From cbfbbf6996cbe3b9fe57ac2014aa7262bb6890d6 Mon Sep 17 00:00:00 2001
From: fche <fche>
Date: Tue, 24 Jan 2006 17:58:02 +0000
Subject: 2006-01-24  Frank Ch. Eigler  <fche@elastic.org>

	PR 2060 etc.
	* tapsets.cxx (visit_target_symbol): Tolerate failed resolution by
	letting target_symbol instance pass through to optimizer and
	type checker.
	* elaborate.cxx (semantic_pass_optimize): New family of functions and
	associated visitor classes.
	(visit_for_loop): Tolerate absent init/incr clauses.
	(semantic_pass): Invoke unless unoptimized (-u) option given.
	* main.cxx, session.h: Add support for flag.
	* staptree.cxx (visit_for_loop): Tolerate absent init/incr clauses.
	(traversing_visitor::visit_arrayindex): Visit the index expressions.
	(functioncall_traversing_visitor): New class.
	(varuse_tracking_visitor): New class.
	* staptree.h: Corresponding changes.
	* parse.cxx (parse_for_loop): Represent absent init/incr expressions
	with null statement pointer instead of optimized-out dummy numbers.
	* stap.1.in: Document optimization.
	* testsuite/{semko,transko}/*.stp: Added "-u" or other code to many
	tests to check bad code without optimizer elision.
	* testsuite/semok/optimize.stp: New test.

	* elaborate.cxx (unresolved, invalid, mismatch): Standardize error
	message wording.
	* stapfuncs.5.in: Tweak print/printf docs.
	* tapset/logging.stp: Remove redundant "print" auxiliary function,
	since it's a translator built-in.
	* testsuite/transok/five.stp: Extend test.
	* translate.cxx (emit_symbol_data): Put symbol table into a separate
	temporary header file, to make "-p3" output easier on the eyes.
	* buildrun.cxx (compile_pass): Eliminate test-mode support throughout.
	* main.cxx, session.h, translate.cxx: Ditto.
	* main.cxx (main): For last-pass=2 runs, print post-optimization ASTs.
---
 tapsets.cxx | 83 ++++++++++++++++++++++++++++++++-----------------------------
 1 file changed, 44 insertions(+), 39 deletions(-)

(limited to 'tapsets.cxx')

diff --git a/tapsets.cxx b/tapsets.cxx
index 7d10ddf3..89201cb2 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -1868,46 +1868,48 @@ target_variable_flavour_calculating_visitor::visit_target_symbol (target_symbol
 {
   assert(e->base_name.size() > 0 && e->base_name[0] == '$');
 
-  try
+  // NB: if for whatever reason this variable does not resolve,
+  // or is illegally used (write in non-guru mode for instance),
+  // just pretend that it's OK anyway.  var_expanding_copy_visitor
+  // will take care of throwing the appropriate exception.
+  
+  bool lvalue = is_active_lvalue(e);
+  flavour += lvalue ? 'w' : 'r';
+  exp_type ty;
+  string expr;
+  try 
     {
-      bool lvalue = is_active_lvalue(e);
-      if (lvalue && !q.sess.guru_mode)
-	throw semantic_error("Writing to target variable outside of guru mode", e->tok);
-
-      flavour += lvalue ? 'w' : 'r';
-      exp_type ty;
-      string expr = q.dw.literal_stmt_for_local(scope_die,
-						addr,
-						e->base_name.substr(1),
-						e->components,
-						lvalue,
-						ty);
-      switch (ty)
-	{
-	case pe_unknown:
-	  flavour += 'U';
-	  break;
-	case pe_long:
-	  flavour += 'L';
-	  break;
-	case pe_string:
-	  flavour += 'S';
-	  break;
-	case pe_stats:
-	  flavour += 'T';
-	  break;
-	}
-      flavour += lex_cast<string>(expr.size());
-      flavour += '{';
-      flavour += expr;
-      flavour += '}';
+      expr = q.dw.literal_stmt_for_local(scope_die,
+                                         addr,
+                                         e->base_name.substr(1),
+                                         e->components,
+                                         lvalue,
+                                         ty);
     }
-  catch (const semantic_error& er)
+  catch (const semantic_error& e)
     {
-      semantic_error er2 (er);
-      er2.tok1 = e->tok;
-      q.sess.print_error (er2);
+      ty = pe_unknown;
     }
+  
+  switch (ty)
+    {
+    case pe_unknown:
+      flavour += 'U';
+      break;
+    case pe_long:
+      flavour += 'L';
+      break;
+    case pe_string:
+      flavour += 'S';
+      break;
+    case pe_stats:
+      flavour += 'T';
+      break;
+    }
+  flavour += lex_cast<string>(expr.size());
+  flavour += '{';
+  flavour += expr;
+  flavour += '}';
 }
 
 
@@ -2636,9 +2638,12 @@ var_expanding_copy_visitor::visit_target_symbol (target_symbol *e)
     }
   catch (const semantic_error& er)
     {
-      // No need to be verbose: the flavour-gathering visitor
-      // already printed a message for this exact case.
-      throw semantic_error ("due to failed target variable resolution");
+      // We suppress this error message, and pass the unresolved
+      // target_symbol to the next pass.  We hope that this value ends
+      // up not being referenced after all, so it can be optimized out
+      // quietly.
+      provide <target_symbol*> (this, e);
+      return;
     }
 
   fdecl->name = fname;
-- 
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