let $$vars work even with unsupported c types (e.g., funkytown floats)

2 files changed, 42 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index ffee57ea..d96c848a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2008-08-11  Frank Ch. Eigler  <fche@elastic.org>
 
+	* tapsets.cxx (translate_final_fetch_or_store): Reject some
+	unhandleable types such as floats.
+	(dwarf_var...visit_target_symbol): Tweak logic of $$var expansion
+	to quietly skip over any $context variables that cause exceptions.
+
+2008-08-11  Frank Ch. Eigler  <fche@elastic.org>
+
 	* tapsets.cxx (dwarf_var_expanding...visit_target_symbol):
 	Don't add a \n at the end of $$vars/$$parms/$$locals.
 
diff --git a/tapsets.cxx b/tapsets.cxx
index 73a104b4..b35bc338 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -2060,6 +2060,33 @@ struct dwflpp
 
       case DW_TAG_enumeration_type:
       case DW_TAG_base_type:
+
+        // Reject types we can't handle in systemtap
+        {
+          dname = dwarf_diename(die);
+          diestr = (dname != NULL) ? dname : "<unknown>";
+
+          Dwarf_Attribute encoding_attr;
+          Dwarf_Word encoding = -1;
+          dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding, &encoding_attr),
+                           & encoding);
+          if (encoding < 0)
+            {
+              // clog << "bad type1 " << encoding << " diestr" << endl;
+              throw semantic_error ("unsupported type (mystery encoding " + lex_cast<string>(encoding) + ")" +
+                                    " for " + diestr);
+            }
+
+          if (encoding == DW_ATE_float
+              || encoding == DW_ATE_complex_float
+              /* XXX || many others? */)
+            {
+              // clog << "bad type " << encoding << " diestr" << endl;
+              throw semantic_error ("unsupported type (encoding " + lex_cast<string>(encoding) + ")" +
+                                    " for " + diestr);
+            }
+        }
+
 	ty = pe_long;
 	if (lvalue)
 	  c_translate_store (pool, 1, module_bias, die, typedie, tail,
@@ -2198,7 +2225,6 @@ struct dwflpp
       throw semantic_error("failed to retrieve type "
 			   "attribute for local '" + local + "'");
 
-
     /* Translate the ->bar->baz[NN] parts. */
 
     Dwarf_Die die_mem, *die = NULL;
@@ -4309,24 +4335,16 @@ dwarf_var_expanding_copy_visitor::visit_target_symbol (target_symbol *e)
 	    tsym->tok = sym_tok;
 	    tsym->base_name = "$";
 	    tsym->base_name += diename;
-	    Dwarf_Attribute attr_mem;
 
 	    // Ignore any variable that isn't accessible.
-	    // dwarf_attr_integrate is checked by literal_stmt_for_local
-	    // dwarf_getlocation_addr is checked by translate_location
-	    // but if those fail we cannot catch semantic_error.
-	    if (dwarf_attr_integrate (&result, DW_AT_location, &attr_mem) != NULL)
-	      {
-		Dwarf_Op *expr;
-		size_t len;
-		if (dwarf_getlocation_addr (&attr_mem, addr - q.dw.module_bias,
-					    &expr, &len, 1) == 0)
-		  continue;
-		this->visit_target_symbol(tsym);
-		pf->raw_components += diename;
-		pf->raw_components += "=%#x ";
-		pf->args.push_back(*(expression**)this->targets.top());
-	      }
+            tsym->saved_conversion_error = 0;
+            this->visit_target_symbol(tsym); // NB: throws nothing ...
+            if (! tsym->saved_conversion_error) // ... but this is how we know it happened.
+              {
+                pf->raw_components += diename;
+                pf->raw_components += "=%#x ";
+                pf->args.push_back(*(expression**)this->targets.top());
+              }
 	  }
 	while (dwarf_siblingof (&result, &result) == 0);