/*
* tclCompExpr.c --
*
* This file contains the code to parse and compile Tcl expressions
* and implementations of the Tcl commands corresponding to expression
* operators, such as the command ::tcl::mathop::+ .
*
* Copyright (c) 1997 Sun Microsystems, Inc.
* Copyright (c) 1998-2000 by Scriptics Corporation.
* Contributions from Don Porter, NIST, 2006. (not subject to US copyright)
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* RCS: @(#) $Id: tclCompExpr.c,v 1.14.2.29 2007/07/20 04:47:52 dgp Exp $
*/
#include "tclInt.h"
#include "tclCompile.h" /* CompileEnv */
/*
* Expression parsing takes place in the routine ParseExpr(). It takes a
* string as input, parses that string, and generates a representation of
* the expression in the form of a tree of operators, a list of literals,
* a list of function names, and an array of Tcl_Token's within a Tcl_Parse
* struct. The tree is composed of OpNodes.
*/
typedef struct OpNode {
int left; /* "Pointer" to the left operand. */
int right; /* "Pointer" to the right operand. */
union {
int parent; /* "Pointer" to the parent operand. */
int prev; /* "Pointer" joining incomplete tree stack */
} p;
unsigned char lexeme; /* Code that identifies the operator. */
unsigned char precedence; /* Precedence of the operator */
} OpNode;
/*
* The storage for the tree is dynamically allocated array of OpNodes. The
* array is grown as parsing needs dictate according to a scheme similar to
* Tcl's string growth algorithm, so that the resizing costs are O(N) and so
* that we use at least half the memory allocated as expressions get large.
*
* Each OpNode in the tree represents an operator in the expression, either
* unary or binary. When parsing is completed successfully, a binary operator
* OpNode will have its left and right fields filled with "pointers" to its
* left and right operands. A unary operator OpNode will have its right field
* filled with a pointer to its single operand. When an operand is a
* subexpression the "pointer" takes the form of the index -- a non-negative
* integer -- into the OpNode storage array where the root of that
* subexpression parse tree is found.
*
* Non-operator elements of the expression do not get stored in the OpNode
* tree. They are stored in the other structures according to their type.
* Literal values get appended to the literal list. Elements that denote
* forms of quoting or substitution known to the Tcl parser get stored as
* Tcl_Tokens. These non-operator elements of the expression are the
* leaves of the completed parse tree. When an operand of an OpNode is
* one of these leaf elements, the following negative integer codes are used
* to indicate which kind of elements it is.
*/
enum OperandTypes {
OT_NONE = -4, /* Operand not yet (or no longer) known */
OT_LITERAL = -3, /* Operand is a literal in the literal list */
OT_TOKENS = -2, /* Operand is sequence of Tcl_Tokens */
OT_EMPTY = -1 /* "Operand" is an empty string. This is a
* special case used only to represent the
* EMPTY lexeme. See below. */
};
/*
* Readable macros to test whether a "pointer" value points to an operator.
* They operate on the "non-negative integer -> operator; negative integer ->
* a non-operator OperandType" distinction.
*/
#define IsOperator(l) ((l) >= 0)
#define NotOperator(l) ((l) < 0)
/*
* Note that it is sufficient to store in the tree just the type of leaf
* operand, without any explicit pointer to which leaf. This is true because
* the inorder traversals of the completed tree we perform are known to visit
* the leaves in the same order as the original parse.
*
* In a completed parse tree, those OpNodes that are themselves (roots of
* subexpression trees that are) operands of some operator store in their
* p.parent field a "pointer" to the OpNode of that operator. The p.parent
* field permits a destructive inorder traversal of the tree within a
* non-recursive routine (ConvertTreeToTokens() and CompileExprTree()). This
* means that even expression trees of great depth pose no risk of blowing
* the C stack.
*
* While the parse tree is being constructed, the same memory space is used
* to hold the p.prev field which chains together a stack of incomplete
* trees awaiting their right operands.
*
* The lexeme field is filled in with the lexeme of the operator that is
* returned by the ParseLexeme() routine. Only lexemes for unary and
* binary operators get stored in an OpNode. Other lexmes get different
* treatement.
*
* Each lexeme belongs to one of four categories, which determine
* its place in the parse tree. We use the two high bits of the
* (unsigned char) value to store a NODE_TYPE code.
*/
#define NODE_TYPE 0xC0
/*
* The four category values are LEAF, UNARY, and BINARY, explained below,
* and "uncategorized", which is used either temporarily, until context
* determines which of the other three categories is correct, or for
* lexemes like INVALID, which aren't really lexemes at all, but indicators
* of a parsing error. Note that the codes must be distinct to distinguish
* categories, but need not take the form of a bit array.
*/
#define BINARY 0x40 /* This lexeme is a binary operator. An
* OpNode representing it should go into the
* parse tree, and two operands should be
* parsed for it in the expression. */
#define UNARY 0x80 /* This lexeme is a unary operator. An OpNode
* representing it should go into the parse
* tree, and one operand should be parsed for
* it in the expression. */
#define LEAF 0xC0 /* This lexeme is a leaf operand in the parse
* tree. No OpNode will be placed in the tree
* for it. Either a literal value will be
* appended to the list of literals in this
* expression, or appropriate Tcl_Tokens will
* be appended in a Tcl_Parse struct to
* represent those leaves that require some
* form of substitution.
*/
/* Uncategorized lexemes */
#define PLUS 1 /* Ambiguous. Resolves to UNARY_PLUS or
* BINARY_PLUS according to context. */
#define MINUS 2 /* Ambiguous. Resolves to UNARY_MINUS or
* BINARY_MINUS according to context. */
#define BAREWORD 3 /* Ambigous. Resolves to BOOLEAN or to
* FUNCTION or a parse error according to
* context and value. */
#define INCOMPLETE 4 /* A parse error. Used only when the single
* "=" is encountered. */
#define INVALID 5 /* A parse error. Used when any punctuation
* appears that's not a supported operator. */
/* Leaf lexemes */
#define NUMBER ( LEAF | 1) /* For literal numbers */
#define SCRIPT ( LEAF | 2) /* Script substitution; [foo] */
#define BOOLEAN ( LEAF | BAREWORD) /* For literal booleans */
#define BRACED ( LEAF | 4) /* Braced string; {foo bar} */
#define VARIABLE ( LEAF | 5) /* Variable substitution; $x */
#define QUOTED ( LEAF | 6) /* Quoted string; "foo $bar [soom]" */
#define EMPTY ( LEAF | 7) /* Used only for an empty argument
* list to a function. Represents
* the empty string within parens in
* the expression: rand() */
/* Unary operator lexemes */
#define UNARY_PLUS ( UNARY | PLUS)
#define UNARY_MINUS ( UNARY | MINUS)
#define FUNCTION ( UNARY | BAREWORD) /* This is a bit of "creative
* interpretation" on the part of the
* parser. A function call is parsed
* into the parse tree according to
* the perspective that the function
* name is a unary operator and its
* argument list, enclosed in parens,
* is its operand. The additional
* requirements not implied generally
* by treatment as a unary operator --
* for example, the requirement that
* the operand be enclosed in parens --
* are hard coded in the relevant
* portions of ParseExpr(). We trade
* off the need to include such
* exceptional handling in the code
* against the need we would otherwise
* have for more lexeme categories. */
#define START ( UNARY | 4) /* This lexeme isn't parsed from the
* expression text at all. It
* represents the start of the
* expression and sits at the root of
* the parse tree where it serves as
* the start/end point of traversals. */
#define OPEN_PAREN ( UNARY | 5) /* Another bit of creative
* interpretation, where we treat "("
* as a unary operator with the
* sub-expression between it and its
* matching ")" as its operand. See
* CLOSE_PAREN below. */
#define NOT ( UNARY | 6)
#define BIT_NOT ( UNARY | 7)
/* Binary operator lexemes */
#define BINARY_PLUS ( BINARY | PLUS)
#define BINARY_MINUS ( BINARY | MINUS)
#define COMMA ( BINARY | 3) /* The "," operator is a low precedence
* binary operator that separates the
* arguments in a function call. The
* additional constraint that this
* operator can only legally appear
* at the right places within a
* function call argument list are
* hard coded within ParseExpr(). */
#define MULT ( BINARY | 4)
#define DIVIDE ( BINARY | 5)
#define MOD ( BINARY | 6)
#define LESS ( BINARY | 7)
#define GREATER ( BINARY | 8)
#define BIT_AND ( BINARY | 9)
#define BIT_XOR ( BINARY | 10)
#define BIT_OR ( BINARY | 11)
#define QUESTION ( BINARY | 12) /* These two lexemes make up the */
#define COLON ( BINARY | 13) /* ternary conditional operator,
* $x ? $y : $z . We treat them as
* two binary operators to avoid
* another lexeme category, and
* code the additional constraints
* directly in ParseExpr(). For
* instance, the right operand of
* a "?" operator must be a ":"
* operator. */
#define LEFT_SHIFT ( BINARY | 14)
#define RIGHT_SHIFT ( BINARY | 15)
#define LEQ ( BINARY | 16)
#define GEQ ( BINARY | 17)
#define EQUAL ( BINARY | 18)
#define NEQ ( BINARY | 19)
#define AND ( BINARY | 20)
#define OR ( BINARY | 21)
#define STREQ ( BINARY | 22)
#define STRNEQ ( BINARY | 23)
#define EXPON ( BINARY | 24) /* Unlike the other binary operators,
* EXPON is right associative and this
* distinction is coded directly in
* ParseExpr(). */
#define IN_LIST ( BINARY | 25)
#define NOT_IN_LIST ( BINARY | 26)
#define CLOSE_PAREN ( BINARY | 27) /* By categorizing the CLOSE_PAREN
* lexeme as a BINARY operator, the
* normal parsing rules for binary
* operators assure that a close paren
* will not directly follow another
* operator, and the machinery already
* in place to connect operands to
* operators according to precedence
* performs most of the work of
* matching open and close parens for
* us. In the end though, a close
* paren is not really a binary
* operator, and some special coding
* in ParseExpr() make sure we never
* put an actual CLOSE_PAREN node
* in the parse tree. The
* sub-expression between parens
* becomes the single argument of
* the matching OPEN_PAREN unary
* operator. */
#define END ( BINARY | 28) /* This lexeme represents the end of
* the string being parsed. Treating
* it as a binary operator follows the
* same logic as the CLOSE_PAREN lexeme
* and END pairs with START, in the
* same way that CLOSE_PAREN pairs with
* OPEN_PAREN. */
/*
* When ParseExpr() builds the parse tree it must choose which operands to
* connect to which operators. This is done according to operator precedence.
* The greater an operator's precedence the greater claim it has to link to
* an available operand. The Precedence enumeration lists the precedence
* values used by Tcl expression operators, from lowest to highest claim.
* Each precedence level is commented with the operators that hold that
* precedence.
*/
enum Precedence {
PREC_END = 1, /* END */
PREC_START, /* START */
PREC_CLOSE_PAREN, /* ")" */
PREC_OPEN_PAREN, /* "(" */
PREC_COMMA, /* "," */
PREC_CONDITIONAL, /* "?", ":" */
PREC_OR, /* "||" */
PREC_AND, /* "&&" */
PREC_BIT_OR, /* "|" */
PREC_BIT_XOR, /* "^" */
PREC_BIT_AND, /* "&" */
PREC_EQUAL, /* "==", "!=", "eq", "ne", "in", "ni" */
PREC_COMPARE, /* "<", ">", "<=", ">=" */
PREC_SHIFT, /* "<<", ">>" */
PREC_ADD, /* "+", "-" */
PREC_MULT, /* "*", "/", "%" */
PREC_EXPON, /* "**" */
PREC_UNARY /* "+", "-", FUNCTION, "!", "~" */
};
/*
* Here the same information contained in the comments above is stored
* in inverted form, so that given a lexeme, one can quickly look up
* its precedence value.
*/
static const unsigned char prec[] = {
/* Non-operator lexemes */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0,
/* Binary operator lexemes */
PREC_ADD, /* BINARY_PLUS */
PREC_ADD, /* BINARY_MINUS */
PREC_COMMA, /* COMMA */
PREC_MULT, /* MULT */
PREC_MULT, /* DIVIDE */
PREC_MULT, /* MOD */
PREC_COMPARE, /* LESS */
PREC_COMPARE, /* GREATER */
PREC_BIT_AND, /* BIT_AND */
PREC_BIT_XOR, /* BIT_XOR */
PREC_BIT_OR, /* BIT_OR */
PREC_CONDITIONAL, /* QUESTION */
PREC_CONDITIONAL, /* COLON */
PREC_SHIFT, /* LEFT_SHIFT */
PREC_SHIFT, /* RIGHT_SHIFT */
PREC_COMPARE, /* LEQ */
PREC_COMPARE, /* GEQ */
PREC_EQUAL, /* EQUAL */
PREC_EQUAL, /* NEQ */
PREC_AND, /* AND */
PREC_OR, /* OR */
PREC_EQUAL, /* STREQ */
PREC_EQUAL, /* STRNEQ */
PREC_EXPON, /* EXPON */
PREC_EQUAL, /* IN_LIST */
PREC_EQUAL, /* NOT_IN_LIST */
PREC_CLOSE_PAREN, /* CLOSE_PAREN */
PREC_END, /* END */
/* Expansion room for more binary operators */
0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0,
/* Unary operator lexemes */
PREC_UNARY, /* UNARY_PLUS */
PREC_UNARY, /* UNARY_MINUS */
PREC_UNARY, /* FUNCTION */
PREC_START, /* START */
PREC_OPEN_PAREN, /* OPEN_PAREN */
PREC_UNARY, /* NOT*/
PREC_UNARY, /* BIT_NOT*/
};
/*
* The JumpList struct is used to create a stack of data needed for the
* TclEmitForwardJump() and TclFixupForwardJump() calls that are performed
* when compiling the short-circuiting operators QUESTION/COLON, AND, and OR.
* Keeping a stack permits the CompileExprTree() routine to be non-recursive.
*/
typedef struct JumpList {
JumpFixup jump; /* Pass this argument to matching calls of
* TclEmitForwardJump() and
* TclFixupForwardJump(). */
int depth; /* Remember the currStackDepth of the
* CompileEnv here. */
int offset; /* Data used to compute jump lengths to pass
* to TclFixupForwardJump() */
int convert; /* Temporary storage used to compute whether
* numeric conversion will be needed following
* the operator we're compiling. */
struct JumpList *next; /* Point to next item on the stack */
} JumpList;
/*
* Declarations for local functions to this file:
*/
static void CompileExprTree(Tcl_Interp *interp, OpNode *nodes,
Tcl_Obj *const litObjv[], Tcl_Obj *funcList,
Tcl_Token *tokenPtr, int *convertPtr,
CompileEnv *envPtr);
static void ConvertTreeToTokens(const char *start, int numBytes,
OpNode *nodes, Tcl_Token *tokenPtr,
Tcl_Parse *parsePtr);
static int CopyTokens(Tcl_Token *sourcePtr, Tcl_Parse *parsePtr);
static int GenerateTokensForLiteral(const char *script,
int numBytes, Tcl_Parse *parsePtr);
static int ParseExpr(Tcl_Interp *interp, const char *start,
int numBytes, OpNode **opTreePtr,
Tcl_Obj *litList, Tcl_Obj *funcList,
Tcl_Parse *parsePtr, int parseOnly);
static int ParseLexeme(const char *start, int numBytes,
unsigned char *lexemePtr, Tcl_Obj **literalPtr);
/*
*----------------------------------------------------------------------
*
* ParseExpr --
*
* Given a string, the numBytes bytes starting at start, this function
* parses it as a Tcl expression and constructs a tree representing
* the structure of the expression. The caller must pass in empty
* lists as the funcList and litList arguments. The elements of the
* parsed expression are returned to the caller as that tree, a list of
* literal values, a list of function names, and in Tcl_Tokens
* added to a Tcl_Parse struct passed in by the caller.
*
* Results:
* If the string is successfully parsed as a valid Tcl expression, TCL_OK
* is returned, and data about the expression structure is written to
* the last four arguments. If the string cannot be parsed as a valid
* Tcl expression, TCL_ERROR is returned, and if interp is non-NULL, an
* error message is written to interp.
*
* Side effects:
* Memory will be allocated. If TCL_OK is returned, the caller must
* clean up the returned data structures. The (OpNode *) value written
* to opTreePtr should be passed to ckfree() and the parsePtr argument
* should be passed to Tcl_FreeParse(). The elements appended to the
* litList and funcList will automatically be freed whenever the
* refcount on those lists indicates they can be freed.
*
*----------------------------------------------------------------------
*/
static int
ParseExpr(
Tcl_Interp *interp, /* Used for error reporting. */
const char *start, /* Start of source string to parse. */
int numBytes, /* Number of bytes in string. */
OpNode **opTreePtr, /* Points to space where a pointer to the
* allocated OpNode tree should go. */
Tcl_Obj *litList, /* List to append literals to. */
Tcl_Obj *funcList, /* List to append function names to. */
Tcl_Parse *parsePtr, /* Structure to fill with tokens representing
* those operands that require run time
* substitutions. */
int parseOnly) /* A boolean indicating whether the caller's
* aim is just a parse, or whether it will go
* on to compile the expression. Different
* optimizations are appropriate for the
* two scenarios. */
{
OpNode *nodes = NULL; /* Pointer to the OpNode storage array where
* we build the parse tree. */
int nodesAvailable = 64; /* Initial size of the storage array. This
* value establishes a minimum tree memory cost
* of only about 1 kibyte, and is large enough
* for most expressions to parse with no need
* for array growth and reallocation. */
int nodesUsed = 0; /* Number of OpNodes filled. */
int scanned = 0; /* Capture number of byte scanned by
* parsing routines. */
int lastParsed; /* Stores info about what the lexeme parsed
* the previous pass through the parsing loop
* was. If it was an operator, lastParsed is
* the index of the OpNode for that operator.
* If it was not an operator, lastParsed holds
* an OperandTypes value encoding what we
* need to know about it. */
int incomplete; /* Index of the most recent incomplete tree
* in the OpNode array. Heads a stack of
* incomplete trees linked by p.prev. */
int complete = OT_NONE; /* "Index" of the complete tree (that is, a
* complete subexpression) determined at the
* moment. OT_NONE is a nonsense value
* used only to silence compiler warnings.
* During a parse, complete will always hold
* an index or an OperandTypes value pointing
* to an actual leaf at the time the complete
* tree is needed. */
/* These variables control generation of the error message. */
Tcl_Obj *msg = NULL; /* The error message. */
Tcl_Obj *post = NULL; /* In a few cases, an additional postscript
* for the error message, supplying more
* information after the error msg and
* location have been reported. */
const char *mark = "_@_"; /* In the portion of the complete error message
* where the error location is reported, this
* "mark" substring is inserted into the
* string being parsed to aid in pinpointing
* the location of the syntax error in the
* expression. */
int insertMark = 0; /* A boolean controlling whether the "mark"
* should be inserted. */
const int limit = 25; /* Portions of the error message are
* constructed out of substrings of the
* original expression. In order to keep the
* error message readable, we impose this limit
* on the substring size we extract. */
TclParseInit(interp, start, numBytes, parsePtr);
nodes = (OpNode *) attemptckalloc(nodesAvailable * sizeof(OpNode));
if (nodes == NULL) {
TclNewLiteralStringObj(msg, "not enough memory to parse expression");
goto error;
}
/* Initialize the parse tree with the special "START" node. */
nodes->lexeme = START;
nodes->precedence = prec[START];
nodes->left = OT_NONE;
nodes->right = OT_NONE;
incomplete = lastParsed = nodesUsed;
nodesUsed++;
/*
* Main parsing loop parses one lexeme per iteration. We exit the
* loop only when there's a syntax error with a "goto error" which
* takes us to the error handling code following the loop, or when
* we've successfully completed the parse and we return to the caller.
*/
while (1) {
OpNode *nodePtr; /* Points to the OpNode we may fill this
* pass through the loop. */
unsigned char lexeme; /* The lexeme we parse this iteration. */
Tcl_Obj *literal; /* Filled by the ParseLexeme() call when
* a literal is parsed that has a Tcl_Obj
* rep worth preserving. */
const char *lastStart = start - scanned;
/* Compute where the lexeme parsed the
* previous pass through the loop began.
* This is helpful for detecting invalid
* octals and providing more complete error
* messages. */
/*
* Each pass through this loop adds up to one more OpNode. Allocate
* space for one if required.
*/
if (nodesUsed >= nodesAvailable) {
int size = nodesUsed * 2;
OpNode *newPtr;
do {
newPtr = (OpNode *) attemptckrealloc((char *) nodes,
(unsigned int) size * sizeof(OpNode));
} while ((newPtr == NULL)
&& ((size -= (size - nodesUsed) / 2) > nodesUsed));
if (newPtr == NULL) {
TclNewLiteralStringObj(msg,
"not enough memory to parse expression");
goto error;
}
nodesAvailable = size;
nodes = newPtr;
}
nodePtr = nodes + nodesUsed;
/* Skip white space between lexemes. */
scanned = TclParseAllWhiteSpace(start, numBytes);
start += scanned;
numBytes -= scanned;
scanned = ParseLexeme(start, numBytes, &lexeme, &literal);
/* Use context to categorize the lexemes that are ambiguous. */
if ((NODE_TYPE & lexeme) == 0) {
switch (lexeme) {
case INVALID:
msg = Tcl_ObjPrintf(
"invalid character \"%.*s\"", scanned, start);
goto error;
case INCOMPLETE:
msg = Tcl_ObjPrintf(
"incomplete operator \"%.*s\"", scanned, start);
goto error;
case BAREWORD:
/*
* Most barewords in an expression are a syntax error.
* The exceptions are that when a bareword is followed by
* an open paren, it might be a function call, and when the
* bareword is a legal literal boolean value, we accept that
* as well.
*/
if (start[scanned+TclParseAllWhiteSpace(
start+scanned, numBytes-scanned)] == '(') {
lexeme = FUNCTION;
/*
* When we compile the expression we'll need the function
* name, and there's no place in the parse tree to store
* it, so we keep a separate list of all the function
* names we've parsed in the order we found them.
*/
Tcl_ListObjAppendElement(NULL, funcList, literal);
} else {
int b;
if (Tcl_GetBooleanFromObj(NULL, literal, &b) == TCL_OK) {
lexeme = BOOLEAN;
} else {
Tcl_DecrRefCount(literal);
msg = Tcl_ObjPrintf(
"invalid bareword \"%.*s%s\"",
(scanned < limit) ? scanned : limit - 3, start,
(scanned < limit) ? "" : "...");
post = Tcl_ObjPrintf(
"should be \"$%.*s%s\" or \"{%.*s%s}\"",
(scanned < limit) ? scanned : limit - 3,
start, (scanned < limit) ? "" : "...",
(scanned < limit) ? scanned : limit - 3,
start, (scanned < limit) ? "" : "...");
Tcl_AppendPrintfToObj(post,
" or \"%.*s%s(...)\" or ...",
(scanned < limit) ? scanned : limit - 3,
start, (scanned < limit) ? "" : "...");
goto error;
}
}
break;
case PLUS:
case MINUS:
if (IsOperator(lastParsed)) {
/*
* A "+" or "-" coming just after another operator
* must be interpreted as a unary operator.
*/
lexeme |= UNARY;
} else {
lexeme |= BINARY;
}
}
} /* Uncategorized lexemes */
/* Handle lexeme based on its category. */
switch (NODE_TYPE & lexeme) {
/*
* Each LEAF results in either a literal getting appended to the
* litList, or a sequence of Tcl_Tokens representing a Tcl word
* getting appended to the parsePtr->tokens. No OpNode is filled
* for this lexeme.
*/
case LEAF: {
Tcl_Token *tokenPtr;
const char *end = start;
int wordIndex;
int code = TCL_OK;
/*
* A leaf operand appearing just after something that's not an
* operator is a syntax error.
*/
if (NotOperator(lastParsed)) {
msg = Tcl_ObjPrintf("missing operator at %s", mark);
if (lastStart[0] == '0') {
Tcl_Obj *copy = Tcl_NewStringObj(lastStart,
start + scanned - lastStart);
if (TclCheckBadOctal(NULL, Tcl_GetString(copy))) {
TclNewLiteralStringObj(post,
"looks like invalid octal number");
}
Tcl_DecrRefCount(copy);
}
scanned = 0;
insertMark = 1;
parsePtr->errorType = TCL_PARSE_BAD_NUMBER;
/* Free any literal to avoid a memleak. */
if ((lexeme == NUMBER) || (lexeme == BOOLEAN)) {
Tcl_DecrRefCount(literal);
}
goto error;
}
switch (lexeme) {
case NUMBER:
case BOOLEAN:
Tcl_ListObjAppendElement(NULL, litList, literal);
complete = lastParsed = OT_LITERAL;
start += scanned;
numBytes -= scanned;
continue;
default:
break;
}
/*
* Remaining LEAF cases may involve filling Tcl_Tokens, so
* make room for at least 2 more tokens.
*/
TclGrowParseTokenArray(parsePtr, 2);
wordIndex = parsePtr->numTokens;
tokenPtr = parsePtr->tokenPtr + wordIndex;
tokenPtr->type = TCL_TOKEN_WORD;
tokenPtr->start = start;
parsePtr->numTokens++;
switch (lexeme) {
case QUOTED:
code = Tcl_ParseQuotedString(interp, start, numBytes,
parsePtr, 1, &end);
scanned = end - start;
break;
case BRACED:
code = Tcl_ParseBraces(interp, start, numBytes,
parsePtr, 1, &end);
scanned = end - start;
break;
case VARIABLE:
code = Tcl_ParseVarName(interp, start, numBytes, parsePtr, 1);
/*
* Handle the quirk that Tcl_ParseVarName reports a successful
* parse even when it gets only a "$" with no variable name.
*/
tokenPtr = parsePtr->tokenPtr + wordIndex + 1;
if (code == TCL_OK && tokenPtr->type != TCL_TOKEN_VARIABLE) {
TclNewLiteralStringObj(msg, "invalid character \"$\"");
goto error;
}
scanned = tokenPtr->size;
break;
case SCRIPT: {
Tcl_Parse *nestedPtr =
(Tcl_Parse *) TclStackAlloc(interp, sizeof(Tcl_Parse));
tokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
tokenPtr->type = TCL_TOKEN_COMMAND;
tokenPtr->start = start;
tokenPtr->numComponents = 0;
end = start + numBytes;
start++;
while (1) {
code = Tcl_ParseCommand(interp, start, (end - start), 1,
nestedPtr);
if (code != TCL_OK) {
parsePtr->term = nestedPtr->term;
parsePtr->errorType = nestedPtr->errorType;
parsePtr->incomplete = nestedPtr->incomplete;
break;
}
start = (nestedPtr->commandStart + nestedPtr->commandSize);
Tcl_FreeParse(nestedPtr);
if ((nestedPtr->term < end) && (*(nestedPtr->term) == ']')
&& !(nestedPtr->incomplete)) {
break;
}
if (start == end) {
TclNewLiteralStringObj(msg, "missing close-bracket");
parsePtr->term = tokenPtr->start;
parsePtr->errorType = TCL_PARSE_MISSING_BRACKET;
parsePtr->incomplete = 1;
code = TCL_ERROR;
break;
}
}
TclStackFree(interp, nestedPtr);
end = start;
start = tokenPtr->start;
scanned = end - start;
tokenPtr->size = scanned;
parsePtr->numTokens++;
break;
}
}
if (code != TCL_OK) {
/*
* Here we handle all the syntax errors generated by
* the Tcl_Token generating parsing routines called in the
* switch just above. If the value of parsePtr->incomplete
* is 1, then the error was an unbalanced '[', '(', '{',
* or '"' and parsePtr->term is pointing to that unbalanced
* character. If the value of parsePtr->incomplete is 0,
* then the error is one of lacking whitespace following a
* quoted word, for example: expr {[an error {foo}bar]},
* and parsePtr->term points to where the whitespace is
* missing. We reset our values of start and scanned so that
* when our error message is constructed, the location of
* the syntax error is sure to appear in it, even if the
* quoted expression is truncated.
*/
start = parsePtr->term;
scanned = parsePtr->incomplete;
goto error;
}
tokenPtr = parsePtr->tokenPtr + wordIndex;
tokenPtr->size = scanned;
tokenPtr->numComponents = parsePtr->numTokens - wordIndex - 1;
if (!parseOnly && ((lexeme == QUOTED) || (lexeme == BRACED))) {
/*
* When this expression is destined to be compiled, and a
* braced or quoted word within an expression is known at
* compile time (no runtime substitutions in it), we can
* store it as a literal rather than in its tokenized form.
* This is an advantage since the compiled bytecode is going
* to need the argument in Tcl_Obj form eventually, so it's
* just as well to get there now. Another advantage is that
* with this conversion, larger constant expressions might
* be grown and optimized.
*
* On the contrary, if the end goal of this parse is to
* fill a Tcl_Parse for a caller of Tcl_ParseExpr(), then it's
* wasteful to convert to a literal only to convert back again
* later.
*/
literal = Tcl_NewObj();
if (TclWordKnownAtCompileTime(tokenPtr, literal)) {
Tcl_ListObjAppendElement(NULL, litList, literal);
complete = lastParsed = OT_LITERAL;
parsePtr->numTokens = wordIndex;
break;
}
Tcl_DecrRefCount(literal);
}
complete = lastParsed = OT_TOKENS;
break;
} /* case LEAF */
case UNARY:
/*
* A unary operator appearing just after something that's not an
* operator is a syntax error -- something trying to be the left
* operand of an operator that doesn't take one.
*/
if (NotOperator(lastParsed)) {
msg = Tcl_ObjPrintf("missing operator at %s", mark);
scanned = 0;
insertMark = 1;
goto error;
}
/* Create an OpNode for the unary operator */
nodePtr->lexeme = lexeme; /* Remember the operator... */
nodePtr->precedence = prec[lexeme]; /* ... and its precedence. */
nodePtr->left = OT_NONE; /* No left operand */
nodePtr->right = OT_NONE; /* Right operand not
* yet known. */
/*
* This unary operator is a new incomplete tree, so push it
* onto our stack of incomplete trees. Also remember it as
* the last lexeme we parsed.
*/
nodePtr->p.prev = incomplete;
incomplete = lastParsed = nodesUsed;
nodesUsed++;
break;
case BINARY: {
OpNode *incompletePtr;
unsigned char precedence = prec[lexeme];
/*
* A binary operator appearing just after another operator is a
* syntax error -- one of the two operators is missing an operand.
*/
if (IsOperator(lastParsed)) {
if ((lexeme == CLOSE_PAREN)
&& (nodePtr[-1].lexeme == OPEN_PAREN)) {
if (nodePtr[-2].lexeme == FUNCTION) {
/*
* Normally, "()" is a syntax error, but as a special
* case accept it as an argument list for a function.
* Treat this as a special LEAF lexeme, and restart
* the parsing loop with zero characters scanned.
* We'll parse the ")" again the next time through,
* but with the OT_EMPTY leaf as the subexpression
* between the parens.
*/
scanned = 0;
complete = lastParsed = OT_EMPTY;
/* TODO: explain */
nodePtr[-1].left--;
break;
}
msg = Tcl_ObjPrintf("empty subexpression at %s", mark);
scanned = 0;
insertMark = 1;
goto error;
}
if (nodePtr[-1].precedence > precedence) {
if (nodePtr[-1].lexeme == OPEN_PAREN) {
TclNewLiteralStringObj(msg, "unbalanced open paren");
parsePtr->errorType = TCL_PARSE_MISSING_PAREN;
} else if (nodePtr[-1].lexeme == COMMA) {
msg = Tcl_ObjPrintf(
"missing function argument at %s", mark);
scanned = 0;
insertMark = 1;
} else if (nodePtr[-1].lexeme == START) {
TclNewLiteralStringObj(msg, "empty expression");
}
} else {
if (lexeme == CLOSE_PAREN) {
TclNewLiteralStringObj(msg, "unbalanced close paren");
} else if ((lexeme == COMMA)
&& (nodePtr[-1].lexeme == OPEN_PAREN)
&& (nodePtr[-2].lexeme == FUNCTION)) {
msg = Tcl_ObjPrintf(
"missing function argument at %s", mark);
scanned = 0;
insertMark = 1;
}
}
if (msg == NULL) {
msg = Tcl_ObjPrintf("missing operand at %s", mark);
scanned = 0;
insertMark = 1;
}
goto error;
}
/*
* Here is where the tree comes together. At this point, we
* have a stack of incomplete trees corresponding to
* substrings that are incomplete expressions, followed by
* a complete tree corresponding to a substring that is itself
* a complete expression, followed by the binary operator we have
* just parsed. The incomplete trees can each be completed by
* adding a right operand.
*
* To illustrate with an example, when we parse the expression
* "1+2*3-4" and we reach this point having just parsed the "-"
* operator, we have these incomplete trees: START, "1+", and
* "2*". Next we have the complete subexpression "3". Last is
* the "-" we've just parsed.
*
* The next step is to join our complete tree to an operator.
* The choice is governed by the precedence and associativity
* of the competing operators. If we connect it as the right
* operand of our most recent incomplete tree, we get a new
* complete tree, and we can repeat the process. The while
* loop following repeats this until precedence indicates it
* is time to join the complete tree as the left operand of
* the just parsed binary operator.
*
* Continuing the example, the first pass through the loop
* will join "3" to "2*"; the next pass will join "2*3" to
* "1+". Then we'll exit the loop and join "1+2*3" to "-".
* When we return to parse another lexeme, our stack of
* incomplete trees is START and "1+2*3-".
*/
while (1) {
incompletePtr = nodes + incomplete;
if (incompletePtr->precedence < precedence) {
break;
}
if (incompletePtr->precedence == precedence) {
/* Right association rules for exponentiation. */
if (lexeme == EXPON) {
break;
}
/*
* Special association rules for the conditional operators.
* The "?" and ":" operators have equal precedence, but
* must be linked up in sensible pairs.
*/
if ((incompletePtr->lexeme == QUESTION)
&& (NotOperator(complete)
|| (nodes[complete].lexeme != COLON))) {
break;
}
if ((incompletePtr->lexeme == COLON)
&& (lexeme == QUESTION)) {
break;
}
}
/* Some special syntax checks... */
/* Parens must balance */
if ((incompletePtr->lexeme == OPEN_PAREN)
&& (lexeme != CLOSE_PAREN)) {
TclNewLiteralStringObj(msg, "unbalanced open paren");
parsePtr->errorType = TCL_PARSE_MISSING_PAREN;
goto error;
}
/* Right operand of "?" must be ":" */
if ((incompletePtr->lexeme == QUESTION)
&& (NotOperator(complete)
|| (nodes[complete].lexeme != COLON))) {
msg = Tcl_ObjPrintf(
"missing operator \":\" at %s", mark);
scanned = 0;
insertMark = 1;
goto error;
}
/* Operator ":" may only be right operand of "?" */
if (IsOperator(complete)
&& (nodes[complete].lexeme == COLON)
&& (incompletePtr->lexeme != QUESTION)) {
TclNewLiteralStringObj(msg,
"unexpected operator \":\" "
"without preceding \"?\"");
goto error;
}
/*
* Attach complete tree as right operand of most recent
* incomplete tree.
*/
incompletePtr->right = complete;
if (IsOperator(complete)) {
nodes[complete].p.parent = incomplete;
}
if (incompletePtr->lexeme == START) {
/*
* Completing the START tree indicates we're done.
* Transfer the parse tree to the caller and return.
*/
*opTreePtr = nodes;
return TCL_OK;
}
/*
* With a right operand attached, last incomplete tree has
* become the complete tree. Pop it from the incomplete
* tree stack.
*/
complete = incomplete;
incomplete = incompletePtr->p.prev;
/* CLOSE_PAREN can only close one OPEN_PAREN. */
if (incompletePtr->lexeme == OPEN_PAREN) {
break;
}
}
/* More syntax checks... */
/* Parens must balance. */
if (lexeme == CLOSE_PAREN) {
if (incompletePtr->lexeme != OPEN_PAREN) {
TclNewLiteralStringObj(msg, "unbalanced close paren");
goto error;
}
}
/* Commas must appear only in function argument lists. */
if (lexeme == COMMA) {
if ((incompletePtr->lexeme != OPEN_PAREN)
|| (incompletePtr[-1].lexeme != FUNCTION)) {
TclNewLiteralStringObj(msg,
"unexpected \",\" outside function argument list");
goto error;
}
/* TODO: explain */
incompletePtr->left++;
}
/* Operator ":" may only be right operand of "?" */
if (IsOperator(complete) && (nodes[complete].lexeme == COLON)) {
TclNewLiteralStringObj(msg,
"unexpected operator \":\" without preceding \"?\"");
goto error;
}
/* Create no node for a CLOSE_PAREN lexeme. */
if (lexeme == CLOSE_PAREN) {
/* TODO: explain */
incompletePtr->left++;
break;
}
/* Link complete tree as left operand of new node. */
nodePtr->lexeme = lexeme;
nodePtr->precedence = precedence;
nodePtr->right = OT_NONE;
nodePtr->left = complete;
if (IsOperator(complete)) {
nodes[complete].p.parent = nodesUsed;
}
/*
* With a left operand attached and a right operand missing,
* the just-parsed binary operator is root of a new incomplete
* tree. Push it onto the stack of incomplete trees.
*/
nodePtr->p.prev = incomplete;
incomplete = lastParsed = nodesUsed;
nodesUsed++;
break;
} /* case BINARY */
} /* lexeme handler */
/* Advance past the just-parsed lexeme */
start += scanned;
numBytes -= scanned;
} /* main parsing loop */
error:
/*
* We only get here if there's been an error.
* Any errors that didn't get a suitable parsePtr->errorType,
* get recorded as syntax errors.
*/
if (parsePtr->errorType == TCL_PARSE_SUCCESS) {
parsePtr->errorType = TCL_PARSE_SYNTAX;
}
/* Free any partial parse tree we've built. */
if (nodes != NULL) {
ckfree((char*) nodes);
}
if (interp == NULL) {
/* Nowhere to report an error message, so just free it */
if (msg) {
Tcl_DecrRefCount(msg);
}
} else {
/*
* Construct the complete error message. Start with the simple
* error message, pulled from the interp result if necessary...
*/
if (msg == NULL) {
msg = Tcl_GetObjResult(interp);
}
/*
* Add a detailed quote from the bad expression, displaying and
* sometimes marking the precise location of the syntax error.
*/
Tcl_AppendPrintfToObj(msg, "\nin expression \"%s%.*s%.*s%s%s%.*s%s\"",
((start - limit) < parsePtr->string) ? "" : "...",
((start - limit) < parsePtr->string)
? (start - parsePtr->string) : limit - 3,
((start - limit) < parsePtr->string)
? parsePtr->string : start - limit + 3,
(scanned < limit) ? scanned : limit - 3, start,
(scanned < limit) ? "" : "...", insertMark ? mark : "",
(start + scanned + limit > parsePtr->end)
? parsePtr->end - (start + scanned) : limit-3,
start + scanned,
(start + scanned + limit > parsePtr->end) ? "" : "...");
/* Next, append any postscript message. */
if (post != NULL) {
Tcl_AppendToObj(msg, ";\n", -1);
Tcl_AppendObjToObj(msg, post);
Tcl_DecrRefCount(post);
}
Tcl_SetObjResult(interp, msg);
/* Finally, place context information in the errorInfo. */
numBytes = parsePtr->end - parsePtr->string;
Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
"\n (parsing expression \"%.*s%s\")",
(numBytes < limit) ? numBytes : limit - 3,
parsePtr->string, (numBytes < limit) ? "" : "..."));
}
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* GenerateTokensForLiteral --
*
* Results:
* Number of bytes scanned.
*
* Side effects:
* The Tcl_Parse *parsePtr is filled with Tcl_Tokens representing the
* literal.
*
*----------------------------------------------------------------------
*/
static int
GenerateTokensForLiteral(
const char *script,
int numBytes,
Tcl_Parse *parsePtr)
{
int scanned;
const char *start = script;
Tcl_Token *destPtr;
unsigned char lexeme;
/* Have to reparse to get pointers into source string. */
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
scanned = ParseLexeme(start, numBytes-scanned, &lexeme, NULL);
TclGrowParseTokenArray(parsePtr, 2);
destPtr = parsePtr->tokenPtr + parsePtr->numTokens;
destPtr->type = TCL_TOKEN_SUB_EXPR;
destPtr->start = start;
destPtr->size = scanned;
destPtr->numComponents = 1;
destPtr++;
destPtr->type = TCL_TOKEN_TEXT;
destPtr->start = start;
destPtr->size = scanned;
destPtr->numComponents = 0;
parsePtr->numTokens += 2;
return (start + scanned - script);
}
/*
*----------------------------------------------------------------------
*
* CopyTokens --
*
* Results:
* Number of bytes scanned.
*
* Side effects:
* The Tcl_Parse *parsePtr is filled with Tcl_Tokens representing the
* literal.
*
*----------------------------------------------------------------------
*/
static int
CopyTokens(
Tcl_Token *sourcePtr,
Tcl_Parse *parsePtr)
{
int toCopy = sourcePtr->numComponents + 1;
Tcl_Token *destPtr;
if (sourcePtr->numComponents == sourcePtr[1].numComponents + 1) {
TclGrowParseTokenArray(parsePtr, toCopy);
destPtr = parsePtr->tokenPtr + parsePtr->numTokens;
memcpy(destPtr, sourcePtr, (size_t) toCopy * sizeof(Tcl_Token));
destPtr->type = TCL_TOKEN_SUB_EXPR;
parsePtr->numTokens += toCopy;
} else {
TclGrowParseTokenArray(parsePtr, toCopy - 1);
destPtr = parsePtr->tokenPtr + parsePtr->numTokens;
*destPtr = *sourcePtr;
destPtr->type = TCL_TOKEN_SUB_EXPR;
destPtr->numComponents++;
destPtr++;
memcpy(destPtr, sourcePtr, (size_t) toCopy * sizeof(Tcl_Token));
parsePtr->numTokens += toCopy + 1;
}
return toCopy;
}
/*
*----------------------------------------------------------------------
*
* ConvertTreeToTokens --
*
* Results:
* None.
*
* Side effects:
* The Tcl_Parse *parsePtr is filled with Tcl_Tokens representing the
* parsed expression.
*
*----------------------------------------------------------------------
*/
static void
ConvertTreeToTokens(
const char *start,
int numBytes,
OpNode *nodes,
Tcl_Token *tokenPtr,
Tcl_Parse *parsePtr)
{
OpNode *nodePtr = nodes;
int scanned, copied, tokenIdx;
unsigned char lexeme;
Tcl_Token *destPtr;
while (1) {
switch (NODE_TYPE & nodePtr->lexeme) {
case UNARY:
if (nodePtr->right > OT_NONE) {
int right = nodePtr->right;
nodePtr->right = OT_NONE;
if (nodePtr->lexeme != START) {
/*
* Find operator in string.
*/
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
scanned = ParseLexeme(start, numBytes, &lexeme, NULL);
if (lexeme != nodePtr->lexeme) {
if (lexeme != (nodePtr->lexeme & ~NODE_TYPE)) {
Tcl_Panic("lexeme mismatch");
}
}
if (nodePtr->lexeme != OPEN_PAREN) {
TclGrowParseTokenArray(parsePtr, 2);
nodePtr->right = OT_NONE - parsePtr->numTokens;
destPtr = parsePtr->tokenPtr + parsePtr->numTokens;
destPtr->type = TCL_TOKEN_SUB_EXPR;
destPtr->start = start;
destPtr++;
destPtr->type = TCL_TOKEN_OPERATOR;
destPtr->start = start;
destPtr->size = scanned;
destPtr->numComponents = 0;
parsePtr->numTokens += 2;
}
start += scanned;
numBytes -= scanned;
}
switch (right) {
case OT_EMPTY:
break;
case OT_LITERAL:
scanned = GenerateTokensForLiteral(start, numBytes,
parsePtr);
start +=scanned;
numBytes -= scanned;
break;
case OT_TOKENS:
copied = CopyTokens(tokenPtr, parsePtr);
scanned = tokenPtr->start + tokenPtr->size - start;
start +=scanned;
numBytes -= scanned;
tokenPtr += copied;
break;
default:
nodePtr = nodes + right;
}
} else {
if (nodePtr->lexeme == START) {
/*
* We're done.
*/
return;
}
if (nodePtr->lexeme == OPEN_PAREN) {
/*
* Skip past matching close paren.
*/
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
scanned = ParseLexeme(start, numBytes, &lexeme, NULL);
start +=scanned;
numBytes -= scanned;
} else {
tokenIdx = OT_NONE - nodePtr->right;
nodePtr->right = OT_NONE;
destPtr = parsePtr->tokenPtr + tokenIdx;
destPtr->size = start - destPtr->start;
destPtr->numComponents = parsePtr->numTokens - tokenIdx - 1;
}
nodePtr = nodes + nodePtr->p.parent;
}
break;
case BINARY:
if (nodePtr->left > OT_NONE) {
int left = nodePtr->left;
nodePtr->left = OT_NONE;
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
if ((nodePtr->lexeme != COMMA) && (nodePtr->lexeme != COLON)) {
TclGrowParseTokenArray(parsePtr, 2);
nodePtr->left = OT_NONE - parsePtr->numTokens;
destPtr = parsePtr->tokenPtr + parsePtr->numTokens;
destPtr->type = TCL_TOKEN_SUB_EXPR;
destPtr->start = start;
destPtr++;
destPtr->type = TCL_TOKEN_OPERATOR;
parsePtr->numTokens += 2;
}
switch (left) {
case OT_LITERAL:
scanned = GenerateTokensForLiteral(start, numBytes,
parsePtr);
start +=scanned;
numBytes -= scanned;
break;
case OT_TOKENS:
copied = CopyTokens(tokenPtr, parsePtr);
scanned = tokenPtr->start + tokenPtr->size - start;
start +=scanned;
numBytes -= scanned;
tokenPtr += copied;
break;
default:
nodePtr = nodes + left;
}
} else if (nodePtr->right > OT_NONE) {
int right = nodePtr->right;
nodePtr->right = OT_NONE;
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
scanned = ParseLexeme(start, numBytes, &lexeme, NULL);
if (lexeme != nodePtr->lexeme) {
if (lexeme != (nodePtr->lexeme & ~NODE_TYPE)) {
Tcl_Panic("lexeme mismatch");
}
}
if ((nodePtr->lexeme != COMMA) && (nodePtr->lexeme != COLON)) {
tokenIdx = OT_NONE - nodePtr->left;
destPtr = parsePtr->tokenPtr + tokenIdx + 1;
destPtr->start = start;
destPtr->size = scanned;
destPtr->numComponents = 0;
}
start +=scanned;
numBytes -= scanned;
switch (right) {
case OT_LITERAL:
scanned = GenerateTokensForLiteral(start, numBytes,
parsePtr);
start +=scanned;
numBytes -= scanned;
break;
case OT_TOKENS:
copied = CopyTokens(tokenPtr, parsePtr);
scanned = tokenPtr->start + tokenPtr->size - start;
start +=scanned;
numBytes -= scanned;
tokenPtr += copied;
break;
default:
nodePtr = nodes + right;
}
} else {
if ((nodePtr->lexeme != COMMA) && (nodePtr->lexeme != COLON)) {
tokenIdx = OT_NONE - nodePtr->left;
nodePtr->left = OT_NONE;
destPtr = parsePtr->tokenPtr + tokenIdx;
destPtr->size = start - destPtr->start;
destPtr->numComponents = parsePtr->numTokens-tokenIdx-1;
}
nodePtr = nodes + nodePtr->p.parent;
}
break;
}
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_ParseExpr --
*
* Given a string, the numBytes bytes starting at start, this function
* parses it as a Tcl expression and stores information about the
* structure of the expression in the Tcl_Parse struct indicated by the
* caller.
*
* Results:
* If the string is successfully parsed as a valid Tcl expression, TCL_OK
* is returned, and data about the expression structure is written to
* *parsePtr. If the string cannot be parsed as a valid Tcl expression,
* TCL_ERROR is returned, and if interp is non-NULL, an error message is
* written to interp.
*
* Side effects:
* If there is insufficient space in parsePtr to hold all the information
* about the expression, then additional space is malloc-ed. If the
* function returns TCL_OK then the caller must eventually invoke
* Tcl_FreeParse to release any additional space that was allocated.
*
*----------------------------------------------------------------------
*/
int
Tcl_ParseExpr(
Tcl_Interp *interp, /* Used for error reporting. */
const char *start, /* Start of source string to parse. */
int numBytes, /* Number of bytes in string. If < 0, the
* string consists of all bytes up to the
* first null character. */
Tcl_Parse *parsePtr) /* Structure to fill with information about
* the parsed expression; any previous
* information in the structure is ignored. */
{
int code;
OpNode *opTree = NULL; /* Will point to the tree of operators */
Tcl_Obj *litList = Tcl_NewObj(); /* List to hold the literals */
Tcl_Obj *funcList = Tcl_NewObj(); /* List to hold the functon names*/
Tcl_Parse *exprParsePtr =
(Tcl_Parse *) TclStackAlloc(interp, sizeof(Tcl_Parse));
/* Holds the Tcl_Tokens of substitutions */
if (numBytes < 0) {
numBytes = (start ? strlen(start) : 0);
}
code = ParseExpr(interp, start, numBytes, &opTree, litList,
funcList, exprParsePtr, 1 /* parseOnly */);
Tcl_DecrRefCount(funcList);
Tcl_DecrRefCount(litList);
TclParseInit(interp, start, numBytes, parsePtr);
if (code == TCL_OK) {
ConvertTreeToTokens(start, numBytes,
opTree, exprParsePtr->tokenPtr, parsePtr);
} else {
parsePtr->term = exprParsePtr->term;
parsePtr->errorType = exprParsePtr->errorType;
}
Tcl_FreeParse(exprParsePtr);
TclStackFree(interp, exprParsePtr);
ckfree((char *) opTree);
return code;
}
/*
*----------------------------------------------------------------------
*
* ParseLexeme --
*
* Parse a single lexeme from the start of a string, scanning no more
* than numBytes bytes.
*
* Results:
* Returns the number of bytes scanned to produce the lexeme.
*
* Side effects:
* Code identifying lexeme parsed is writen to *lexemePtr.
*
*----------------------------------------------------------------------
*/
static int
ParseLexeme(
const char *start, /* Start of lexeme to parse. */
int numBytes, /* Number of bytes in string. */
unsigned char *lexemePtr, /* Write code of parsed lexeme to this
* storage. */
Tcl_Obj **literalPtr) /* Write corresponding literal value to this
storage, if non-NULL. */
{
const char *end;
int scanned;
Tcl_UniChar ch;
Tcl_Obj *literal = NULL;
if (numBytes == 0) {
*lexemePtr = END;
return 0;
}
switch (*start) {
case '[':
*lexemePtr = SCRIPT;
return 1;
case '{':
*lexemePtr = BRACED;
return 1;
case '(':
*lexemePtr = OPEN_PAREN;
return 1;
case ')':
*lexemePtr = CLOSE_PAREN;
return 1;
case '$':
*lexemePtr = VARIABLE;
return 1;
case '\"':
*lexemePtr = QUOTED;
return 1;
case ',':
*lexemePtr = COMMA;
return 1;
case '/':
*lexemePtr = DIVIDE;
return 1;
case '%':
*lexemePtr = MOD;
return 1;
case '+':
*lexemePtr = PLUS;
return 1;
case '-':
*lexemePtr = MINUS;
return 1;
case '?':
*lexemePtr = QUESTION;
return 1;
case ':':
*lexemePtr = COLON;
return 1;
case '^':
*lexemePtr = BIT_XOR;
return 1;
case '~':
*lexemePtr = BIT_NOT;
return 1;
case '*':
if ((numBytes > 1) && (start[1] == '*')) {
*lexemePtr = EXPON;
return 2;
}
*lexemePtr = MULT;
return 1;
case '=':
if ((numBytes > 1) && (start[1] == '=')) {
*lexemePtr = EQUAL;
return 2;
}
*lexemePtr = INCOMPLETE;
return 1;
case '!':
if ((numBytes > 1) && (start[1] == '=')) {
*lexemePtr = NEQ;
return 2;
}
*lexemePtr = NOT;
return 1;
case '&':
if ((numBytes > 1) && (start[1] == '&')) {
*lexemePtr = AND;
return 2;
}
*lexemePtr = BIT_AND;
return 1;
case '|':
if ((numBytes > 1) && (start[1] == '|')) {
*lexemePtr = OR;
return 2;
}
*lexemePtr = BIT_OR;
return 1;
case '<':
if (numBytes > 1) {
switch (start[1]) {
case '<':
*lexemePtr = LEFT_SHIFT;
return 2;
case '=':
*lexemePtr = LEQ;
return 2;
}
}
*lexemePtr = LESS;
return 1;
case '>':
if (numBytes > 1) {
switch (start[1]) {
case '>':
*lexemePtr = RIGHT_SHIFT;
return 2;
case '=':
*lexemePtr = GEQ;
return 2;
}
}
*lexemePtr = GREATER;
return 1;
case 'i':
if ((numBytes > 1) && (start[1] == 'n')
&& ((numBytes == 2) || !isalpha(UCHAR(start[2])))) {
/*
* Must make this check so we can tell the difference between
* the "in" operator and the "int" function name and the
* "infinity" numeric value.
*/
*lexemePtr = IN_LIST;
return 2;
}
break;
case 'e':
if ((numBytes > 1) && (start[1] == 'q')
&& ((numBytes == 2) || !isalpha(UCHAR(start[2])))) {
*lexemePtr = STREQ;
return 2;
}
break;
case 'n':
if ((numBytes > 1) && ((numBytes == 2) || !isalpha(UCHAR(start[2])))) {
switch (start[1]) {
case 'e':
*lexemePtr = STRNEQ;
return 2;
case 'i':
*lexemePtr = NOT_IN_LIST;
return 2;
}
}
}
literal = Tcl_NewObj();
if (TclParseNumber(NULL, literal, NULL, start, numBytes, &end,
TCL_PARSE_NO_WHITESPACE) == TCL_OK) {
TclInitStringRep(literal, start, end-start);
*lexemePtr = NUMBER;
if (literalPtr) {
*literalPtr = literal;
} else {
Tcl_DecrRefCount(literal);
}
return (end-start);
}
if (Tcl_UtfCharComplete(start, numBytes)) {
scanned = Tcl_UtfToUniChar(start, &ch);
} else {
char utfBytes[TCL_UTF_MAX];
memcpy(utfBytes, start, (size_t) numBytes);
utfBytes[numBytes] = '\0';
scanned = Tcl_UtfToUniChar(utfBytes, &ch);
}
if (!isalpha(UCHAR(ch))) {
*lexemePtr = INVALID;
Tcl_DecrRefCount(literal);
return scanned;
}
end = start;
while (isalnum(UCHAR(ch)) || (UCHAR(ch) == '_')) {
end += scanned;
numBytes -= scanned;
if (Tcl_UtfCharComplete(end, numBytes)) {
scanned = Tcl_UtfToUniChar(end, &ch);
} else {
char utfBytes[TCL_UTF_MAX];
memcpy(utfBytes, end, (size_t) numBytes);
utfBytes[numBytes] = '\0';
scanned = Tcl_UtfToUniChar(utfBytes, &ch);
}
}
*lexemePtr = BAREWORD;
if (literalPtr) {
Tcl_SetStringObj(literal, start, (int) (end-start));
*literalPtr = literal;
} else {
Tcl_DecrRefCount(literal);
}
return (end-start);
}
/*
*----------------------------------------------------------------------
*
* TclCompileExpr --
*
* This procedure compiles a string containing a Tcl expression into Tcl
* bytecodes. This procedure is the top-level interface to the the
* expression compilation module, and is used by such public procedures
* as Tcl_ExprString, Tcl_ExprStringObj, Tcl_ExprLong, Tcl_ExprDouble,
* Tcl_ExprBoolean, and Tcl_ExprBooleanObj.
*
* Results:
* The return value is TCL_OK on a successful compilation and TCL_ERROR
* on failure. If TCL_ERROR is returned, then the interpreter's result
* contains an error message.
*
* Side effects:
* Adds instructions to envPtr to evaluate the expression at runtime.
*
*----------------------------------------------------------------------
*/
int
TclCompileExpr(
Tcl_Interp *interp, /* Used for error reporting. */
const char *script, /* The source script to compile. */
int numBytes, /* Number of bytes in script. */
CompileEnv *envPtr) /* Holds resulting instructions. */
{
OpNode *opTree = NULL; /* Will point to the tree of operators */
Tcl_Obj *litList = Tcl_NewObj(); /* List to hold the literals */
Tcl_Obj *funcList = Tcl_NewObj(); /* List to hold the functon names*/
Tcl_Parse *parsePtr =
(Tcl_Parse *) TclStackAlloc(interp, sizeof(Tcl_Parse));
/* Holds the Tcl_Tokens of substitutions */
int code = ParseExpr(interp, script, numBytes, &opTree, litList,
funcList, parsePtr, 0 /* parseOnly */);
if (code == TCL_OK) {
int litObjc, needsNumConversion = 1;
Tcl_Obj **litObjv;
/* TIP #280 : Track Lines within the expression */
TclAdvanceLines(&envPtr->line, script,
script + TclParseAllWhiteSpace(script, numBytes));
/*
* Valid parse; compile the tree.
*/
Tcl_ListObjGetElements(NULL, litList, &litObjc, &litObjv);
CompileExprTree(interp, opTree, litObjv, funcList, parsePtr->tokenPtr,
&needsNumConversion, envPtr);
if (needsNumConversion) {
/*
* Attempt to convert the expression result to an int or double.
* This is done in order to support Tcl's policy of interpreting
* operands if at all possible as first integers, else
* floating-point numbers.
*/
TclEmitOpcode(INST_TRY_CVT_TO_NUMERIC, envPtr);
}
}
Tcl_FreeParse(parsePtr);
TclStackFree(interp, parsePtr);
Tcl_DecrRefCount(funcList);
Tcl_DecrRefCount(litList);
ckfree((char *) opTree);
return code;
}
/*
*----------------------------------------------------------------------
*
* CompileExprTree --
* [???]
*
* Results:
* None.
*
* Side effects:
* Adds instructions to envPtr to evaluate the expression at runtime.
*
*----------------------------------------------------------------------
*/
static void
CompileExprTree(
Tcl_Interp *interp,
OpNode *nodes,
Tcl_Obj *const litObjv[],
Tcl_Obj *funcList,
Tcl_Token *tokenPtr,
int *convertPtr,
CompileEnv *envPtr)
{
OpNode *nodePtr = nodes;
int nextFunc = 0;
JumpList *freePtr, *jumpPtr = NULL;
static const int instruction[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, INST_ADD, INST_SUB, 0, /* COMMA */
INST_MULT, INST_DIV, INST_MOD, INST_LT,
INST_GT, INST_BITAND, INST_BITXOR, INST_BITOR,
0, /* QUESTION */ 0, /* COLON */
INST_LSHIFT, INST_RSHIFT, INST_LE, INST_GE,
INST_EQ, INST_NEQ, 0, /* AND */ 0, /* OR */
INST_STR_EQ, INST_STR_NEQ, INST_EXPON, INST_LIST_IN,
INST_LIST_NOT_IN, 0, /* CLOSE_PAREN */ 0, /* END */
0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, INST_UPLUS, INST_UMINUS, 0, /* FUNCTION */
0, /* START */ 0, /* OPEN_PAREN */
INST_LNOT, INST_BITNOT
};
while (1) {
switch (NODE_TYPE & nodePtr->lexeme) {
case UNARY:
if (nodePtr->right > OT_NONE) {
int right = nodePtr->right;
nodePtr->right = OT_NONE;
if (nodePtr->lexeme == FUNCTION) {
Tcl_DString cmdName;
Tcl_Obj *funcName;
const char *p;
int length;
Tcl_DStringInit(&cmdName);
Tcl_DStringAppend(&cmdName, "tcl::mathfunc::", -1);
Tcl_ListObjIndex(NULL, funcList, nextFunc++, &funcName);
p = Tcl_GetStringFromObj(funcName, &length);
Tcl_DStringAppend(&cmdName, p, length);
TclEmitPush(TclRegisterNewNSLiteral(envPtr,
Tcl_DStringValue(&cmdName),
Tcl_DStringLength(&cmdName)), envPtr);
Tcl_DStringFree(&cmdName);
}
switch (right) {
case OT_EMPTY:
break;
case OT_LITERAL:
/* TODO: reduce constant expressions */
TclEmitPush( TclAddLiteralObj(
envPtr, *litObjv++, NULL), envPtr);
break;
case OT_TOKENS:
if (tokenPtr->type != TCL_TOKEN_WORD) {
Tcl_Panic("unexpected token type %d\n",
tokenPtr->type);
}
TclCompileTokens(interp, tokenPtr+1,
tokenPtr->numComponents, envPtr);
tokenPtr += tokenPtr->numComponents + 1;
break;
default:
nodePtr = nodes + right;
}
} else {
if (nodePtr->lexeme == START) {
/* We're done */
return;
}
if (nodePtr->lexeme == OPEN_PAREN) {
/* do nothing */
} else if (nodePtr->lexeme == FUNCTION) {
int numWords = (nodePtr[1].left - OT_NONE) + 1;
if (numWords < 255) {
TclEmitInstInt1(INST_INVOKE_STK1, numWords, envPtr);
} else {
TclEmitInstInt4(INST_INVOKE_STK4, numWords, envPtr);
}
*convertPtr = 1;
} else {
TclEmitOpcode(instruction[nodePtr->lexeme], envPtr);
*convertPtr = 0;
}
nodePtr = nodes + nodePtr->p.parent;
}
break;
case BINARY:
if (nodePtr->left > OT_NONE) {
int left = nodePtr->left;
nodePtr->left = OT_NONE;
/* TODO: reduce constant expressions */
if (nodePtr->lexeme == QUESTION) {
JumpList *newJump = (JumpList *)
TclStackAlloc(interp, sizeof(JumpList));
newJump->next = jumpPtr;
jumpPtr = newJump;
newJump = (JumpList *)
TclStackAlloc(interp, sizeof(JumpList));
newJump->next = jumpPtr;
jumpPtr = newJump;
jumpPtr->depth = envPtr->currStackDepth;
*convertPtr = 1;
} else if (nodePtr->lexeme == AND || nodePtr->lexeme == OR) {
JumpList *newJump = (JumpList *)
TclStackAlloc(interp, sizeof(JumpList));
newJump->next = jumpPtr;
jumpPtr = newJump;
newJump = (JumpList *)
TclStackAlloc(interp, sizeof(JumpList));
newJump->next = jumpPtr;
jumpPtr = newJump;
newJump = (JumpList *)
TclStackAlloc(interp, sizeof(JumpList));
newJump->next = jumpPtr;
jumpPtr = newJump;
jumpPtr->depth = envPtr->currStackDepth;
}
switch (left) {
case OT_LITERAL:
TclEmitPush(TclAddLiteralObj(envPtr, *litObjv++, NULL),
envPtr);
break;
case OT_TOKENS:
if (tokenPtr->type != TCL_TOKEN_WORD) {
Tcl_Panic("unexpected token type %d\n",
tokenPtr->type);
}
TclCompileTokens(interp, tokenPtr+1,
tokenPtr->numComponents, envPtr);
tokenPtr += tokenPtr->numComponents + 1;
break;
default:
nodePtr = nodes + left;
}
} else if (nodePtr->right > OT_NONE) {
int right = nodePtr->right;
nodePtr->right = OT_NONE;
if (nodePtr->lexeme == QUESTION) {
TclEmitForwardJump(envPtr, TCL_FALSE_JUMP,
&(jumpPtr->jump));
} else if (nodePtr->lexeme == COLON) {
TclEmitForwardJump(envPtr, TCL_UNCONDITIONAL_JUMP,
&(jumpPtr->next->jump));
envPtr->currStackDepth = jumpPtr->depth;
jumpPtr->offset = (envPtr->codeNext - envPtr->codeStart);
jumpPtr->convert = *convertPtr;
*convertPtr = 1;
} else if (nodePtr->lexeme == AND) {
TclEmitForwardJump(envPtr, TCL_FALSE_JUMP,
&(jumpPtr->jump));
} else if (nodePtr->lexeme == OR) {
TclEmitForwardJump(envPtr, TCL_TRUE_JUMP,
&(jumpPtr->jump));
}
switch (right) {
case OT_LITERAL:
TclEmitPush(TclAddLiteralObj(envPtr, *litObjv++, NULL),
envPtr);
break;
case OT_TOKENS:
if (tokenPtr->type != TCL_TOKEN_WORD) {
Tcl_Panic("unexpected token type %d\n",
tokenPtr->type);
}
TclCompileTokens(interp, tokenPtr+1,
tokenPtr->numComponents, envPtr);
tokenPtr += tokenPtr->numComponents + 1;
break;
default:
nodePtr = nodes + right;
}
} else {
if (nodePtr->lexeme == COMMA || nodePtr->lexeme == QUESTION) {
/* do nothing */
} else if (nodePtr->lexeme == COLON) {
if (TclFixupForwardJump(envPtr, &(jumpPtr->next->jump),
(envPtr->codeNext - envPtr->codeStart)
- jumpPtr->next->jump.codeOffset, 127)) {
jumpPtr->offset += 3;
}
TclFixupForwardJump(envPtr, &(jumpPtr->jump),
jumpPtr->offset - jumpPtr->jump.codeOffset, 127);
*convertPtr |= jumpPtr->convert;
envPtr->currStackDepth = jumpPtr->depth + 1;
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
} else if (nodePtr->lexeme == AND) {
TclEmitForwardJump(envPtr, TCL_FALSE_JUMP,
&(jumpPtr->next->jump));
TclEmitPush(TclRegisterNewLiteral(envPtr, "1", 1), envPtr);
} else if (nodePtr->lexeme == OR) {
TclEmitForwardJump(envPtr, TCL_TRUE_JUMP,
&(jumpPtr->next->jump));
TclEmitPush(TclRegisterNewLiteral(envPtr, "0", 1), envPtr);
} else {
TclEmitOpcode(instruction[nodePtr->lexeme], envPtr);
*convertPtr = 0;
}
if ((nodePtr->lexeme == AND) || (nodePtr->lexeme == OR)) {
TclEmitForwardJump(envPtr, TCL_UNCONDITIONAL_JUMP,
&(jumpPtr->next->next->jump));
TclFixupForwardJumpToHere(envPtr,
&(jumpPtr->next->jump), 127);
if (TclFixupForwardJumpToHere(envPtr,
&(jumpPtr->jump), 127)) {
jumpPtr->next->next->jump.codeOffset += 3;
}
TclEmitPush(TclRegisterNewLiteral(envPtr,
(nodePtr->lexeme == AND) ? "0" : "1", 1), envPtr);
TclFixupForwardJumpToHere(envPtr,
&(jumpPtr->next->next->jump), 127);
*convertPtr = 0;
envPtr->currStackDepth = jumpPtr->depth + 1;
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
}
nodePtr = nodes + nodePtr->p.parent;
}
break;
}
}
}
static int
OpCmd(
Tcl_Interp *interp,
OpNode *nodes,
Tcl_Obj * const litObjv[])
{
CompileEnv *compEnvPtr;
ByteCode *byteCodePtr;
int code, tmp=1;
Tcl_Obj *byteCodeObj = Tcl_NewObj();
/*
* Note we are compiling an expression with literal arguments. This means
* there can be no [info frame] calls when we execute the resulting
* bytecode, so there's no need to tend to TIP 280 issues.
*/
compEnvPtr = (CompileEnv *) TclStackAlloc(interp, sizeof(CompileEnv));
TclInitCompileEnv(interp, compEnvPtr, NULL, 0, NULL, 0);
CompileExprTree(interp, nodes, litObjv, NULL, NULL, &tmp, compEnvPtr);
TclEmitOpcode(INST_DONE, compEnvPtr);
Tcl_IncrRefCount(byteCodeObj);
TclInitByteCodeObj(byteCodeObj, compEnvPtr);
TclFreeCompileEnv(compEnvPtr);
TclStackFree(interp, compEnvPtr);
byteCodePtr = (ByteCode *) byteCodeObj->internalRep.otherValuePtr;
code = TclExecuteByteCode(interp, byteCodePtr);
Tcl_DecrRefCount(byteCodeObj);
return code;
}
int
TclSingleOpCmd(
ClientData clientData,
Tcl_Interp *interp,
int objc,
Tcl_Obj *const objv[])
{
TclOpCmdClientData *occdPtr = (TclOpCmdClientData *)clientData;
unsigned char lexeme;
OpNode nodes[2];
if (objc != 1+occdPtr->numArgs) {
Tcl_WrongNumArgs(interp, 1, objv, occdPtr->expected);
return TCL_ERROR;
}
ParseLexeme(occdPtr->operator, strlen(occdPtr->operator), &lexeme, NULL);
nodes[0].lexeme = START;
nodes[0].right = 1;
nodes[1].lexeme = lexeme;
nodes[1].left = OT_LITERAL;
nodes[1].right = OT_LITERAL;
nodes[1].p.parent = 0;
return OpCmd(interp, nodes, objv+1);
}
int
TclSortingOpCmd(
ClientData clientData,
Tcl_Interp *interp,
int objc,
Tcl_Obj *const objv[])
{
int code = TCL_OK;
if (objc < 3) {
Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
} else {
TclOpCmdClientData *occdPtr = (TclOpCmdClientData *)clientData;
Tcl_Obj **litObjv = (Tcl_Obj **) TclStackAlloc(interp,
2*(objc-2)*sizeof(Tcl_Obj *));
OpNode *nodes = (OpNode *) TclStackAlloc(interp,
2*(objc-2)*sizeof(OpNode));
unsigned char lexeme;
int i, lastAnd = 1;
ParseLexeme(occdPtr->operator, strlen(occdPtr->operator),
&lexeme, NULL);
litObjv[0] = objv[1];
nodes[0].lexeme = START;
for (i=2; i<objc-1; i++) {
litObjv[2*(i-1)-1] = objv[i];
nodes[2*(i-1)-1].lexeme = lexeme;
nodes[2*(i-1)-1].left = OT_LITERAL;
nodes[2*(i-1)-1].right = OT_LITERAL;
litObjv[2*(i-1)] = objv[i];
nodes[2*(i-1)].lexeme = AND;
nodes[2*(i-1)].left = lastAnd;
nodes[lastAnd].p.parent = 2*(i-1);
nodes[2*(i-1)].right = 2*(i-1)+1;
nodes[2*(i-1)+1].p.parent= 2*(i-1);
lastAnd = 2*(i-1);
}
litObjv[2*(objc-2)-1] = objv[objc-1];
nodes[2*(objc-2)-1].lexeme = lexeme;
nodes[2*(objc-2)-1].left = OT_LITERAL;
nodes[2*(objc-2)-1].right = OT_LITERAL;
nodes[0].right = lastAnd;
nodes[lastAnd].p.parent = 0;
code = OpCmd(interp, nodes, litObjv);
TclStackFree(interp, nodes);
TclStackFree(interp, litObjv);
}
return code;
}
int
TclVariadicOpCmd(
ClientData clientData,
Tcl_Interp *interp,
int objc,
Tcl_Obj *const objv[])
{
TclOpCmdClientData *occdPtr = (TclOpCmdClientData *)clientData;
unsigned char lexeme;
int code;
if (objc < 2) {
Tcl_SetObjResult(interp, Tcl_NewIntObj(occdPtr->numArgs));
return TCL_OK;
}
ParseLexeme(occdPtr->operator, strlen(occdPtr->operator), &lexeme, NULL);
lexeme |= BINARY;
if (objc == 2) {
Tcl_Obj *litObjv[2];
OpNode nodes[2];
int decrMe = 0;
if (lexeme == EXPON) {
litObjv[1] = Tcl_NewIntObj(occdPtr->numArgs);
Tcl_IncrRefCount(litObjv[1]);
decrMe = 1;
litObjv[0] = objv[1];
nodes[0].lexeme = START;
nodes[0].right = 1;
nodes[1].lexeme = lexeme;
nodes[1].left = OT_LITERAL;
nodes[1].right = OT_LITERAL;
nodes[1].p.parent = 0;
} else {
if (lexeme == DIVIDE) {
litObjv[0] = Tcl_NewDoubleObj(1.0);
} else {
litObjv[0] = Tcl_NewIntObj(occdPtr->numArgs);
}
Tcl_IncrRefCount(litObjv[0]);
litObjv[1] = objv[1];
nodes[0].lexeme = START;
nodes[0].right = 1;
nodes[1].lexeme = lexeme;
nodes[1].left = OT_LITERAL;
nodes[1].right = OT_LITERAL;
nodes[1].p.parent = 0;
}
code = OpCmd(interp, nodes, litObjv);
Tcl_DecrRefCount(litObjv[decrMe]);
return code;
} else {
OpNode *nodes = (OpNode *) TclStackAlloc(interp,
(objc-1)*sizeof(OpNode));
int i, lastOp = OT_LITERAL;
nodes[0].lexeme = START;
if (lexeme == EXPON) {
for (i=objc-2; i>0; i-- ) {
nodes[i].lexeme = lexeme;
nodes[i].left = OT_LITERAL;
nodes[i].right = lastOp;
if (lastOp >= 0) {
nodes[lastOp].p.parent = i;
}
lastOp = i;
}
} else {
for (i=1; i<objc-1; i++ ) {
nodes[i].lexeme = lexeme;
nodes[i].left = lastOp;
if (lastOp >= 0) {
nodes[lastOp].p.parent = i;
}
nodes[i].right = OT_LITERAL;
lastOp = i;
}
}
nodes[0].right = lastOp;
nodes[lastOp].p.parent = 0;
code = OpCmd(interp, nodes, objv+1);
TclStackFree(interp, nodes);
return code;
}
}
int
TclNoIdentOpCmd(
ClientData clientData,
Tcl_Interp *interp,
int objc,
Tcl_Obj *const objv[])
{
TclOpCmdClientData *occdPtr = (TclOpCmdClientData *)clientData;
if (objc < 2) {
Tcl_WrongNumArgs(interp, 1, objv, occdPtr->expected);
return TCL_ERROR;
}
return TclVariadicOpCmd(clientData, interp, objc, objv);
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/