m68k: assembler reader changes

* don't reimplement BuildStringConst, use the inherited one
* findopcode's string argument is now const, simplified the function and removed some dead code
* removed an intentional null ptr write in an error path, which was debug code and left in accidentally

git-svn-id: trunk@32829 -

compiler/m68k/ra68kmot.pas

@@ -78,7 +78,7 @@ unit ra68kmot;
          function is_register(const s:string):boolean;
          procedure GetToken;
          function consume(t : tasmtoken):boolean;
-         function findopcode(s: string; var opsize: topsize): tasmop;
+         function findopcode(const s: string; var opsize: topsize): tasmop;
          Function BuildExpression(allow_symbol : boolean; asmsym : pshortstring) : longint;
          Procedure BuildConstant(maxvalue: longint);
          Procedure BuildRealConstant(typ : tfloattype);
@@ -86,7 +86,6 @@ unit ra68kmot;
          Function BuildRefExpression: longint;
          procedure BuildReference(const oper:tm68koperand);
          Procedure BuildOperand(const oper:tm68koperand);
-         Procedure BuildStringConstant(asciiz: boolean);
          Procedure BuildOpCode(instr:Tm68kinstruction);
       end;
 
@@ -556,14 +555,10 @@ const
   {---------------------------------------------------------------------}
 
     function tm68kmotreader.consume(t : tasmtoken):boolean;
-      var
-        p: pointer;
       begin
         Consume:=true;
         if t<>actasmtoken then
          begin
-           p:=nil;
-           dword(p^):=0;
            Message2(scan_f_syn_expected,token2str[t],token2str[actasmtoken]);
            Consume:=false;
          end;
@@ -573,24 +568,21 @@ const
       end;
 
 
-   function tm68kmotreader.findopcode(s: string; var opsize: topsize): tasmop;
+   function tm68kmotreader.findopcode(const s: string; var opsize: topsize): tasmop;
   {*********************************************************************}
   { FUNCTION findopcode(s: string): tasmop;                             }
   {  Description: Determines if the s string is a valid opcode          }
   {  if so returns correct tasmop token.                                }
   {*********************************************************************}
    var
-    j: byte;
-    op_size: string;
+     j: longint;
    begin
-     findopcode := A_NONE;
      j:=pos('.',s);
-     if j<>0 then
+     if (j <> 0) and (j < length(s)) then
      begin
-       op_size:=copy(s,j+1,1);
-       case op_size[1] of
+       case s[j+1] of
        { For the motorola only opsize size is used to }
-       { determine the size of the operands.             }
+       { determine the size of the operands.          }
        'B': opsize := S_B;
        'W': opsize := S_W;
        'L': opsize := S_L;
@@ -598,10 +590,8 @@ const
        'D': opsize := S_FD;
        'X': opsize := S_FX;
        else
-        Message1(asmr_e_unknown_opcode,s);
+         Message1(asmr_e_unknown_opcode,s);
        end;
-       { delete everything starting from dot }
-       delete(s,j,length(s));
      end;
      result:=actopcode;
    end;
@@ -1655,46 +1645,6 @@ const
  end;
 
 
-
-  Procedure tm68kmotreader.BuildStringConstant(asciiz: boolean);
-  {*********************************************************************}
-  { PROCEDURE BuildStringConstant                                       }
-  {  Description: Takes care of a ASCII, or ASCIIZ directive.           }
-  {   asciiz: boolean -> if true then string will be null terminated.   }
-  {*********************************************************************}
-  { EXIT CONDITION:  On exit the routine should point to AS_SEPARATOR.  }
-  { On ENTRY: Token should point to AS_STRING                           }
-  {*********************************************************************}
-  var
-   expr: string;
-   errorflag : boolean;
-  begin
-      errorflag := FALSE;
-      Repeat
-        Case actasmtoken of
-          AS_STRING: begin
-                      expr:=actasmpattern;
-                      if asciiz then
-                       expr:=expr+#0;
-                      ConcatString(curlist,expr);
-                      Consume(AS_STRING);
-                    end;
-          AS_COMMA:  begin
-                       Consume(AS_COMMA);
-                     END;
-          AS_SEPARATOR: ;
-        else
-         begin
-          Consume(actasmtoken);
-          if not errorflag then
-           Message(asmr_e_invalid_string_expression);
-          errorflag := TRUE;
-         end;
-    end; { end case }
-   Until actasmtoken = AS_SEPARATOR;
-  end;
-
-
   Procedure TM68kmotReader.BuildOpCode(instr:Tm68kinstruction);
   {*********************************************************************}
   { PROCEDURE BuildOpcode;                                              }