tclcompcmds.c

来自「tcl是工具命令语言」· C语言 代码 · 共 2,168 行 · 第 1/5 页

	    CONST char *varName = varvList[loopIndex][j];
	    int nameChars = strlen(varName);
	    varListPtr->varIndexes[j] = TclFindCompiledLocal(varName,
		    nameChars, /*create*/ 1, /*flags*/ VAR_SCALAR, procPtr);
	}
	infoPtr->varLists[loopIndex] = varListPtr;
    }
    infoIndex = TclCreateAuxData((ClientData) infoPtr, &tclForeachInfoType, envPtr);

    /*
     * Evaluate then store each value list in the associated temporary.
     */

    range = TclCreateExceptRange(LOOP_EXCEPTION_RANGE, envPtr);
    
    loopIndex = 0;
    for (i = 0, tokenPtr = parsePtr->tokenPtr;
	    i < numWords-1;
	    i++, tokenPtr += (tokenPtr->numComponents + 1)) {
	if ((i%2 == 0) && (i > 0)) {
	    code = TclCompileTokens(interp, tokenPtr+1,
		    tokenPtr->numComponents, envPtr);
	    if (code != TCL_OK) {
		goto done;
	    }

	    tempVar = (firstValueTemp + loopIndex);
	    if (tempVar <= 255) {
		TclEmitInstInt1(INST_STORE_SCALAR1, tempVar, envPtr);
	    } else {
		TclEmitInstInt4(INST_STORE_SCALAR4, tempVar, envPtr);
	    }
	    TclEmitOpcode(INST_POP, envPtr);
	    loopIndex++;
	}
    }

    /*
     * Initialize the temporary var that holds the count of loop iterations.
     */

    TclEmitInstInt4(INST_FOREACH_START4, infoIndex, envPtr);
    
    /*
     * Top of loop code: assign each loop variable and check whether
     * to terminate the loop.
     */

    envPtr->exceptArrayPtr[range].continueOffset =
	    (envPtr->codeNext - envPtr->codeStart);
    TclEmitInstInt4(INST_FOREACH_STEP4, infoIndex, envPtr);
    TclEmitForwardJump(envPtr, TCL_FALSE_JUMP, &jumpFalseFixup);
    
    /*
     * Inline compile the loop body.
     */

    envPtr->exceptArrayPtr[range].codeOffset =
	    (envPtr->codeNext - envPtr->codeStart);
    code = TclCompileCmdWord(interp, bodyTokenPtr+1,
	    bodyTokenPtr->numComponents, envPtr);
    envPtr->currStackDepth = savedStackDepth + 1;
    if (code != TCL_OK) {
	if (code == TCL_ERROR) {
	    sprintf(buffer, "\n    (\"foreach\" body line %d)",
		    interp->errorLine);
            Tcl_AddObjErrorInfo(interp, buffer, -1);
        }
	goto done;
    }
    envPtr->exceptArrayPtr[range].numCodeBytes =
	    (envPtr->codeNext - envPtr->codeStart)
	    - envPtr->exceptArrayPtr[range].codeOffset;
    TclEmitOpcode(INST_POP, envPtr);
	
    /*
     * Jump back to the test at the top of the loop. Generate a 4 byte jump
     * if the distance to the test is > 120 bytes. This is conservative and
     * ensures that we won't have to replace this jump if we later need to
     * replace the ifFalse jump with a 4 byte jump.
     */

    jumpBackOffset = (envPtr->codeNext - envPtr->codeStart);
    jumpBackDist =
	(jumpBackOffset - envPtr->exceptArrayPtr[range].continueOffset);
    if (jumpBackDist > 120) {
	TclEmitInstInt4(INST_JUMP4, -jumpBackDist, envPtr);
    } else {
	TclEmitInstInt1(INST_JUMP1, -jumpBackDist, envPtr);
    }

    /*
     * Fix the target of the jump after the foreach_step test.
     */

    jumpDist = (envPtr->codeNext - envPtr->codeStart)
	    - jumpFalseFixup.codeOffset;
    if (TclFixupForwardJump(envPtr, &jumpFalseFixup, jumpDist, 127)) {
	/*
	 * Update the loop body's starting PC offset since it moved down.
	 */

	envPtr->exceptArrayPtr[range].codeOffset += 3;

	/*
	 * Update the jump back to the test at the top of the loop since it
	 * also moved down 3 bytes.
	 */

	jumpBackOffset += 3;
	jumpPc = (envPtr->codeStart + jumpBackOffset);
	jumpBackDist += 3;
	if (jumpBackDist > 120) {
	    TclUpdateInstInt4AtPc(INST_JUMP4, -jumpBackDist, jumpPc);
	} else {
	    TclUpdateInstInt1AtPc(INST_JUMP1, -jumpBackDist, jumpPc);
	}
    }

    /*
     * Set the loop's break target.
     */

    envPtr->exceptArrayPtr[range].breakOffset =
	    (envPtr->codeNext - envPtr->codeStart);
    
    /*
     * The foreach command's result is an empty string.
     */

    envPtr->currStackDepth = savedStackDepth;
    TclEmitPush(TclRegisterNewLiteral(envPtr, "", 0), envPtr);
    envPtr->currStackDepth = savedStackDepth + 1;

    done:
    for (loopIndex = 0;  loopIndex < numLists;  loopIndex++) {
	if (varvList[loopIndex] != (CONST char **) NULL) {
	    ckfree((char *) varvList[loopIndex]);
	}
    }
    if (varcList != varcListStaticSpace) {
	ckfree((char *) varcList);
        ckfree((char *) varvList);
    }
    envPtr->exceptDepth--;
    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * DupForeachInfo --
 *
 *	This procedure duplicates a ForeachInfo structure created as
 *	auxiliary data during the compilation of a foreach command.
 *
 * Results:
 *	A pointer to a newly allocated copy of the existing ForeachInfo
 *	structure is returned.
 *
 * Side effects:
 *	Storage for the copied ForeachInfo record is allocated. If the
 *	original ForeachInfo structure pointed to any ForeachVarList
 *	records, these structures are also copied and pointers to them
 *	are stored in the new ForeachInfo record.
 *
 *----------------------------------------------------------------------
 */

static ClientData
DupForeachInfo(clientData)
    ClientData clientData;	/* The foreach command's compilation
				 * auxiliary data to duplicate. */
{
    register ForeachInfo *srcPtr = (ForeachInfo *) clientData;
    ForeachInfo *dupPtr;
    register ForeachVarList *srcListPtr, *dupListPtr;
    int numLists = srcPtr->numLists;
    int numVars, i, j;
    
    dupPtr = (ForeachInfo *) ckalloc((unsigned)
	    (sizeof(ForeachInfo) + (numLists * sizeof(ForeachVarList *))));
    dupPtr->numLists = numLists;
    dupPtr->firstValueTemp = srcPtr->firstValueTemp;
    dupPtr->loopCtTemp = srcPtr->loopCtTemp;
    
    for (i = 0;  i < numLists;  i++) {
	srcListPtr = srcPtr->varLists[i];
	numVars = srcListPtr->numVars;
	dupListPtr = (ForeachVarList *) ckalloc((unsigned)
	        sizeof(ForeachVarList) + numVars*sizeof(int));
	dupListPtr->numVars = numVars;
	for (j = 0;  j < numVars;  j++) {
	    dupListPtr->varIndexes[j] =	srcListPtr->varIndexes[j];
	}
	dupPtr->varLists[i] = dupListPtr;
    }
    return (ClientData) dupPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * FreeForeachInfo --
 *
 *	Procedure to free a ForeachInfo structure created as auxiliary data
 *	during the compilation of a foreach command.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Storage for the ForeachInfo structure pointed to by the ClientData
 *	argument is freed as is any ForeachVarList record pointed to by the
 *	ForeachInfo structure.
 *
 *----------------------------------------------------------------------
 */

static void
FreeForeachInfo(clientData)
    ClientData clientData;	/* The foreach command's compilation
				 * auxiliary data to free. */
{
    register ForeachInfo *infoPtr = (ForeachInfo *) clientData;
    register ForeachVarList *listPtr;
    int numLists = infoPtr->numLists;
    register int i;

    for (i = 0;  i < numLists;  i++) {
	listPtr = infoPtr->varLists[i];
	ckfree((char *) listPtr);
    }
    ckfree((char *) infoPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TclCompileIfCmd --
 *
 *	Procedure called to compile the "if" command.
 *
 * Results:
 *	The return value is a standard Tcl result, which is TCL_OK if
 *	compilation was successful. If an error occurs then the
 *	interpreter's result contains a standard error message and TCL_ERROR
 *	is returned. If the command is too complex for TclCompileIfCmd,
 *	TCL_OUT_LINE_COMPILE is returned indicating that the if command
 *	should be compiled "out of line" by emitting code to invoke its
 *	command procedure at runtime.
 *
 * Side effects:
 *	Instructions are added to envPtr to execute the "if" command
 *	at runtime.
 *
 *----------------------------------------------------------------------
 */
int
TclCompileIfCmd(interp, parsePtr, envPtr)
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tcl_Parse *parsePtr;	/* Points to a parse structure for the
				 * command created by Tcl_ParseCommand. */
    CompileEnv *envPtr;		/* Holds resulting instructions. */
{
    JumpFixupArray jumpFalseFixupArray;
    				/* Used to fix the ifFalse jump after each
				 * test when its target PC is determined. */
    JumpFixupArray jumpEndFixupArray;
				/* Used to fix the jump after each "then"
				 * body to the end of the "if" when that PC
				 * is determined. */
    Tcl_Token *tokenPtr, *testTokenPtr;
    int jumpDist, jumpFalseDist;
    int jumpIndex = 0;          /* avoid compiler warning. */
    int numWords, wordIdx, numBytes, j, code;
    CONST char *word;
    char buffer[100];
    int savedStackDepth = envPtr->currStackDepth;
                                /* Saved stack depth at the start of the first
				 * test; the envPtr current depth is restored
				 * to this value at the start of each test. */
    int realCond = 1;           /* set to 0 for static conditions: "if 0 {..}" */
    int boolVal;                /* value of static condition */
    int compileScripts = 1;            

    /*
     * Only compile the "if" command if all arguments are simple
     * words, in order to insure correct substitution [Bug 219166]
     */

    tokenPtr = parsePtr->tokenPtr;
    wordIdx = 0;
    numWords = parsePtr->numWords;

    for (wordIdx = 0; wordIdx < numWords; wordIdx++) {
	if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
	    return TCL_OUT_LINE_COMPILE;
	}
	tokenPtr += 2;
    }


    TclInitJumpFixupArray(&jumpFalseFixupArray);
    TclInitJumpFixupArray(&jumpEndFixupArray);
    code = TCL_OK;

    /*
     * Each iteration of this loop compiles one "if expr ?then? body"
     * or "elseif expr ?then? body" clause. 
     */

    tokenPtr = parsePtr->tokenPtr;
    wordIdx = 0;
    while (wordIdx < numWords) {
	/*
	 * Stop looping if the token isn't "if" or "elseif".
	 */

	word = tokenPtr[1].start;
	numBytes = tokenPtr[1].size;
	if ((tokenPtr == parsePtr->tokenPtr)
	        || ((numBytes == 6) && (strncmp(word, "elseif", 6) == 0))) {
	    tokenPtr += (tokenPtr->numComponents + 1);
	    wordIdx++;
	} else {
	    break;
	}
	if (wordIdx >= numWords) {
	    sprintf(buffer,
	            "wrong # args: no expression after \"%.30s\" argument",
		    word);
	    Tcl_ResetResult(interp);
	    Tcl_AppendToObj(Tcl_GetObjResult(interp), buffer, -1);
	    code = TCL_ERROR;
	    goto done;
	}

	/*
	 * Compile the test expression then emit the conditional jump
	 * around the "then" part. 
	 */
	
	envPtr->currStackDepth = savedStackDepth;
	testTokenPtr = tokenPtr;


	if (realCond) {
	    /*
	     * Find out if the condition is a constant. 
	     */
	
	    Tcl_Obj *boolObj = Tcl_NewStringObj(testTokenPtr[1].start,
		    testTokenPtr[1].size);
	    Tcl_IncrRefCount(boolObj);
	    code = Tcl_GetBooleanFromObj(NULL, boolObj, &boolVal);
	    Tcl_DecrRefCount(boolObj);
	    if (code == TCL_OK) {
		/*
		 * A static condition
		 */
		realCond = 0;
		if (!boolVal) {
		    compileScripts = 0;
		}
	    } else {
		Tcl_ResetResult(interp);
		code = TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
		if (code != TCL_OK) {
		    if (code == TCL_ERROR) {
			Tcl_AddObjErrorInfo(interp,
			        "\n    (\"if\" test expression)", -1);
		    }
		    goto done;
		}
		if (jumpFalseFixupArray.next >= jumpFalseFixupArray.end) {
		    TclExpandJumpFixupArray(&jumpFalseFixupArray);
		}
		jumpIndex = jumpFalseFixupArray.next;
		jumpFalseFixupArray.next++;
		TclEmitForwardJump(envPtr, TCL_FALSE_JUMP,
			       &(jumpFalseFixupArray.fixup[jumpIndex]));	    
	    }
	}


	/*
	 * Skip over the optional "then" before the then clause.
	 */

	tokenPtr = testTokenPtr + (testTokenPtr->numComponents + 1);
	wordIdx++;
	if (wordIdx >= numWords) {
	    sprintf(buffer, "wrong # args: no script following \"%.20s\" argument", testTokenPtr->start);
	    Tcl_ResetResult(interp);
	    Tcl_AppendToObj(Tcl_GetObjResult(interp), buffer, -1);
	    code = TCL_ERROR;
	    goto done;
	}
	if (tokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
	    word = tokenPtr[1].start;
	    numBytes = tokenPtr[1].size;
	    if ((numBytes == 4) && (strncmp(word, "then", 4) == 0)) {
		tokenPtr += (tokenPtr->numComponents + 1);
		wordIdx++;
		if (wordIdx >= numWords) {
		    Tcl_ResetResult(interp);
		    Tcl_AppendToObj(Tcl_GetObjResult(interp),
		            "wrong # args: no script following \"then\" argument", -1);
		    code = TCL_ERROR;
		    goto done;
		}
	    }
	}

	/*
	 * Compile the "then" command body.
	 */

	if (compileScripts) {
	    envPtr->currStackDepth = savedStackDepth;
	    code = TclCompileCmdWord(interp, tokenPtr+1,
	            tokenPtr->numComponents, envPtr);
	    if (code != TCL_OK) {
		if (code == TCL_ERROR) {
		    sprintf(buffer, "\n    (\"if\" then script line %d)",
		            interp->errorLine);
		    Tcl_AddObjErrorInfo(interp, buffer, -1);
		}
		goto done;
	    }	
	}

	if (realCond) {