belated spring cleaning: imitate semantic_error chaining for macro feature

diff --git a/parse.cxx b/parse.cxx
index e22a310cb42aa9f1a2b3236e3e5ea81daab1fbbe..973c46bbde8c6159812663b8f3aa57574d98a854 100644 (file)
--- a/parse.cxx
+++ b/parse.cxx
@@ -438,12 +438,19 @@ parser::scan_pp1 ()
 
           // check for redefinition of existing macro
           if (pp1_namespace.find(name) != pp1_namespace.end())
-            // TODOXXX use a slightly different chaining hack to also point to
-            // pp1_namespace[name]->tok, the site of the original definition?
-            throw parse_error (_F("attempt to redefine macro '@%s' in the same file", name.c_str ()), t);
-          // XXX: this restriction was mostly necessary due to wanting
-          // to leave open the possibility of statically-scoped
-          // semantics in the future.
+            {
+              parse_error er (_F("attempt to redefine macro '@%s' in the same file", name.c_str ()), t);
+
+              // Also point to pp1_namespace[name]->tok, the site of
+              // the original definition:
+              er.chain = new parse_error (_F("macro '@%s' first defined here",
+                                             name.c_str()), pp1_namespace[name]->tok);
+              throw er;
+            }
+
+          // XXX: the above restriction was mostly necessary due to
+          // wanting to leave open the possibility of
+          // statically-scoped semantics in the future.
 
           // XXX: this cascades into further parse errors as the
           // parser tries to parse the remaining definition... (e.g.
@@ -712,13 +719,11 @@ parser::parse_library_macros ()
 
           if (session.library_macros.find(name) != session.library_macros.end())
             {
-              // XXX ugly hack simulates chaining
-              parse_error* er1 = new parse_error (_F("duplicate definition of library macro '%s'", name.c_str()), it->second->tok);
-              parse_error* er2 = new parse_error (_("location of original definition was"), session.library_macros[name]->tok);
-              print_error (*er1);
-              print_error (*er2);
-              delete er1; delete er2;
+              parse_error er(_F("duplicate definition of library macro '@%s'", name.c_str()), it->second->tok);
+              er.chain = new parse_error (_F("macro '@%s' first defined here", name.c_str()), session.library_macros[name]->tok);
+              print_error (er);
 
+              delete er.chain;
               delete f;
               return 0;
             }

diff --git a/session.cxx b/session.cxx
index 01a5f133b5b0848b994d88f358180f332bd824b2..6c392a11c5530323308a0ed4be85fc0696ee5167 100644 (file)
--- a/session.cxx
+++ b/session.cxx
@@ -2017,6 +2017,17 @@ systemtap_session::print_error (const parse_error &pe,
     cerr << _("\tin expansion of macro: ") << colorize(tok) << endl;
     print_error_source (cerr, align_parse_error, tok);
   }
+
+  // print other chained errors
+  if (pe.chain)
+    {
+      // NB: input_name is considered to be irrelevant for chained
+      // parse errors, since it is never used so long as pe.tok is
+      // well-defined; and a chained error MUST have a specified
+      // token:
+      assert (pe.tok);
+      print_error (* pe.chain, pe.tok, input_name);
+    }
 }
 
 void

diff --git a/session.h b/session.h
index d1a86382566b3bfa6da3957f521756ba1318f193..d7554bd2ed17cd9805d3ecb5f3ab0f3ad3f8a5fe 100644 (file)
--- a/session.h
+++ b/session.h
@@ -94,12 +94,13 @@ struct parse_error: public std::runtime_error
 {
   const token* tok;
   bool skip_some;
+  const parse_error *chain;
   parse_error (const std::string& msg):
-    runtime_error (msg), tok (0), skip_some (true) {}
+    runtime_error (msg), tok (0), skip_some (true), chain(0) {}
   parse_error (const std::string& msg, const token* t):
-    runtime_error (msg), tok (t), skip_some (true) {}
+    runtime_error (msg), tok (t), skip_some (true), chain(0) {}
   parse_error (const std::string& msg, bool skip):
-    runtime_error (msg), tok (0), skip_some (skip) {}
+    runtime_error (msg), tok (0), skip_some (skip), chain(0) {}
 };
 
 struct systemtap_session