void block(int pIndex) /* pIndex はこのブロックの関数名のインデックス */
{
int backP;
backP = genCodeV(jmp, 0); /* 内部関数を飛び越す命令、後でバックパッチ */
while (1) { /* 宣言部のコンパイルを繰り返す */
switch (token.kind){
case Const: /* 定数宣言部のコンパイル */
token = nextToken();
constDecl(); continue;
case Var: /* 変数宣言部のコンパイル */
token = nextToken();
varDecl(); continue;
case Func: /* 関数宣言部のコンパイル */
token = nextToken();
funcDecl(); continue;
default: /* それ以外なら宣言部は終わり */
break;
}
break;
}
backPatch(backP); /* 内部関数を飛び越す命令にパッチ */
changeV(pIndex, nextCode()); /* この関数の開始番地を修正 */
genCodeV(ict, frameL()); /* このブロックの実行時の必要記憶域をとる命令 */
statement(); /* このブロックの主文 */
genCodeR(); /* リターン命令 */
blockEnd(); /* ブロックが終ったことをtableに連絡 */
}
void fncDecl_end(void) /* 関数出口処理 */
{
backPatch(fncPt->adrs, -localAdrs); /* フレームサイズ後埋(関数先頭はADBR) */
if (last_statement != Return) { /* 関数末尾にreturnがない */
if (IS_MAIN(fncPt)) gencode2(LDI, 0); /* main関数なら戻値設定 */
else if (fncPt->dtTyp != VOID_T) /* 本処理系の独自仕様 */
err_s("本処理系では非void型関数の末尾には単独のreturn文が必要です。");
}
backPatch_RET(fncPt->adrs); /* RET命令列へ飛ぶJMPの飛先番地を後埋 */
gencode3(LOD, LOCAL_F, 0); /* 戻番地をオペランドスタックへ */
gencode2(ADBR, localAdrs); /* フレームを解放 */
gencode1(RET); /* 戻り命令 */
}
void set_main(void) /* main関数処理 */
{
if (fncPt->dtTyp != INT_T || fncPt->args != 0) /* 型と引数個数の確認 */
err_s("main関数の書式が不正");
backPatch(0, fncPt->adrs); /* 0番地のCALL命令の番地を後埋 */
}
//进行规约的操作
bool LRGramar::doGuiYue(const int ruleNum)
{
switch(ruleNum)
{
case R1:
//执行进出站等相关操作
if(!doRules(A_NTERMINAL,4))
{
return false;
}
break;
case R2:
if(!doRules(B_NTERMINAL,3))
{
return false;
}
break;
case R3:
if(!doRules(C_NTERMINAL,3))
{
return false;
}
break;
case R4:
if(!doRules(C_NTERMINAL,0))
{
return false;
}
break;
case R5:
if(!doRules(D_NTERMINAL,1))
{
return false;
}
break;
case R6:
case R7:
if(!doRules(D_NTERMINAL,1))
{
return false;
}
else
{
}
break;
case R8:
if(!doRules(F_NTERMINAL,3))
{
return false;
}
else
{
//堆栈是先进先出
int argP = variableBufferPtr--;
int resultPtr = variableBufferPtr--;
emit("=",variableBuffer[argP]," ",variableBuffer[resultPtr]);
}
break;
case R9:
if(!doRules(G_NTERMINAL,2))
{
return false;
}
else
{
backPatch(trueChainHead,nextq); //回填真链头
}
break;
case R10:
if(!doRules(S_NTERMINAL,2))
{
return false;
}
else
{
backPatch(falseChain[falseChainPtr--],nextq);
}
break;
case R11:
if(!doRules(T_NTERMINAL,3))
{
return false;
}
else
{
emit("goto","","","0");
backPatch(falseChain[falseChainPtr--],nextq);
falseChain[++falseChainPtr] = nextq-1;
}
break;
case R12:
if(!doRules(S_NTERMINAL,2))
{
return false;
}
backPatch(falseChain[falseChainPtr--],nextq);
break;
case R13:
if(!doRules(W_NTERMINAL,2))
{
return false;
}
else
{
backPatch(trueChainHead,doTrue[doTruePtr--]);
backPatch(falseChain[falseChainPtr--],nextq);
}
break;
case R14:
if(!doRules(K_NTERMINAL,1))
{
return false;
}
doTrue[++doTruePtr] = nextq;//保存do后面的地址
break;
case R15:
if(!doRules(L_NTERMINAL,2))
{
return false;
}
break;
case R16:
if(!doRules(N_NTERMINAL,2))
{
return false;
}
break;
case R17:
if(!doRules(Q_NTERMINAL,3))
{
return false;
}
else
{
trueChainHead = nextq;
falseChain[++falseChainPtr]=nextq+1;
char temp[10];
int arg2 = variableBufferPtr--;
int arg1 = variableBufferPtr--;
sprintf(temp,"%s%s%s",variableBuffer[arg1],lastOp[OpPtr--],variableBuffer[arg2]);
emit("if",temp,"goto","0");
emit("goto","","","0");
}
break;
case R18:
if(!doRules(P_NTERMINAL,2))
{
return false;
}
else
{
if(strcmp(variableBuffer[variableBufferPtr],"null")!=0)
{
char *pPlace = newTemp();
emit(lastOp[OpPtr--],variableBuffer[variableBufferPtr--],variableBuffer[variableBufferPtr--],pPlace);
strcpy(variableBuffer[++variableBufferPtr],pPlace);
}
else {
variableBufferPtr--;
}
}
break;
case R19:
if(!doRules(H_NTERMINAL,3))
{
return false;
}
else
{
if(strcmp(variableBuffer[variableBufferPtr],"null")!=0)
{
char *hPlace = newTemp();
emit(lastOp[OpPtr--],variableBuffer[variableBufferPtr--],variableBuffer[variableBufferPtr--],hPlace);
strcpy(variableBuffer[++variableBufferPtr],hPlace);
}
else {
variableBufferPtr--;
}
strcpy(lastOp[++OpPtr],"+");
}
break;
case R20:
if(!doRules(H_NTERMINAL,3))
{
return false;
}
else
{
if(strcmp(variableBuffer[variableBufferPtr],"null")!=0)
{
char *hPlace = newTemp();
emit(lastOp[OpPtr--],variableBuffer[variableBufferPtr--],variableBuffer[variableBufferPtr--],hPlace);
strcpy(variableBuffer[++variableBufferPtr],hPlace);
}
else
{
variableBufferPtr--;
}
strcpy(lastOp[++OpPtr],"-");
}
break;
case R21:
if(!doRules(H_NTERMINAL,0))
{
return false;
}
else
{
strcpy(variableBuffer[++variableBufferPtr],"null");
}
break;
case R22:
if(!doRules(Z_NTERMINAL,2))
{
return false;
}
else
{
if(strcmp(variableBuffer[variableBufferPtr],"null")!=0)
{
char *zPlace = newTemp();
emit(lastOp[OpPtr--],variableBuffer[variableBufferPtr--],variableBuffer[variableBufferPtr--],zPlace);
strcpy(variableBuffer[++variableBufferPtr],zPlace);
}
else
{
variableBufferPtr--;
}
}
break;
case R23:
if(!doRules(V_NTERMINAL,3))
{
return false;
}
else
{
if(strcmp(variableBuffer[variableBufferPtr],"null")!=0)
{
char *vPlace = newTemp();
emit(lastOp[--OpPtr],variableBuffer[variableBufferPtr--],variableBuffer[variableBufferPtr--],vPlace);
strcpy(variableBuffer[++variableBufferPtr],vPlace);
}
else
{
variableBufferPtr--;
}
strcpy(lastOp[++OpPtr] ,"*");
}
break;
case R24:
if(!doRules(V_NTERMINAL,3))
{
return false;
}
else
{
if(strcmp(variableBuffer[variableBufferPtr],"null")!=0)
{
char *vPlace = newTemp();
emit(lastOp[--OpPtr],variableBuffer[variableBufferPtr--],variableBuffer[variableBufferPtr--],vPlace);
strcpy(variableBuffer[++variableBufferPtr],vPlace);
}
else
{
variableBufferPtr--;
}
strcpy(lastOp[++OpPtr] ,"/");
}
break;
case R25:
case R26:
if(!doRules(U_NTERMINAL,1))
{
return false;
}
break;
case R27:
if(!doRules(U_NTERMINAL,3))
{
return false;
}
break;
case R28:
strcpy(lastOp[++OpPtr],"<");
if(!doRules(Y_NTERMINAL,1))
{
return false;
}
break;
case R29:
if(!doRules(Y_NTERMINAL,1))
{
return false;
}
strcpy(lastOp[++OpPtr],"<=");
break;
case R30:
if(!doRules(Y_NTERMINAL,1))
{
return false;
}
strcpy(lastOp[++OpPtr],">");
break;
case R31:
if(!doRules(Y_NTERMINAL,1))
{
return false;
}
strcpy(lastOp[++OpPtr],">=");
break;
case R32:
if(!doRules(Y_NTERMINAL,1))
{
return false;
}
strcpy(lastOp[++OpPtr],"==");
break;
case R33:
if(!doRules(Y_NTERMINAL,1))
{
return false;
}
strcpy(lastOp[++OpPtr],"!=");
break;
case R34:
if(!doRules(V_NTERMINAL,0))
{
return false;
}
else
{
strcpy(variableBuffer[++variableBufferPtr],"null");
}
break;
default:
return false;
}
return true;
}
void statement(){
int l;
int m;
symTableEntry* symbol;
int tempLabels[2];
if(currentToken == identsym){
symbol = findSymbol(symTable, VAR, tokenVal.string, scope);
if(!findVar(tokenVal.string, scope, &l, &m)){
if(findConst(tokenVal.string, scope, &m))
throwError(CANNOT_ASSIGN_TO_CONST_OR_PROC);
else
throwError(UNDEC_ID);
}
readToken();
if(currentToken != becomessym)
throwError(ASSIGN_EXPEC);
readToken();
expression();
genCode(STO, l, m);
}
else if(currentToken == syawsym){
readToken();
if(currentToken != identsym)
throwError(ID_FOLLOW_SYAW);
if(!findFunc(tokenVal.string, scope, &l, &m))
throwError(UNDEC_ID);
genCode(CAL, l, m);
readToken();
}
else if(currentToken == sngaisym){ // 'beginsym'
readToken();
statement();
while(currentToken == semicolonsym){
readToken();
statement();
}
if(currentToken != fpesym &&
(currentToken != identsym && currentToken != sngaisym
&& currentToken != txosym && currentToken != tengkrrsym)) // 'endsym'
//throwError(WRONG_SYM_AFTER_STATE);
throwError(SEMICOL_OR_RBRACK_EXPEC);
else if(currentToken == identsym || currentToken == sngaisym
|| currentToken == txosym || currentToken == tengkrrsym)
throwError(SEMICOL_BW_STATE_MISS);
readToken();
}
else if(currentToken == txosym){ // 'ifsym'
tempLabels[1] = 0;
readToken();
condition();
tempLabels[0] = reserveCode(); //Conditional jump will go here
if(currentToken != tsakrrsym) // 'thensym'
throwError(TSAKRR_EXPEC);
readToken();
statement();
if(currentToken == txokefyawsym){
tempLabels[1] = reserveCode();
readToken();
}
backPatch(tempLabels[0], JPC, 0, genLabel());
if(tempLabels[1]){
statement();
backPatch(tempLabels[1], JMP, 0, genLabel());
}
}
else if(currentToken == tengkrrsym){ // 'whilesym'
readToken();
tempLabels[0] = genLabel(); //Jump back up to here at the end of the loop
condition();
tempLabels[1] = reserveCode(); //Stick the conditional jump here
if(currentToken != sisym) // 'dosym'
throwError(SI_EXPEC);
readToken();
statement();
genCode(JMP, 0, tempLabels[0]);
backPatch(tempLabels[1], JPC, 0, genLabel());
}
else if(currentToken == misym){ // Input
genCode(SIO, 0, 2);
readToken();
if(currentToken == identsym){
if(findVar(tokenVal.string, scope, &l, &m))
genCode(STO, l, m);
else if(findConst(tokenVal.string, scope, &m)
|| findFunc(tokenVal.string, scope, &l, &m))
throwError(CANNOT_STORE_IN_CONST_OR_PROC);
else
throwError(UNDEC_ID);
readToken();
}
}
else if(currentToken == wrrpasym){ // Output
readToken();
if(currentToken == identsym){
if(findVar(tokenVal.string, scope, &l, &m))
genCode(LOD, l, m);
else if(findConst(tokenVal.string, scope, &m))
genCode(LIT, 0, m);
else
throwError(UNDEC_ID);
readToken();
}
genCode(SOI, 0, 1);
}
else if(currentToken == fpesym){
return;
}
else{
if(currentToken == periodsym)
throwError(RBRACK_EXPEC_AT_END);
else
throwError(STATEMENT_EXPEC);
}
return;
}
void block(){
int jmpLoc = reserveCode();
int thisScope;
int numVars = 0;
char tempSymbol[MAX_IDENT_LENGTH + 1];
if(currentToken == constsym){
/***************************************************************/
/* const-declaration ::= [ "const" ident "=" number */
/* {"," ident "=" number} ";"] */
/***************************************************************/
do{
readToken();
if(currentToken != identsym){
throwError(ID_FOLLOW_CONST_VAR_PROC);
}else{
strcpy(tempSymbol, tokenVal.string);
}
readToken();
if(currentToken != eqsym){
if(currentToken == becomessym)
throwError(EQ_NOT_BECOMES);
else
throwError(EQ_FOLLOW_ID);
}
readToken();
if(currentToken != numbersym){
throwError(NUM_FOLLOW_EQ);
}else{
insertSymbol(symTable, newSymbol(CONST, tempSymbol, scope, 0,
tokenVal.numeric));
}
readToken();
}while(currentToken == commasym);
if(currentToken != semicolonsym)
throwError(SEMICOL_COMMA_MISS);
readToken();
}
if(currentToken == intsym){
/*******************************************************/
/* var-declaration ::= ["int" ident {"," ident} ";"] */
/*******************************************************/
do{
readToken();
if(currentToken != identsym){
throwError(ID_FOLLOW_CONST_VAR_PROC);
}else{
insertSymbol(symTable, newSymbol(VAR, tokenVal.string,
scope, BASE_OFFSET + numVars++, 0));
}
readToken();
}while(currentToken == commasym);
if(currentToken != semicolonsym)
throwError(SEMICOL_COMMA_MISS);
readToken();
}
//Saving the scope before moving into procedure declarations
thisScope = scope;
while(currentToken == procsym){
/**********************************************************************/
/* proc-declaration ::= {"procedure" ident ";" block ";"} statement */
/**********************************************************************/
readToken();
if(currentToken != identsym)
throwError(ID_FOLLOW_CONST_VAR_PROC);
//Storing the function name in the symbol table
insertSymbol(symTable, newSymbol(FUNC, tokenVal.string, thisScope,
genLabel(), 0));
readToken();
if(currentToken != semicolonsym)
throwError(SEMICOL_COMMA_MISS);
readToken();
//Incrementing the scope for our new function and saving its parent
//in the disjoint set
scope++;
scopeParent[scope] = thisScope;
block();
if(currentToken != semicolonsym)
throwError(WRONG_SYM_AFTER_PROC);
readToken();
}
//Restoring the scope
scope = thisScope;
backPatch(jmpLoc, JMP, 0, genLabel());
genCode(INC, 0, BASE_OFFSET + numVars);
statement();
genCode(OPR, 0, RET);
return;
}
void statement() /* 文のコンパイル */
{
int tIndex;
KindT k;
int backP, backP2; /* バックパッチ用 */
while(1) {
switch (token.kind) {
case Id: /* 代入文のコンパイル */
tIndex = searchT(token.u.id, varId); /* 左辺の変数のインデックス */
setIdKind(k=kindT(tIndex)); /* 印字のための情報のセット */
if (k != varId && k != parId) /* 変数名かパラメタ名のはず */
errorType("var/par");
token = checkGet(nextToken(), Assign); /* ":="のはず */
expression(); /* 式のコンパイル */
genCodeT(sto, tIndex); /* 左辺への代入命令 */
return;
case If: /* if文のコンパイル */
token = nextToken();
condition(); /* 条件式のコンパイル */
token = checkGet(token, Then); /* "then"のはず */
backP = genCodeV(jpc, 0); /* jpc命令 */
statement(); /* 文のコンパイル */
backPatch(backP); /* 上のjpc命令にバックパッチ */
return;
case Ret: /* return文のコンパイル */
token = nextToken();
expression(); /* 式のコンパイル */
genCodeR(); /* ret命令 */
return;
case Begin: /* begin . . end文のコンパイル */
token = nextToken();
while(1){
statement(); /* 文のコンパイル */
while(1){
if (token.kind==Semicolon){ /* 次が";"なら文が続く */
token = nextToken();
break;
}
if (token.kind==End){ /* 次がendなら終り */
token = nextToken();
return;
}
if (isStBeginKey(token)){ /* 次が文の先頭記号なら */
errorInsert(Semicolon); /* ";"を忘れたことにする */
break;
}
errorDelete(); /* それ以外ならエラーとして読み捨てる */
token = nextToken();
}
}
case While: /* while文のコンパイル */
token = nextToken();
backP2 = nextCode(); /* while文の最後のjmp命令の飛び先 */
condition(); /* 条件式のコンパイル */
token = checkGet(token, Do); /* "do"のはず */
backP = genCodeV(jpc, 0); /* 条件式が偽のとき飛び出すjpc命令 */
statement(); /* 文のコンパイル */
genCodeV(jmp, backP2); /* while文の先頭へのジャンプ命令 */
backPatch(backP); /* 偽のとき飛び出すjpc命令へのバックパッチ */
return;
case Write: /* write文のコンパイル */
token = nextToken();
expression(); /* 式のコンパイル */
genCodeO(wrt); /* その値を出力するwrt命令 */
return;
case WriteLn: /* writeln文のコンパイル */
token = nextToken();
genCodeO(wrl); /* 改行を出力するwrl命令 */
return;
case End: case Semicolon: /* 空文を読んだことにして終り */
return;
default: /* 文の先頭のキーまで読み捨てる */
errorDelete(); /* 今読んだトークンを読み捨てる */
token = nextToken();
continue;
}
}
}