From 107905919e3ede0f57017d3c6bf309fa44910ba6 Mon Sep 17 00:00:00 2001
From: Arne Döring <arne.doering@gmx.net>
Date: Mon, 15 Apr 2019 08:25:21 +0200
Subject: $ command in gdb now works (#10956)

---
 tools/nim-gdb.py | 47 +++++++++++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 10 deletions(-)

diff --git a/tools/nim-gdb.py b/tools/nim-gdb.py
index c1c2e0004..7804ad6e5 100644
--- a/tools/nim-gdb.py
+++ b/tools/nim-gdb.py
@@ -125,27 +125,36 @@ class NimTypePrinter:
 class DollarPrintFunction (gdb.Function):
   "Nim's equivalent of $ operator as a gdb function, available in expressions `print $dollar(myvalue)"
 
-  _gdb_dollar_functions = gdb.execute("info functions dollar__", True, True)
-  dollar_functions = re.findall('NimStringDesc \*(dollar__[A-z0-9_]+?)\(([^,)]*)\);', _gdb_dollar_functions)
+  dollar_functions = re.findall(
+    'NimStringDesc \*(dollar__[A-z0-9_]+?)\(([^,)]*)\);',
+    gdb.execute("info functions dollar__", True, True)
+  )
 
   def __init__ (self):
     super (DollarPrintFunction, self).__init__("dollar")
 
+
   @staticmethod
   def invoke_static(arg):
 
-    for func, arg_typ in DollarPrintFunction.dollar_functions:
+    if arg.type.code == gdb.TYPE_CODE_PTR and arg.type.target().name == "NimStringDesc":
+      return arg
 
-      if arg.type.name == arg_typ:
+    argTypeName = str(arg.type)
+
+    for func, arg_typ in DollarPrintFunction.dollar_functions:
+      # this way of overload resolution cannot deal with type aliases,
+      # therefore it won't find all overloads.
+      if arg_typ == argTypeName:
         func_value = gdb.lookup_global_symbol(func, gdb.SYMBOL_FUNCTIONS_DOMAIN).value()
         return func_value(arg)
 
-      if arg.type.name + " *" == arg_typ:
+      elif arg_typ == argTypeName + " *":
         func_value = gdb.lookup_global_symbol(func, gdb.SYMBOL_FUNCTIONS_DOMAIN).value()
         return func_value(arg.address)
 
-    typeName = arg.type.name
-    printErrorOnce(typeName, "No suitable Nim $ operator found for type: " + typeName + ".\n")
+    printErrorOnce(argTypeName, "No suitable Nim $ operator found for type: " + argTypeName + "\n")
+    return None
 
   def invoke(self, arg):
     return self.invoke_static(arg)
@@ -157,14 +166,32 @@ DollarPrintFunction()
 ################################################################################
 
 class DollarPrintCmd (gdb.Command):
-  """Dollar print command for Nim, `$ expr` will invoke Nim's $ operator"""
+  """Dollar print command for Nim, `$ expr` will invoke Nim's $ operator and print the result."""
 
   def __init__ (self):
     super (DollarPrintCmd, self).__init__ ("$", gdb.COMMAND_DATA, gdb.COMPLETE_EXPRESSION)
 
-  def invoke (self, arg, from_tty):
+  def invoke(self, arg, from_tty):
     param = gdb.parse_and_eval(arg)
-    gdb.write(str(DollarPrintFunction.invoke_static(param)) + "\n", gdb.STDOUT)
+    strValue = DollarPrintFunction.invoke_static(param)
+    if strValue:
+      gdb.write(
+        NimStringPrinter(strValue).to_string() + "\n",
+        gdb.STDOUT
+      )
+
+    # could not find a suitable dollar overload. This here is the
+    # fallback to get sensible output of basic types anyway.
+
+    elif param.type.code == gdb.TYPE_CODE_ARRAY and param.type.target().name == "char":
+      gdb.write(param.string("utf-8", "ignore") + "\n", gdb.STDOUT)
+    elif param.type.code == gdb.TYPE_CODE_INT:
+      gdb.write(str(int(param)) + "\n", gdb.STDOUT)
+    elif param.type.name == "NIM_BOOL":
+      if int(param) != 0:
+        gdb.write("true\n", gdb.STDOUT)
+      else:
+        gdb.write("false\n", gdb.STDOUT)
 
 DollarPrintCmd()
 
-- 
cgit 1.4.1-2-gfad0