mirror of
https://gitlab.com/freepascal.org/fpc/source.git
synced 2025-04-07 21:48:01 +02:00
9118146bc1
parameters:
1) since they are finalised on the caller side, if that same value
is passed as a value parameter as well and its reference count
was 1, then the value parameter will contain an invalid pointer
2) since finalisation involves a call, for optimal code generation
purposes they should also be evaluated first
(mantis #28279, #28390)
git-svn-id: trunk@31201 -
59 lines
982 B
ObjectPascal
59 lines
982 B
ObjectPascal
{$mode objfpc}
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program Project1;
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var
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value_para_must_be_empty: boolean;
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procedure Foo1(a: AnsiString; out b: AnsiString);
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begin
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WriteLn(length(a)); WriteLn(length(b));
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if value_para_must_be_empty and
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(a<>'') then
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halt(2);
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if b<>'' then
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halt(3);
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b := 'a';
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end;
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procedure Foo2(out a: AnsiString; b: AnsiString);
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begin
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WriteLn(length(a)); WriteLn(length(b));
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if a<>'' then
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halt(4);
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if value_para_must_be_empty and
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(b<>'') then
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halt(5);
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b := 'a';
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end;
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var s1: AnsiString;
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function f: ansistring;
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begin
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{ the s1 parameter must be finalised first to prevent accidental use of
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the finalised value }
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if s1<>'' then
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halt(1);
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f:='a';
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f:=f+'b';
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end;
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const x: AnsiString = 'abcde';
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begin
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value_para_must_be_empty:=true;
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s1 := copy(x,2,3)+'x';
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Foo1(s1,s1);
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s1 := copy(x,2,3)+'x';
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Foo2(s1,s1);
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value_para_must_be_empty:=false;
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s1 := copy(x,2,3)+'x';
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Foo1(f,s1);
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s1 := copy(x,2,3)+'x';
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Foo2(s1,f);
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end.
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