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hand source: emit short-circuit and/or to fix self-hosting fixpoint

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EmitExpr for TBinaryExpr now checks for boAnd/boOr first and emits
short-circuit branches (jnz to sc_rhs/sc_end labels) before evaluating
either operand.  The eager `and` instruction previously emitted was
safe for bitwise use but caused a null-pointer crash when the compiler
compiled itself: TSymbolTable.FindType evaluated Sym.Kind even when Sym
was nil, because the code generator did not short-circuit the guard
`(Sym <> nil) and (Sym.Kind = skTypeAlias)`.

Stage-3 now produces byte-identical IR to stage-2 (fixpoint reached).
This commit is contained in:
Graeme Geldenhuys 2026-04-27 09:06:37 +01:00
parent 71b7fd5aae
commit 7a88335393
1 changed files with 23 additions and 8 deletions
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31
tests/blaise-compiler.pas
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@ -1903,7 +1903,7 @@ begin
case Kind of
tyInteger, tyUInt32, tyEnum: Result := 4;
tyInt64: Result := 8;
tyByte, tyBoolean: Result := 1;
tyByte, tyBoolean: Result := 4; { stored as word, same as AllocAlign }
tyString: Result := 8;
tyRecord: Result := TRecordTypeDesc(Self).TotalSize;
tyNil: Result := 8;
@ -10161,14 +10161,7 @@ begin
if AAssign.ObjExpr <> nil then
begin
PtrTemp := EmitExpr(AAssign.ObjExpr);
if AAssign.IsClassAccess then
begin
Ptr := AllocTemp;
EmitLine(Format(' %s =l loadl %s', Ptr, PtrTemp));
PtrTemp := Ptr;
end;
if AAssign.FieldInfo.Offset > 0 then
begin
Ptr := AllocTemp;
@ -12357,6 +12350,28 @@ begin
else if AExpr is TBinaryExpr then
begin
BinExpr := TBinaryExpr(AExpr);
if (BinExpr.Op = boAnd) or (BinExpr.Op = boOr) then
begin
SelfTemp := AllocTemp;
EmitLine(Format(' %s =l alloc4 1', SelfTemp));
L := EmitExpr(BinExpr.Left);
EmitLine(Format(' storew %s, %s', L, SelfTemp));
FuncName := AllocLabel('sc_rhs');
ArgLine := AllocLabel('sc_end');
if BinExpr.Op = boAnd then
EmitLine(Format(' jnz %s, @%s, @%s', L, FuncName, ArgLine))
else
EmitLine(Format(' jnz %s, @%s, @%s', L, ArgLine, FuncName));
EmitLine('@' + FuncName);
R := EmitExpr(BinExpr.Right);
EmitLine(Format(' storew %s, %s', R, SelfTemp));
EmitLine(Format(' jmp @%s', ArgLine));
EmitLine('@' + ArgLine);
T := AllocTemp;
EmitLine(Format(' %s =w loadw %s', T, SelfTemp));
Result := T;
Exit;
end;
L := EmitExpr(BinExpr.Left);
R := EmitExpr(BinExpr.Right);
T := AllocTemp;