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* fixed tw4554:

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* proper uninitialized checking for arrays
    * first check uninitialized status of right side of assignment
      before setting the left side to "written" (-> catch "x:=x" if
      x is uninitialized)

git-svn-id: trunk@2038 -
This commit is contained in:
Jonas Maebe 2005-12-23 21:08:48 +00:00
parent 84aab46550
commit 857664a5d4
3 changed files with 21 additions and 10 deletions
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7
compiler/htypechk.pas
View File

@ -773,8 +773,11 @@ implementation
vecn:
begin
set_varstate(tbinarynode(p).right,vs_read,[vsf_must_be_valid]);
if not(tunarynode(p).left.resulttype.def.deftype in [stringdef,arraydef]) then
include(varstateflags,vsf_must_be_valid);
if (newstate in [vs_read,vs_readwritten]) or
not(tunarynode(p).left.resulttype.def.deftype in [stringdef,arraydef]) then
include(varstateflags,vsf_must_be_valid)
else if (newstate = vs_written) then
exclude(varstateflags,vsf_must_be_valid);
p:=tunarynode(p).left;
end;
{ do not parse calln }

2
compiler/nld.pas
View File

@ -564,8 +564,8 @@ implementation
end;
resulttypepass(right);
set_varstate(left,vs_written,[]);
set_varstate(right,vs_read,[vsf_must_be_valid]);
set_varstate(left,vs_written,[]);
if codegenerror then
exit;

22
compiler/nmem.pas
View File

@ -443,9 +443,12 @@ implementation
{ this is like the function addr }
inc(parsing_para_level);
{ this is actually only "read", but treat it nevertheless as modified }
{ due to the possible use of pointers }
set_varstate(left,vs_readwritten,[]);
{ This is actually only "read", but treat it nevertheless as }
{ modified due to the possible use of pointers }
{ To avoid false positives regarding "uninitialised" }
{ warnings when using arrays, perform it in two steps }
set_varstate(left,vs_written,[]);
set_varstate(left,vs_read,[]);
dec(parsing_para_level);
end;
@ -660,11 +663,16 @@ implementation
ansi/widestring needs to be valid }
valid:=is_dynamic_array(left.resulttype.def) or
is_ansistring(left.resulttype.def) or
is_widestring(left.resulttype.def);
is_widestring(left.resulttype.def) or
{ implicit pointer dereference -> pointer is read }
(left.resulttype.def.deftype = pointerdef);
if valid then
set_varstate(left,vs_read,[vsf_must_be_valid])
else
set_varstate(left,vs_read,[]);
set_varstate(left,vs_read,[vsf_must_be_valid]);
{
A vecn is, just like a loadn, always part of an expression with its
own read/write and must_be_valid semantics. Therefore we don't have
to do anything else here, just like for loadn's
}
set_varstate(right,vs_read,[vsf_must_be_valid]);
if codegenerror then
exit;