFLAG_THUNK)
+	{
+	  ULONGEST val = si->Value + base_ofs;
+
+	  for (symbol *sym : pli->functions)
+	    {
+	      if (sym->value_block ()->start () == val)
+		{
+		  std::string imp_name
+		    = string_printf ("__thunk_%s", sym->linkage_name ());
+		  struct minimal_symbol *msym = pli->reader->record_full
+		    (imp_name.c_str (), true, unrelocated_addr (si->Address),
+		     mst_data, 0);
+		  if (msym)
+		    msym->set_size (si->Size);
+		}
+	    }
+	}
+    }
   else if (si->Tag == SymTagPublicSymbol)
     {
       struct minimal_symbol *msym = pli->reader->record_full