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* fixed endless loop with web bug #1571 (merged)

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This commit is contained in:
Jonas Maebe 2001-08-01 09:46:55 +00:00
parent 68ed130f45
commit 64f266bf07
1 changed files with 24 additions and 8 deletions
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32
compiler/i386/popt386.pas
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@ -434,7 +434,7 @@ Var
End;
End;
Procedure GetFinalDestination(AsmL: TAAsmOutput; hp: Taicpu);
function GetFinalDestination(AsmL: TAAsmOutput; hp: Taicpu; level: longint): boolean;
{traces sucessive jumps to their final destination and sets it, e.g.
je l1 je l3
<code> <code>
@ -442,7 +442,10 @@ Var
je l2 je l3
<code> <code>
l2: l2:
jmp l3 jmp l3}
jmp l3 jmp l3
the level parameter denotes how deeep we have already followed the jump,
to avoid endless loops with constructs such as "l5: ; jmp l5" }
Var p1, p2: Tai;
l: tasmlabel;
@ -462,6 +465,9 @@ Var
End;
Begin
if level > 20 then
exit;
GetfinalDestination := false;
If (tasmlabel(hp.oper[0].sym).labelnr >= LoLab) and
(tasmlabel(hp.oper[0].sym).labelnr <= HiLab) and {range check, a jump can go past an assembler block!}
Assigned(LTable^[tasmlabel(hp.oper[0].sym).labelnr-LoLab].TaiObj) Then
@ -485,7 +491,12 @@ Var
(Taicpu(p2).condition in [C_None,hp.condition]) and
SkipLabels(p1,p1)) Then
Begin
GetFinalDestination(asml, Taicpu(p1));
{ quick check for loops of the form "l5: ; jmp l5 }
if (tasmlabel(Taicpu(p1).oper[0].sym).labelnr =
tasmlabel(hp.oper[0].sym).labelnr) then
exit;
if not GetFinalDestination(asml, Taicpu(p1),succ(level)) then
exit;
Dec(tasmlabel(hp.oper[0].sym).refs);
hp.oper[0].sym:=Taicpu(p1).oper[0].sym;
inc(tasmlabel(hp.oper[0].sym).refs);
@ -516,9 +527,11 @@ Var
{$endif finaldestdebug}
inc(l.refs);
hp.oper[0].sym := l;
GetFinalDestination(asml, hp);
if not GetFinalDestination(asml, hp,succ(level)) then
exit;
end;
End;
GetFinalDestination := true;
End;
Function DoSubAddOpt(var p: Tai): Boolean;
@ -617,7 +630,7 @@ Begin
else
begin
If (LabDif <> 0) Then
GetFinalDestination(asml, Taicpu(p));
GetFinalDestination(asml, Taicpu(p),0);
p:=Tai(p.next);
continue;
end;
@ -627,11 +640,11 @@ Begin
asml.remove(hp1);
hp1.free;
If (LabDif <> 0) Then
GetFinalDestination(asml, Taicpu(p));
GetFinalDestination(asml, Taicpu(p),0);
end
else
If (LabDif <> 0) Then
GetFinalDestination(asml, Taicpu(p));
GetFinalDestination(asml, Taicpu(p),0);
end;
end;
end
@ -2008,7 +2021,10 @@ End.
{
$Log$
Revision 1.13 2001-04-13 01:22:19 peter
Revision 1.14 2001-08-01 09:46:55 jonas
* fixed endless loop with web bug 1571 (merged)
Revision 1.13 2001/04/13 01:22:19 peter
* symtable change to classes
* range check generation and errors fixed, make cycle DEBUG=1 works
* memory leaks fixed