* proper handling of dummy result node in dfa, resolves #8717 and #8079

+ tests

git-svn-id: trunk@8147 -

.gitattributes

@@ -7374,6 +7374,7 @@ tests/webtbf/tw7989.pp svneol=native#text/plain
 tests/webtbf/tw7998.pp svneol=native#text/plain
 tests/webtbf/tw8019.pp svneol=native#text/plain
 tests/webtbf/tw8031.pp svneol=native#text/plain
+tests/webtbf/tw8079.pp svneol=native#text/plain
 tests/webtbf/tw8140a.pp svneol=native#text/plain
 tests/webtbf/tw8140c.pp svneol=native#text/plain
 tests/webtbf/tw8140d.pp svneol=native#text/plain
@@ -7392,6 +7393,7 @@ tests/webtbf/tw8528.pp svneol=native#text/plain
 tests/webtbf/tw8583.pp svneol=native#text/plain
 tests/webtbf/tw8588.pp svneol=native#text/plain
 tests/webtbf/tw8591.pp -text
+tests/webtbf/tw8717.pp svneol=native#text/plain
 tests/webtbf/tw8738.pas svneol=native#text/plain
 tests/webtbf/tw8777a.pp svneol=native#text/plain
 tests/webtbf/tw8777b.pp svneol=native#text/plain

compiler/optdfa.pas

@@ -31,13 +31,22 @@ unit optdfa;
   interface
 
     uses
-      node;
+      node,optutils;
 
-    { reset all dfa info, this is required before creating dfa info
-      if the tree has been changed without updating dfa }
-    procedure resetdfainfo(node : tnode);
+    type
+      TDFABuilder = class
+      protected
+        procedure CreateLifeInfo(node : tnode;map : TIndexedNodeSet);
+      public
+        resultnode : tnode;
+        nodemap : TIndexedNodeSet;
+        { reset all dfa info, this is required before creating dfa info
+          if the tree has been changed without updating dfa }
+        procedure resetdfainfo(node : tnode);
 
-    procedure createdfainfo(node : tnode);
+        procedure createdfainfo(node : tnode);
+        destructor destroy;override;
+      end;
 
   implementation
 
@@ -50,7 +59,7 @@ unit optdfa;
       procinfo,
       nutils,
       nbas,nflw,ncon,ninl,ncal,nset,
-      optbase,optutils;
+      optbase;
 
 
     (*
@@ -131,11 +140,10 @@ unit optdfa;
       end;
 
 
-    procedure CreateLifeInfo(node : tnode;map : TIndexedNodeSet);
+    procedure TDFABuilder.CreateLifeInfo(node : tnode;map : TIndexedNodeSet);
 
       var
         changed : boolean;
-        Resultnode : TNode;
 
       procedure CreateInfo(node : tnode);
 
@@ -484,26 +492,33 @@ unit optdfa;
 {$ifdef DEBUG_DFA}
         writeln('DFA solver iterations: ',runs);
 {$endif DEBUG_DFA}
-        resultnode.free;
       end;
 
 
     { reset all dfa info, this is required before creating dfa info
       if the tree has been changed without updating dfa }
-    procedure resetdfainfo(node : tnode);
+    procedure TDFABuilder.resetdfainfo(node : tnode);
       begin
       end;
 
 
-    procedure createdfainfo(node : tnode);
+    procedure TDFABuilder.createdfainfo(node : tnode);
       begin
-        if not(assigned(current_procinfo.nodemap)) then
-          current_procinfo.nodemap:=TIndexedNodeSet.Create;
+        if not(assigned(nodemap)) then
+          nodemap:=TIndexedNodeSet.Create;
         { add controll flow information }
         SetNodeSucessors(node);
 
         { now, collect life information }
-        CreateLifeInfo(node,current_procinfo.nodemap);
+        CreateLifeInfo(node,nodemap);
+      end;
+
+
+    destructor TDFABuilder.Destroy;
+      begin
+        Resultnode.free;
+        nodemap.free;
+        inherited destroy;
       end;
 
 end.

compiler/procinfo.pas

@@ -103,9 +103,6 @@ unit procinfo;
           { max. of space need for parameters }
           maxpushedparasize : aint;
 
-          { node to index mapping for the node level optimizer }
-          nodemap : TIndexedNodeSet;
-
           constructor create(aparent:tprocinfo);virtual;
           destructor destroy;override;
 

compiler/psub.pas

@@ -28,7 +28,7 @@ interface
     uses
       cclasses,globals,
       node,nbas,
-      symdef,procinfo;
+      symdef,procinfo,optdfa;
 
     type
       tcgprocinfo = class(tprocinfo)
@@ -46,6 +46,7 @@ interface
         final_asmnode : tasmnode;
         { list to store the procinfo's of the nested procedures }
         nestedprocs : tlinkedlist;
+        dfabuilder : TDFABuilder;
         constructor create(aparent:tprocinfo);override;
         destructor  destroy;override;
         procedure printproc;
@@ -105,7 +106,6 @@ implementation
        optbase,
        opttail,
        optcse,
-       optdfa,
        optutils
 {$if defined(arm) or defined(powerpc) or defined(powerpc64)}
        ,aasmcpu
@@ -771,18 +771,19 @@ implementation
                   pi_needs_implicit_finally,pi_has_implicit_finally,pi_has_stackparameter,
                   pi_needs_stackframe])=[]) then
           begin
-            createdfainfo(code);
+            dfabuilder:=TDFABuilder.Create;
+            dfabuilder.createdfainfo(code);
             { when life info is available, we can give more sophisticated warning about unintialized
               variables }
 
             { iterate through life info of the first node }
-            for i:=0 to nodemap.count-1 do
+            for i:=0 to dfabuilder.nodemap.count-1 do
               begin
                 if DFASetIn(code.optinfo^.life,i) then
-                  case tnode(nodemap[i]).nodetype of
+                  case tnode(dfabuilder.nodemap[i]).nodetype of
                     loadn:
                       begin
-                        varsym:=tabstractnormalvarsym(tloadnode(nodemap[i]).symtableentry);
+                        varsym:=tabstractnormalvarsym(tloadnode(dfabuilder.nodemap[i]).symtableentry);
 
                         { Give warning/note for living locals }
                         if assigned(varsym.owner) and
@@ -1100,6 +1101,8 @@ implementation
             tg:=nil;
           end;
 
+        dfabuilder.free;
+
         { restore symtablestack }
         remove_from_symtablestack;
 

tests/webtbf/tw8079.pp

@@ -0,0 +1,14 @@
+{ %opt=-vw -Sew -Oodfa }
+{ %fail }
+program test;
+
+function foo(x: integer): integer;
+begin
+  if x > 10 then
+    exit(10);
+end;
+
+begin
+  foo(4);
+  foo(12);
+end.

tests/webtbf/tw8717.pp

@@ -0,0 +1,11 @@
+{ %opt=-vw -Sew -Oodfa }
+{ %fail }
+{$mode objfpc}
+function f: Boolean;
+begin
+  Exit;
+  Result := True
+end;
+
+begin
+end.