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Fix emit_ansistr_const: its input is not guaranteed to be #0-terminated

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Also cleaned up all memory leaks where pchars were allocated, but never freed.
Before the change to dynamic arrays, these pchars were kept in the tai_string,
but now they got copied. Changed the tai_string constructor to support adding
a terminating #0, so we don't need to create intermediates just for that.
This commit is contained in:
Jonas Maebe 2025-03-24 22:16:24 +01:00
parent dc5c99be6d
commit 547fa426c7
7 changed files with 56 additions and 86 deletions
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46
compiler/aasmcnst.pas
View File

@ -349,7 +349,8 @@ type
class function get_dynstring_rec_name(typ: tstringtype; winlike: boolean; len: asizeint): TSymStr;
class function get_dynstring_rec(typ: tstringtype; winlike: boolean; len: asizeint): trecorddef;
{ the datalist parameter specifies where the data for the string constant
will be emitted (via an internal data builder) }
will be emitted (via an internal data builder)
Note: data does not have to be #0-terminated (len specifies the length of the valid data) }
function emit_ansistring_const(datalist: TAsmList; data: pchar; len: asizeint; encoding: tstringencoding): tasmlabofs;
function emit_unicodestring_const(datalist: TAsmList; data: tcompilerwidestring; encoding: tstringencoding; winlike: boolean):tasmlabofs;
{ emits a tasmlabofs as returned by emit_*string_const }
@ -364,8 +365,9 @@ type
{ emit a shortstring constant, and return its def }
function emit_shortstring_const(const str: shortstring): tdef;
{ emit a pchar string constant (the characters, not a pointer to them), and return its def }
function emit_pchar_const(str: pchar; len: pint; copypchar: boolean): tdef;
{ emit a pchar string constant (the characters, not a pointer to them), and return its def;
len does not include the terminating #0 (will be added) }
function emit_pchar_const(str: pchar; len: pint): tdef;
{ emit a guid constant }
procedure emit_guid_const(const guid: tguid);
{ emit a procdef constant }
@ -735,8 +737,8 @@ implementation
ait_string:
begin
// lengths without terminating 0
len1:=length(strtai.str)-1;
len2:=length(lother_string.str)-1;
len1:=strtai.len;
len2:=lother_string.len;
lent:=len1+len2;
SetLength(strtai.str,lent+1);
{ also copy null terminator }
@ -842,7 +844,7 @@ implementation
if fvalues.count<>1 then
internalerror(2014070105);
lString:=tai_string(tai_simpletypedconst(fvalues[0]).val);
len:=length(lString.str)-1;
len:=lString.len;
tai_simpletypedconst(fvalues[0]).fdef:=carraydef.getreusable(cansichartype,len);
end;
end;
@ -1704,7 +1706,6 @@ implementation
function ttai_typedconstbuilder.emit_ansistring_const(datalist: TAsmList; data: pchar; len: asizeint; encoding: tstringencoding): tasmlabofs;
var
s: PChar;
startlab: tasmlabel;
ansistrrecdef: trecorddef;
datadef: tdef;
@ -1714,10 +1715,10 @@ implementation
start_internal_data_builder(datalist,sec_rodata_norel,'',datatcb,startlab);
result:=datatcb.emit_string_const_common(st_ansistring,len,encoding,startlab);
{ terminating zero included }
{ add room for the #0-terminator }
datadef:=carraydef.getreusable(cansichartype,len+1);
datatcb.maybe_begin_aggregate(datadef);
ts:=tai_string.create_pchar(data,len+1); // +1 to include terminating 0
ts:=tai_string.Create_Data(data,len,true);
datatcb.emit_tai(ts,datadef);
datatcb.maybe_end_aggregate(datadef);
ansistrrecdef:=datatcb.end_anonymous_record;
@ -1850,26 +1851,14 @@ implementation
end;
function ttai_typedconstbuilder.emit_pchar_const(str: pchar; len: pint; copypchar: boolean): tdef;
var
newstr: pchar;
function ttai_typedconstbuilder.emit_pchar_const(str: pchar; len: pint): tdef;
begin
result:=carraydef.getreusable(cansichartype,len+1);
maybe_begin_aggregate(result);
if (len=0) and
(not assigned(str) or
copypchar) then
if len=0 then
emit_tai(Tai_const.Create_8bit(0),cansichartype)
else
begin
if copypchar then
begin
getmem(newstr,len+1);
move(str^,newstr^,len+1);
str:=newstr;
end;
emit_tai(Tai_string.Create_pchar(str,len+1),result);
end;
emit_tai(Tai_string.Create_Data(str,len,true),result);
maybe_end_aggregate(result);
end;
@ -1926,7 +1915,6 @@ implementation
entry : phashsetitem;
strlab : tasmlabel;
l : longint;
pc : pansichar;
datadef : tdef;
strtcb : ttai_typedconstbuilder;
begin
@ -1941,11 +1929,6 @@ implementation
{ include length and terminating zero for quick conversion to pchar }
l:=length(str);
getmem(pc,l+2);
move(str[1],pc[1],l);
pc[0]:=chr(l);
pc[l+1]:=#0;
datadef:=carraydef.getreusable(cansichartype,l+2);
{ we start a new constbuilder as we don't know whether we're called
@ -1953,7 +1936,8 @@ implementation
strtcb:=ctai_typedconstbuilder.create([tcalo_is_lab,tcalo_make_dead_strippable,tcalo_apply_constalign]);
strtcb.maybe_begin_aggregate(datadef);
strtcb.emit_tai(Tai_string.Create_pchar(pc,l+2),datadef);
{ l+1: include length byte; true: add terminating #0 }
strtcb.emit_tai(Tai_string.Create_Data(@str[0],l+1,true),datadef);
strtcb.maybe_end_aggregate(datadef);
current_asmdata.asmlists[al_typedconsts].concatList(

19
compiler/aasmtai.pas
View File

@ -611,7 +611,11 @@ interface
str : TAnsiCharDynArray;
constructor Create(const _str : string);
constructor Create(const _str : ansistring);
constructor Create_pchar(_str : pchar;length : longint);
{ data: not guaranteed to #0-terminated
length: length of the data without #0 terminator (unless the #0
terminator itself must be included)
add0: add a terminating zero as part of the data after data }
constructor Create_Data(data : pchar;length : longint; add0: boolean);
destructor Destroy;override;
constructor ppuload(t:taitype;ppufile:tcompilerppufile);override;
procedure ppuwrite(ppufile:tcompilerppufile);override;
@ -2445,14 +2449,19 @@ implementation
end;
constructor tai_string.Create_pchar(_str : pchar;length : longint);
constructor tai_string.Create_Data(data : pchar;length : longint; add0: boolean);
begin
inherited Create;
typ:=ait_string;
setlength(str,length+1);
str[length]:=#0;
setlength(str,length+ord(add0)+1);
if length>0 then
move(_str^,str[0],length);
move(data^,str[0],length);
if add0 then
begin
str[length]:=#0;
inc(length);
end;
str[length]:=#0;
end;

4
compiler/ncal.pas
View File

@ -592,11 +592,11 @@ implementation
if variantdispatch then
begin
tcb.emit_pchar_const(pchar(methodname),length(methodname),true);
tcb.emit_pchar_const(pchar(methodname),length(methodname));
if names<>'' then
{ length-1 because we added a null terminator to the string itself
already }
tcb.emit_pchar_const(pchar(names),length(names)-1,true);
tcb.emit_pchar_const(pchar(names),length(names)-1);
end;
{ may be referred from other units in case of inlining -> global

18
compiler/ncgcon.pas
View File

@ -220,7 +220,6 @@ implementation
procedure tcgstringconstnode.pass_generate_code;
var
lastlabel: tasmlabofs;
pc: pchar;
l: longint;
pool: THashSet;
entry: PHashSetItem;
@ -332,15 +331,12 @@ implementation
l:=255
else
l:=len;
{ include length and terminating zero for quick conversion to pchar }
getmem(pc,l+2);
if l>0 then
move(asconstpchar^,pc[1],l);
pc[0]:=chr(l);
pc[l+1]:=#0;
datadef:=carraydef.getreusable(cansichartype,l+2);
datatcb.maybe_begin_aggregate(datadef);
t:=Tai_string.Create_pchar(pc,l+2);
datatcb.emit_tai(Tai_const.Create_8bit(l),cansichartype);
t:=Tai_string.Create_Data(asconstpchar,l,true);
datatcb.emit_tai(t,datadef);
datatcb.maybe_end_aggregate(datadef);
current_asmdata.asmlists[al_typedconsts].concatList(
@ -351,20 +347,14 @@ implementation
begin
current_asmdata.getlocaldatalabel(lastlabel.lab);
{ include terminating zero }
getmem(pc,len+1);
if len>0 then
move(asconstpchar^,pc[0],len);
pc[len]:=#0;
{ the data includes the terminating #0 because this
string can be used for pchar assignments (but it's
also used for array-of-char assignments, in which
case the terminating #0 is not part of the data) }
datadef:=carraydef.getreusable(cansichartype,len+1);
datatcb.maybe_begin_aggregate(datadef);
t:=Tai_string.Create_pchar(pc,len+1);
t:=Tai_string.Create_Data(asconstpchar,len,true);
datatcb.emit_tai(t,datadef);
freemem(pc);
datatcb.maybe_end_aggregate(datadef);
current_asmdata.asmlists[al_typedconsts].concatList(
datatcb.get_final_asmlist(lastlabel.lab,datadef,sec_rodata_norel,lastlabel.lab.name,const_align(sizeof(pint)))

9
compiler/ncgvmt.pas
View File

@ -227,20 +227,15 @@ implementation
procedure TVMTWriter.writenames(tcb: ttai_typedconstbuilder; p: pprocdeftree);
var
ca : pchar;
len : byte;
datatcb : ttai_typedconstbuilder;
len : byte;
begin
if assigned(p^.l) then
writenames(tcb,p^.l);
tcb.start_internal_data_builder(current_asmdata.AsmLists[al_const],sec_rodata,_class.vmt_mangledname,datatcb,p^.nl);
len:=length(p^.data.messageinf.str^);
datatcb.maybe_begin_aggregate(carraydef.getreusable(cansichartype,len+1));
datatcb.emit_tai(tai_const.create_8bit(len),cansichartype);
getmem(ca,len+1);
move(p^.data.messageinf.str^[1],ca^,len);
ca[len]:=#0;
datatcb.emit_tai(Tai_string.Create_pchar(ca,len),carraydef.getreusable(cansichartype,len));
datatcb.emit_tai(Tai_string.Create_Data(@p^.data.messageinf.str^[0],len+1,false),carraydef.getreusable(cansichartype,len+1));
datatcb.maybe_end_aggregate(carraydef.getreusable(cansichartype,len+1));
tcb.finish_internal_data_builder(datatcb,p^.nl,carraydef.getreusable(cansichartype,len+1),sizeof(pint));
if assigned(p^.r) then

39
compiler/ngtcon.pas
View File

@ -486,12 +486,13 @@ function get_next_varsym(def: tabstractrecorddef; const SymList:TFPHashObjectLis
procedure tasmlisttypedconstbuilder.tc_emit_stringdef(def: tstringdef; var node: tnode);
var
strlength : {$ifdef CPU8BITALU}smallint{$else}aint{$endif};
strlength,
defsize : {$ifdef CPU8BITALU}smallint{$else}aint{$endif};
strval : pchar;
ll : tasmlabofs;
ca : pchar;
winlike : boolean;
hsym : tconstsym;
paddedstrdata : shortstring;
begin
strval:='';
{ load strval and strlength of the constant tree }
@ -562,20 +563,18 @@ function get_next_varsym(def: tabstractrecorddef; const SymList:TFPHashObjectLis
st_shortstring:
begin
ftcb.maybe_begin_aggregate(def);
if strlength>=def.size then
defsize:=def.size;
if strlength>=defsize then
begin
message2(parser_w_string_too_long,strpas(strval),tostr(def.size-1));
strlength:=def.size-1;
message2(parser_w_string_too_long,strval,tostr(defsize-1));
strlength:=defsize-1;
end;
ftcb.emit_tai(Tai_const.Create_8bit(strlength),cansichartype);
{ room for the string data + terminating #0 }
getmem(ca,def.size);
move(strval^,ca^,strlength);
{ zero-terminate and fill with spaces if size is shorter }
fillchar(ca[strlength],def.size-strlength-1,' ');
ca[strlength]:=#0;
ca[def.size-1]:=#0;
ftcb.emit_tai(Tai_string.Create_pchar(ca,def.size-1),carraydef.getreusable(cansichartype,def.size-1));
paddedstrdata[0]:=chr(strlength);
move(strval^,paddedstrdata[1],strlength);
{ fill with spaces if size is shorter }
fillchar(paddedstrdata[strlength+1],defsize-strlength-1,' ');
paddedstrdata[strlength+1]:=#0;
ftcb.emit_tai(Tai_string.Create_Data(@paddedstrdata[0],defsize,false),carraydef.getreusable(cansichartype,defsize+1));
ftcb.maybe_end_aggregate(def);
end;
st_ansistring:
@ -783,7 +782,6 @@ function get_next_varsym(def: tabstractrecorddef; const SymList:TFPHashObjectLis
hp : tnode;
srsym : tsym;
pd : tprocdef;
ca : pchar;
pw : tcompilerwidestring;
i,len : longint;
ll : tasmlabel;
@ -876,14 +874,13 @@ function get_next_varsym(def: tabstractrecorddef; const SymList:TFPHashObjectLis
{ For tp7 the maximum lentgh can be 255 }
if (m_tp7 in current_settings.modeswitches) and
(len>255) then
len:=255;
getmem(ca,len+1);
ca[len]:=#0;
if len>0 then
move(tstringconstnode(node).valueas[0],ca^,len);
len:=255;
datadef:=carraydef.getreusable(cansichartype,len+1);
datatcb.maybe_begin_aggregate(datadef);
datatcb.emit_tai(Tai_string.Create_pchar(ca,len+1),datadef);
if len>0 then
datatcb.emit_tai(Tai_string.Create_Data(@tstringconstnode(node).valueas[0],len,true),datadef)
else
datatcb.emit_tai(Tai_string.Create_Data(nil,0,true),datadef);
datatcb.maybe_end_aggregate(datadef);
end
else if is_constcharnode(node) then

7
compiler/objcgutl.pas
View File

@ -151,7 +151,6 @@ procedure objcreatestringpoolentryintern(p: pchar; len: longint; pooltype: tcons
var
entry : PHashSetItem;
strlab : tasmlabel;
pc : pchar;
pool : THashSet;
tcb : ttai_typedconstbuilder;
begin
@ -167,13 +166,9 @@ procedure objcreatestringpoolentryintern(p: pchar; len: longint; pooltype: tcons
{ Make sure strlab has a reference }
strlab.increfs;
getmem(pc,entry^.keylength+1);
move(entry^.key^,pc^,entry^.keylength);
pc[entry^.keylength]:=#0;
{ add the string to the approriate section }
tcb:=ctai_typedconstbuilder.create([tcalo_is_lab,tcalo_new_section]);
def:=tcb.emit_pchar_const(pc,entry^.keylength,false);
def:=tcb.emit_pchar_const(pchar(entry^.key),entry^.keylength);
current_asmdata.asmlists[al_objc_pools].concatList(
tcb.get_final_asmlist(strlab,def,stringsec,strlab.name,1)
);