Kaynağa Gözat

* Fixed checks for exceeding limit of locals space. Prevent range and overflow errors during the checks. Introduced the MaxLocalsSize constant which provides the maximum possible size of locals space (stack frame) depending of bitness of a cpu.

git-svn-id: trunk@39916 -
yury 6 yıl önce
ebeveyn
işleme
d0b6f427d3
2 değiştirilmiş dosya ile 23 ekleme ve 9 silme
  1. 8 0
      compiler/globtype.pas
  2. 15 9
      compiler/tgobj.pas

+ 8 - 0
compiler/globtype.pas

@@ -87,6 +87,14 @@ interface
        AIntBits = 8;
 {$endif cpu8bitalu}
 
+     { Maximum possible size of locals space (stack frame) }
+     Const
+{$if defined(cpu8bitalu) or defined(cpu16bitalu)}
+       MaxLocalsSize = High(AWord);
+{$else}
+       MaxLocalsSize = High(longint) - 15;
+{$endif}
+
      Type
        PAWord = ^AWord;
        PAInt = ^AInt;

+ 15 - 9
compiler/tgobj.pas

@@ -274,6 +274,11 @@ implementation
          freetype:=Used2Free[temptype];
          if freetype=tt_none then
            internalerror(200208201);
+         if size>MaxLocalsSize then
+            begin
+              CGMessage(cg_e_localsize_too_big);
+              size:=0;  // Prevent further range check errors
+            end;
          size:=align(size,alignment);
          { First check the tmpfreelist, but not when
            we don't want to reuse an already allocated block }
@@ -417,29 +422,30 @@ implementation
             tl^.temptype:=temptype;
             tl^.def:=def;
 
-{$push}
-{$r-}
-{$warn 6018 off}
-{$warn 4044 off}
             { Extend the temp }
             if direction=-1 then
               begin
-                if qword(align(-lasttemp-alignmismatch,alignment))+size+alignmismatch>high(tl^.pos) then
-                  CGMessage(cg_e_localsize_too_big);
+                if qword(align(-lasttemp-alignmismatch,alignment))+size+alignmismatch>MaxLocalsSize then
+                  begin
+                    CGMessage(cg_e_localsize_too_big);
+                    size:=0;  // Prevent further range check errors
+                  end;
                 lasttemp:=(-align(-lasttemp-alignmismatch,alignment))-size-alignmismatch;
                 tl^.pos:=lasttemp;
               end
             else
               begin
                 tl^.pos:=align(lasttemp+alignmismatch,alignment)-alignmismatch;
-                if qword(tl^.pos)+size>high(tl^.pos) then
-                  CGMessage(cg_e_localsize_too_big);
+                if qword(tl^.pos)+size>MaxLocalsSize then
+                  begin
+                    CGMessage(cg_e_localsize_too_big);
+                    size:=0;  // Prevent further range check errors
+                  end;
                 lasttemp:=tl^.pos+size;
               end;
 {$ifdef EXTDEBUG}
          Comment(V_Note,'tgobj: (AllocTemp) lasttemp set to '+tostr(lasttemp));
 {$endif}
-{$pop}
             tl^.fini:=fini;
             tl^.alignment:=alignment;
             tl^.size:=size;