/*
* 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::+ .
*
* Contributions from Don Porter, NIST, 2006-2007. (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 1.97.2.1 2010/01/06 21:35:25 nijtmans 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 */
unsigned char mark; /* Mark used to control traversal. */
unsigned char constant; /* Flag marking constant subexpressions. */
} 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_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 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 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.
*
* The precedence field provides a place to store the precedence of the
* operator, so it need not be looked up again and again.
*
* The mark field is use to control the traversal of the tree, so
* that it can be done non-recursively. The mark values are:
*/
enum Marks {
MARK_LEFT, /* Next step of traversal is to visit left subtree */
MARK_RIGHT, /* Next step of traversal is to visit right subtree */
MARK_PARENT /* Next step of traversal is to return to parent */
};
/*
* The constant field is a boolean flag marking which subexpressions are
* completely known at compile time, and are eligible for computing then
* rather than waiting until run time.
*/
/*
* 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*/
};
/*
* A table mapping lexemes to bytecode instructions, used by CompileExprTree().
*/
static const unsigned char instruction[] = {
/* 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 */
INST_ADD, /* BINARY_PLUS */
INST_SUB, /* BINARY_MINUS */
0, /* COMMA */
INST_MULT, /* MULT */
INST_DIV, /* DIVIDE */
INST_MOD, /* MOD */
INST_LT, /* LESS */
INST_GT, /* GREATER */
INST_BITAND, /* BIT_AND */
INST_BITXOR, /* BIT_XOR */
INST_BITOR, /* BIT_OR */
0, /* QUESTION */
0, /* COLON */
INST_LSHIFT, /* LEFT_SHIFT */
INST_RSHIFT, /* RIGHT_SHIFT */
INST_LE, /* LEQ */
INST_GE, /* GEQ */
INST_EQ, /* EQUAL */
INST_NEQ, /* NEQ */
0, /* AND */
0, /* OR */
INST_STR_EQ, /* STREQ */
INST_STR_NEQ, /* STRNEQ */
INST_EXPON, /* EXPON */
INST_LIST_IN, /* IN_LIST */
INST_LIST_NOT_IN, /* NOT_IN_LIST */
0, /* CLOSE_PAREN */
0, /* 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 */
INST_UPLUS, /* UNARY_PLUS */
INST_UMINUS, /* UNARY_MINUS */
0, /* FUNCTION */
0, /* START */
0, /* OPEN_PAREN */
INST_LNOT, /* NOT*/
INST_BITNOT, /* BIT_NOT*/
};
/*
* A table mapping a byte value to the corresponding lexeme for use by
* ParseLexeme().
*/
static unsigned char Lexeme[] = {
INVALID /* NUL */, INVALID /* SOH */,
INVALID /* STX */, INVALID /* ETX */,
INVALID /* EOT */, INVALID /* ENQ */,
INVALID /* ACK */, INVALID /* BEL */,
INVALID /* BS */, INVALID /* HT */,
INVALID /* LF */, INVALID /* VT */,
INVALID /* FF */, INVALID /* CR */,
INVALID /* SO */, INVALID /* SI */,
INVALID /* DLE */, INVALID /* DC1 */,
INVALID /* DC2 */, INVALID /* DC3 */,
INVALID /* DC4 */, INVALID /* NAK */,
INVALID /* SYN */, INVALID /* ETB */,
INVALID /* CAN */, INVALID /* EM */,
INVALID /* SUB */, INVALID /* ESC */,
INVALID /* FS */, INVALID /* GS */,
INVALID /* RS */, INVALID /* US */,
INVALID /* SPACE */, 0 /* ! or != */,
QUOTED /* " */, INVALID /* # */,
VARIABLE /* $ */, MOD /* % */,
0 /* & or && */, INVALID /* ' */,
OPEN_PAREN /* ( */, CLOSE_PAREN /* ) */,
0 /* * or ** */, PLUS /* + */,
COMMA /* , */, MINUS /* - */,
0 /* . */, DIVIDE /* / */,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0-9 */
COLON /* : */, INVALID /* ; */,
0 /* < or << or <= */,
0 /* == or INVALID */,
0 /* > or >> or >= */,
QUESTION /* ? */, INVALID /* @ */,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* A-M */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* N-Z */
SCRIPT /* [ */, INVALID /* \ */,
INVALID /* ] */, BIT_XOR /* ^ */,
INVALID /* _ */, INVALID /* ` */,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* a-m */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* n-z */
BRACED /* { */, 0 /* | or || */,
INVALID /* } */, BIT_NOT /* ~ */,
INVALID /* DEL */
};
/*
* 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,
int index, Tcl_Obj *const **litObjvPtr,
Tcl_Obj *const *funcObjv, Tcl_Token *tokenPtr,
CompileEnv *envPtr, int optimize);
static void ConvertTreeToTokens(const char *start, int numBytes,
OpNode *nodes, Tcl_Token *tokenPtr,
Tcl_Parse *parsePtr);
static int ExecConstantExprTree(Tcl_Interp *interp, OpNode *nodes,
int index, Tcl_Obj * const **litObjvPtr);
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_EMPTY; /* "Index" of the complete tree (that is, a
* complete subexpression) determined at the
* moment. OT_EMPTY 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->mark = MARK_RIGHT;
nodes->constant = 1;
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) ? "" : "...");
if (NotOperator(lastParsed)) {
if ((lastStart[0] == '0')
&& ((lastStart[1] == 'o')
|| (lastStart[1] == 'O'))
&& (lastStart[2] >= '0')
&& (lastStart[2] <= '9')) {
const char *end = lastStart + 2;
Tcl_Obj* copy;
while (isdigit(UCHAR(*end))) {
end++;
}
copy = Tcl_NewStringObj(lastStart,
end - lastStart);
if (TclCheckBadOctal(NULL,
Tcl_GetString(copy))) {
Tcl_AppendToObj(post,
"(invalid octal number?)", -1);
}
Tcl_DecrRefCount(copy);
}
scanned = 0;
insertMark = 1;
parsePtr->errorType = TCL_PARSE_BAD_NUMBER;
}
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:
/*
* TODO: Consider using a dict or hash to collapse all
* duplicate literals into a single representative value.
* (Like what is done with [split $s {}]).
* Pro: ~75% memory saving on expressions like
* {1+1+1+1+1+.....+1} (Convert "pointer + Tcl_Obj" cost
* to "pointer" cost only)
* Con: Cost of the dict store/retrieve on every literal
* in every expression when expressions like the above
* tend to be uncommon.
* The memory savings is temporary; Compiling to bytecode
* will collapse things as literals are registered
* anyway, so the savings applies only to the time
* between parsing and compiling. Possibly important
* due to high-water mark nature of memory allocation.
*/
Tcl_ListObjAppendElement(NULL, litList, literal);
complete = lastParsed = OT_LITERAL;
start += scanned;
numBytes -= scanned;
continue;
default:
break;
}
/*
* Remaining LEAF cases may involve filling Tcl_Tokens, so
* make room for at least 2 more tokens.
*/
TclGrowParseTokenArray(parsePtr, 2);
wordIndex = parsePtr->numTokens;
tokenPtr = parsePtr->tokenPtr + wordIndex;
tokenPtr->type = TCL_TOKEN_WORD;
tokenPtr->start = start;
parsePtr->numTokens++;
switch (lexeme) {
case QUOTED:
code = Tcl_ParseQuotedString(NULL, start, numBytes,
parsePtr, 1, &end);
scanned = end - start;
break;
case BRACED:
code = Tcl_ParseBraces(NULL, start, numBytes,
parsePtr, 1, &end);
scanned = end - start;
break;
case VARIABLE:
code = Tcl_ParseVarName(NULL, start, numBytes, parsePtr, 1);
/*
* Handle the quirk that Tcl_ParseVarName reports a successful
* parse even when it gets only a "$" 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;
nodePtr->precedence = prec[lexeme];
nodePtr->mark = MARK_RIGHT;
/*
* A FUNCTION cannot be a constant expression, because Tcl allows
* functions to return variable results with the same arguments;
* for example, rand(). Other unary operators can root a constant
* expression, so long as the argument is a constant expression.
*/
nodePtr->constant = (lexeme != FUNCTION);
/*
* 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;
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;
incompletePtr->constant = incompletePtr->constant
&& nodes[complete].constant;
} else {
incompletePtr->constant = incompletePtr->constant
&& (complete == OT_LITERAL);
}
/*
* The QUESTION/COLON and FUNCTION/OPEN_PAREN combinations each
* make up a single operator. Force them to agree whether they
* have a constant expression.
*/
if ((incompletePtr->lexeme == QUESTION)
|| (incompletePtr->lexeme == FUNCTION)) {
nodes[complete].constant = incompletePtr->constant;
}
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;
}
}
/* 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) {
break;
}
/* Link complete tree as left operand of new node. */
nodePtr->lexeme = lexeme;
nodePtr->precedence = precedence;
nodePtr->mark = MARK_LEFT;
nodePtr->left = complete;
/*
* The COMMA operator cannot be optimized, since the function
* needs all of its arguments, and optimization would reduce
* the number. Other binary operators root constant expressions
* when both arguments are constant expressions.
*/
nodePtr->constant = (lexeme != COMMA);
if (IsOperator(complete)) {
nodes[complete].p.parent = nodesUsed;
nodePtr->constant = nodePtr->constant
&& nodes[complete].constant;
} else {
nodePtr->constant = nodePtr->constant
&& (complete == OT_LITERAL);
}
/*
* 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;
}
/*
*----------------------------------------------------------------------
*
* ConvertTreeToTokens --
*
* Given a string, the numBytes bytes starting at start, and an OpNode
* tree and Tcl_Token array created by passing that same string to
* ParseExpr(), this function writes into *parsePtr the sequence of
* Tcl_Tokens needed so to satisfy the historical interface provided
* by Tcl_ParseExpr(). Note that this routine exists only for the sake
* of the public Tcl_ParseExpr() routine. It is not used by Tcl itself
* at all.
*
* 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)
{
int subExprTokenIdx = 0;
OpNode *nodePtr = nodes;
int next = nodePtr->right;
while (1) {
Tcl_Token *subExprTokenPtr;
int scanned, parentIdx;
unsigned char lexeme;
/*
* Advance the mark so the next exit from this node won't retrace
* steps over ground already covered.
*/
nodePtr->mark++;
/* Handle next child node or leaf */
switch (next) {
case OT_EMPTY:
/* No tokens and no characters for the OT_EMPTY leaf. */
break;
case OT_LITERAL:
/* Skip any white space that comes before the literal */
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
/* Reparse the literal to get pointers into source string */
scanned = ParseLexeme(start, numBytes, &lexeme, NULL);
TclGrowParseTokenArray(parsePtr, 2);
subExprTokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
subExprTokenPtr->start = start;
subExprTokenPtr->size = scanned;
subExprTokenPtr->numComponents = 1;
subExprTokenPtr[1].type = TCL_TOKEN_TEXT;
subExprTokenPtr[1].start = start;
subExprTokenPtr[1].size = scanned;
subExprTokenPtr[1].numComponents = 0;
parsePtr->numTokens += 2;
start +=scanned;
numBytes -= scanned;
break;
case OT_TOKENS: {
/*
* tokenPtr points to a token sequence that came from parsing
* a Tcl word. A Tcl word is made up of a sequence of one or
* more elements. When the word is only a single element, it's
* been the historical practice to replace the TCL_TOKEN_WORD
* token directly with a TCL_TOKEN_SUB_EXPR token. However,
* when the word has multiple elements, a TCL_TOKEN_WORD token
* is kept as a grouping device so that TCL_TOKEN_SUB_EXPR
* always has only one element. Wise or not, these are the
* rules the Tcl expr parser has followed, and for the sake
* of those few callers of Tcl_ParseExpr() we do not change
* them now. Internally, we can do better.
*/
int toCopy = tokenPtr->numComponents + 1;
if (tokenPtr->numComponents == tokenPtr[1].numComponents + 1) {
/*
* Single element word. Copy tokens and convert the leading
* token to TCL_TOKEN_SUB_EXPR.
*/
TclGrowParseTokenArray(parsePtr, toCopy);
subExprTokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
memcpy(subExprTokenPtr, tokenPtr,
(size_t) toCopy * sizeof(Tcl_Token));
subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
parsePtr->numTokens += toCopy;
} else {
/*
* Multiple element word. Create a TCL_TOKEN_SUB_EXPR
* token to lead, with fields initialized from the leading
* token, then copy entire set of word tokens.
*/
TclGrowParseTokenArray(parsePtr, toCopy+1);
subExprTokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
*subExprTokenPtr = *tokenPtr;
subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
subExprTokenPtr->numComponents++;
subExprTokenPtr++;
memcpy(subExprTokenPtr, tokenPtr,
(size_t) toCopy * sizeof(Tcl_Token));
parsePtr->numTokens += toCopy + 1;
}
scanned = tokenPtr->start + tokenPtr->size - start;
start +=scanned;
numBytes -= scanned;
tokenPtr += toCopy;
break;
}
default:
/* Advance to the child node, which is an operator. */
nodePtr = nodes + next;
/* Skip any white space that comes before the subexpression */
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
/* Generate tokens for the operator / subexpression... */
switch (nodePtr->lexeme) {
case OPEN_PAREN:
case COMMA:
case COLON:
/*
* Historical practice has been to have no Tcl_Tokens for
* these operators.
*/
break;
default: {
/*
* Remember the index of the last subexpression we were
* working on -- that of our parent. We'll stack it later.
*/
parentIdx = subExprTokenIdx;
/*
* Verify space for the two leading Tcl_Tokens representing
* the subexpression rooted by this operator. The first
* Tcl_Token will be of type TCL_TOKEN_SUB_EXPR; the second
* of type TCL_TOKEN_OPERATOR.
*/
TclGrowParseTokenArray(parsePtr, 2);
subExprTokenIdx = parsePtr->numTokens;
subExprTokenPtr = parsePtr->tokenPtr + subExprTokenIdx;
parsePtr->numTokens += 2;
subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
subExprTokenPtr[1].type = TCL_TOKEN_OPERATOR;
/*
* Our current position scanning the string is the starting
* point for this subexpression.
*/
subExprTokenPtr->start = start;
/*
* Eventually, we know that the numComponents field of the
* Tcl_Token of type TCL_TOKEN_OPERATOR will be 0. This means
* we can make other use of this field for now to track the
* stack of subexpressions we have pending.
*/
subExprTokenPtr[1].numComponents = parentIdx;
break;
}
}
break;
}
/* Determine which way to exit the node on this pass. */
router:
switch (nodePtr->mark) {
case MARK_LEFT:
next = nodePtr->left;
break;
case MARK_RIGHT:
next = nodePtr->right;
/* Skip any white space that comes before the operator */
scanned = TclParseAllWhiteSpace(start, numBytes);
start +=scanned;
numBytes -= scanned;
/*
* Here we scan from the string the operator corresponding to
* nodePtr->lexeme.
*/
scanned = ParseLexeme(start, numBytes, &lexeme, NULL);
switch(nodePtr->lexeme) {
case OPEN_PAREN:
case COMMA:
case COLON:
/* No tokens for these lexemes -> nothing to do. */
break;
default:
/*
* Record in the TCL_TOKEN_OPERATOR token the pointers into
* the string marking where the operator is.
*/
subExprTokenPtr = parsePtr->tokenPtr + subExprTokenIdx;
subExprTokenPtr[1].start = start;
subExprTokenPtr[1].size = scanned;
break;
}
start +=scanned;
numBytes -= scanned;
break;
case MARK_PARENT:
switch (nodePtr->lexeme) {
case START:
/* When we get back to the START node, we're done. */
return;
case COMMA:
case COLON:
/* No tokens for these lexemes -> nothing to do. */
break;
case 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;
break;
default: {
/*
* Before we leave this node/operator/subexpression for the
* last time, finish up its tokens....
*
* Our current position scanning the string is where the
* substring for the subexpression ends.
*/
subExprTokenPtr = parsePtr->tokenPtr + subExprTokenIdx;
subExprTokenPtr->size = start - subExprTokenPtr->start;
/*
* All the Tcl_Tokens allocated and filled belong to
* this subexpresion. The first token is the leading
* TCL_TOKEN_SUB_EXPR token, and all the rest (one fewer)
* are its components.
*/
subExprTokenPtr->numComponents =
(parsePtr->numTokens - subExprTokenIdx) - 1;
/*
* Finally, as we return up the tree to our parent, pop the
* parent subexpression off our subexpression stack, and
* fill in the zero numComponents for the operator Tcl_Token.
*/
parentIdx = subExprTokenPtr[1].numComponents;
subExprTokenPtr[1].numComponents = 0;
subExprTokenIdx = parentIdx;
break;
}
}
/* Since we're returning to parent, skip child handling code. */
nodePtr = nodes + nodePtr->p.parent;
goto router;
}
}
}
/*
*----------------------------------------------------------------------
*
* 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;
unsigned char byte;
if (numBytes == 0) {
*lexemePtr = END;
return 0;
}
byte = (unsigned char)(*start);
if (byte < sizeof(Lexeme) && Lexeme[byte] != 0) {
*lexemePtr = Lexeme[byte];
return 1;
}
switch (byte) {
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.
*
* Results:
* None.
*
* Side effects:
* Adds instructions to envPtr to evaluate the expression at runtime.
*
*----------------------------------------------------------------------
*/
void
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. */
int optimize) /* 0 for one-off expressions */
{
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) {
/* Valid parse; compile the tree. */
int objc;
Tcl_Obj *const *litObjv;
Tcl_Obj **funcObjv;
/* TIP #280 : Track Lines within the expression */
TclAdvanceLines(&envPtr->line, script,
script + TclParseAllWhiteSpace(script, numBytes));
TclListObjGetElements(NULL, litList, &objc, (Tcl_Obj ***)&litObjv);
TclListObjGetElements(NULL, funcList, &objc, &funcObjv);
CompileExprTree(interp, opTree, 0, &litObjv, funcObjv,
parsePtr->tokenPtr, envPtr, optimize);
} else {
TclCompileSyntaxError(interp, envPtr);
}
Tcl_FreeParse(parsePtr);
TclStackFree(interp, parsePtr);
Tcl_DecrRefCount(funcList);
Tcl_DecrRefCount(litList);
ckfree((char *) opTree);
}
/*
*----------------------------------------------------------------------
*
* ExecConstantExprTree --
* Compiles and executes bytecode for the subexpression tree at index
* in the nodes array. This subexpression must be constant, made up
* of only constant operators (not functions) and literals.
*
* Results:
* A standard Tcl return code and result left in interp.
*
* Side effects:
* Consumes subtree of nodes rooted at index. Advances the pointer
* *litObjvPtr.
*
*----------------------------------------------------------------------
*/
static int
ExecConstantExprTree(
Tcl_Interp *interp,
OpNode *nodes,
int index,
Tcl_Obj *const **litObjvPtr)
{
CompileEnv *envPtr;
ByteCode *byteCodePtr;
int code;
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.
*/
envPtr = (CompileEnv *) TclStackAlloc(interp, sizeof(CompileEnv));
TclInitCompileEnv(interp, envPtr, NULL, 0, NULL, 0);
CompileExprTree(interp, nodes, index, litObjvPtr, NULL, NULL, envPtr,
0 /* optimize */);
TclEmitOpcode(INST_DONE, envPtr);
Tcl_IncrRefCount(byteCodeObj);
TclInitByteCodeObj(byteCodeObj, envPtr);
TclFreeCompileEnv(envPtr);
TclStackFree(interp, envPtr);
byteCodePtr = (ByteCode *) byteCodeObj->internalRep.otherValuePtr;
code = TclExecuteByteCode(interp, byteCodePtr);
Tcl_DecrRefCount(byteCodeObj);
return code;
}
/*
*----------------------------------------------------------------------
*
* CompileExprTree --
* Compiles and writes to envPtr instructions for the subexpression
* tree at index in the nodes array. (*litObjvPtr) must point to the
* proper location in a corresponding literals list. Likewise, when
* non-NULL, funcObjv and tokenPtr must point into matching arrays of
* function names and Tcl_Token's derived from earlier call to
* ParseExpr(). When optimize is true, any constant subexpressions
* will be precomputed.
*
* Results:
* None.
*
* Side effects:
* Adds instructions to envPtr to evaluate the expression at runtime.
* Consumes subtree of nodes rooted at index. Advances the pointer
* *litObjvPtr.
*
*----------------------------------------------------------------------
*/
static void
CompileExprTree(
Tcl_Interp *interp,
OpNode *nodes,
int index,
Tcl_Obj *const **litObjvPtr,
Tcl_Obj *const *funcObjv,
Tcl_Token *tokenPtr,
CompileEnv *envPtr,
int optimize)
{
OpNode *nodePtr = nodes + index;
OpNode *rootPtr = nodePtr;
int numWords = 0;
JumpList *jumpPtr = NULL;
int convert = 1;
while (1) {
int next;
JumpList *freePtr, *newJump;
if (nodePtr->mark == MARK_LEFT) {
next = nodePtr->left;
switch (nodePtr->lexeme) {
case QUESTION:
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;
convert = 1;
break;
case AND:
case OR:
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;
break;
}
} else if (nodePtr->mark == MARK_RIGHT) {
next = nodePtr->right;
switch (nodePtr->lexeme) {
case FUNCTION: {
Tcl_DString cmdName;
const char *p;
int length;
Tcl_DStringInit(&cmdName);
Tcl_DStringAppend(&cmdName, "tcl::mathfunc::", -1);
p = TclGetStringFromObj(*funcObjv, &length);
funcObjv++;
Tcl_DStringAppend(&cmdName, p, length);
TclEmitPush(TclRegisterNewNSLiteral(envPtr,
Tcl_DStringValue(&cmdName),
Tcl_DStringLength(&cmdName)), envPtr);
Tcl_DStringFree(&cmdName);
/*
* Start a count of the number of words in this function
* command invocation. In case there's already a count
* in progress (nested functions), save it in our unused
* "left" field for restoring later.
*/
nodePtr->left = numWords;
numWords = 2; /* Command plus one argument */
break;
}
case QUESTION:
TclEmitForwardJump(envPtr, TCL_FALSE_JUMP, &(jumpPtr->jump));
break;
case COLON:
TclEmitForwardJump(envPtr, TCL_UNCONDITIONAL_JUMP,
&(jumpPtr->next->jump));
envPtr->currStackDepth = jumpPtr->depth;
jumpPtr->offset = (envPtr->codeNext - envPtr->codeStart);
jumpPtr->convert = convert;
convert = 1;
break;
case AND:
TclEmitForwardJump(envPtr, TCL_FALSE_JUMP, &(jumpPtr->jump));
break;
case OR:
TclEmitForwardJump(envPtr, TCL_TRUE_JUMP, &(jumpPtr->jump));
break;
}
} else {
switch (nodePtr->lexeme) {
case START:
case QUESTION:
if (convert && (nodePtr == rootPtr)) {
TclEmitOpcode(INST_TRY_CVT_TO_NUMERIC, envPtr);
}
break;
case OPEN_PAREN:
/* do nothing */
break;
case FUNCTION:
/*
* Use the numWords count we've kept to invoke the
* function command with the correct number of arguments.
*/
if (numWords < 255) {
TclEmitInstInt1(INST_INVOKE_STK1, numWords, envPtr);
} else {
TclEmitInstInt4(INST_INVOKE_STK4, numWords, envPtr);
}
/* Restore any saved numWords value. */
numWords = nodePtr->left;
convert = 1;
break;
case COMMA:
/* Each comma implies another function argument. */
numWords++;
break;
case 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);
convert |= jumpPtr->convert;
envPtr->currStackDepth = jumpPtr->depth + 1;
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
freePtr = jumpPtr;
jumpPtr = jumpPtr->next;
TclStackFree(interp, freePtr);
break;
case AND:
case OR:
TclEmitForwardJump(envPtr, (nodePtr->lexeme == AND)
? TCL_FALSE_JUMP : TCL_TRUE_JUMP,
&(jumpPtr->next->jump));
TclEmitPush(TclRegisterNewLiteral(envPtr,
(nodePtr->lexeme == AND) ? "1" : "0", 1), envPtr);
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);
convert = 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);
break;
default:
TclEmitOpcode(instruction[nodePtr->lexeme], envPtr);
convert = 0;
break;
}
if (nodePtr == rootPtr) {
/* We're done */
return;
}
nodePtr = nodes + nodePtr->p.parent;
continue;
}
nodePtr->mark++;
switch (next) {
case OT_EMPTY:
numWords = 1; /* No arguments, so just the command */
break;
case OT_LITERAL: {
Tcl_Obj *const *litObjv = *litObjvPtr;
Tcl_Obj *literal = *litObjv;
if (optimize) {
int length, index;
const char *bytes = TclGetStringFromObj(literal, &length);
LiteralEntry *lePtr;
Tcl_Obj *objPtr;
index = TclRegisterNewLiteral(envPtr, bytes, length);
lePtr = envPtr->literalArrayPtr + index;
objPtr = lePtr->objPtr;
if ((objPtr->typePtr == NULL) && (literal->typePtr != NULL)) {
/*
* Would like to do this:
*
* lePtr->objPtr = literal;
* Tcl_IncrRefCount(literal);
* Tcl_DecrRefCount(objPtr);
*
* However, the design of the "global" and "local"
* LiteralTable does not permit the value of lePtr->objPtr
* to change. So rather than replace lePtr->objPtr, we
* do surgery to transfer our desired intrep into it.
*
*/
objPtr->typePtr = literal->typePtr;
objPtr->internalRep = literal->internalRep;
literal->typePtr = NULL;
}
TclEmitPush(index, envPtr);
} else {
/*
* When optimize==0, we know the expression is a one-off
* and there's nothing to be gained from sharing literals
* when they won't live long, and the copies we have already
* have an appropriate intrep. In this case, skip literal
* registration that would enable sharing, and use the routine
* that preserves intreps.
*/
TclEmitPush(TclAddLiteralObj(envPtr, literal, NULL), envPtr);
}
(*litObjvPtr)++;
break;
}
case OT_TOKENS:
TclCompileTokens(interp, tokenPtr+1, tokenPtr->numComponents,
envPtr);
tokenPtr += tokenPtr->numComponents + 1;
break;
default:
if (optimize && nodes[next].constant) {
Tcl_InterpState save = Tcl_SaveInterpState(interp, TCL_OK);
if (ExecConstantExprTree(interp, nodes, next, litObjvPtr)
== TCL_OK) {
TclEmitPush(TclAddLiteralObj(envPtr,
Tcl_GetObjResult(interp), NULL), envPtr);
} else {
TclCompileSyntaxError(interp, envPtr);
}
Tcl_RestoreInterpState(interp, save);
convert = 0;
} else {
nodePtr = nodes + next;
}
}
}
}
/*
*----------------------------------------------------------------------
*
* TclSingleOpCmd --
* Implements the commands: ~, !, <<, >>, %, !=, ne, in, ni
* in the ::tcl::mathop namespace. These commands have no
* extension to arbitrary arguments; they accept only exactly one
* or exactly two arguments as suitable for the operator.
*
* Results:
* A standard Tcl return code and result left in interp.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
TclSingleOpCmd(
ClientData clientData,
Tcl_Interp *interp,
int objc,
Tcl_Obj *const objv[])
{
TclOpCmdClientData *occdPtr = (TclOpCmdClientData *)clientData;
unsigned char lexeme;
OpNode nodes[2];
Tcl_Obj *const *litObjv = objv + 1;
if (objc != 1+occdPtr->i.numArgs) {
Tcl_WrongNumArgs(interp, 1, objv, occdPtr->expected);
return TCL_ERROR;
}
ParseLexeme(occdPtr->op, strlen(occdPtr->op), &lexeme, NULL);
nodes[0].lexeme = START;
nodes[0].mark = MARK_RIGHT;
nodes[0].right = 1;
nodes[1].lexeme = lexeme;
if (objc == 2) {
nodes[1].mark = MARK_RIGHT;
} else {
nodes[1].mark = MARK_LEFT;
nodes[1].left = OT_LITERAL;
}
nodes[1].right = OT_LITERAL;
nodes[1].p.parent = 0;
return ExecConstantExprTree(interp, nodes, 0, &litObjv);
}
/*
*----------------------------------------------------------------------
*
* TclSortingOpCmd --
* Implements the commands: <, <=, >, >=, ==, eq
* in the ::tcl::mathop namespace. These commands are defined for
* arbitrary number of arguments by computing the AND of the base
* operator applied to all neighbor argument pairs.
*
* Results:
* A standard Tcl return code and result left in interp.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
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;
Tcl_Obj *const *litObjPtrPtr = litObjv;
ParseLexeme(occdPtr->op, strlen(occdPtr->op), &lexeme, NULL);
litObjv[0] = objv[1];
nodes[0].lexeme = START;
nodes[0].mark = MARK_RIGHT;
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].mark = MARK_LEFT;
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)].mark = MARK_LEFT;
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].mark = MARK_LEFT;
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 = ExecConstantExprTree(interp, nodes, 0, &litObjPtrPtr);
TclStackFree(interp, nodes);
TclStackFree(interp, litObjv);
}
return code;
}
/*
*----------------------------------------------------------------------
*
* TclVariadicOpCmd --
* Implements the commands: +, *, &, |, ^, **
* in the ::tcl::mathop namespace. These commands are defined for
* arbitrary number of arguments by repeatedly applying the base
* operator with suitable associative rules. When fewer than two
* arguments are provided, suitable identity values are returned.
*
* Results:
* A standard Tcl return code and result left in interp.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
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->i.identity));
return TCL_OK;
}
ParseLexeme(occdPtr->op, strlen(occdPtr->op), &lexeme, NULL);
lexeme |= BINARY;
if (objc == 2) {
Tcl_Obj *litObjv[2];
OpNode nodes[2];
int decrMe = 0;
Tcl_Obj *const *litObjPtrPtr = litObjv;
if (lexeme == EXPON) {
litObjv[1] = Tcl_NewIntObj(occdPtr->i.identity);
Tcl_IncrRefCount(litObjv[1]);
decrMe = 1;
litObjv[0] = objv[1];
nodes[0].lexeme = START;
nodes[0].mark = MARK_RIGHT;
nodes[0].right = 1;
nodes[1].lexeme = lexeme;
nodes[1].mark = MARK_LEFT;
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->i.identity);
}
Tcl_IncrRefCount(litObjv[0]);
litObjv[1] = objv[1];
nodes[0].lexeme = START;
nodes[0].mark = MARK_RIGHT;
nodes[0].right = 1;
nodes[1].lexeme = lexeme;
nodes[1].mark = MARK_LEFT;
nodes[1].left = OT_LITERAL;
nodes[1].right = OT_LITERAL;
nodes[1].p.parent = 0;
}
code = ExecConstantExprTree(interp, nodes, 0, &litObjPtrPtr);
Tcl_DecrRefCount(litObjv[decrMe]);
return code;
} else {
Tcl_Obj *const *litObjv = objv + 1;
OpNode *nodes = (OpNode *) TclStackAlloc(interp,
(objc-1)*sizeof(OpNode));
int i, lastOp = OT_LITERAL;
nodes[0].lexeme = START;
nodes[0].mark = MARK_RIGHT;
if (lexeme == EXPON) {
for (i=objc-2; i>0; i-- ) {
nodes[i].lexeme = lexeme;
nodes[i].mark = MARK_LEFT;
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].mark = MARK_LEFT;
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 = ExecConstantExprTree(interp, nodes, 0, &litObjv);
TclStackFree(interp, nodes);
return code;
}
}
/*
*----------------------------------------------------------------------
*
* TclNoIdentOpCmd --
* Implements the commands: -, /
* in the ::tcl::mathop namespace. These commands are defined for
* arbitrary non-zero number of arguments by repeatedly applying
* the base operator with suitable associative rules. When no
* arguments are provided, an error is raised.
*
* Results:
* A standard Tcl return code and result left in interp.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
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:
*/
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