diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | generic/tclCompExpr.c | 36 |
2 files changed, 38 insertions, 4 deletions
@@ -1,5 +1,11 @@ 2007-07-09 Don Porter <dgp@users.sourceforge.net> + * generic/tclCompExpr.c: Revision so that the END lexeme never + gets inserted into the parse tree. Later tree traversal never reaches + it since its location in the tree is not variable. Starting and + stopping with the START lexeme (node 0) is sufficient. Also finished + lexeme code commentary. + * generic/tclCompExpr.c: Added missing creation and return of the Tcl_Parse fields that indicate error conditions. [Bug 1749987] diff --git a/generic/tclCompExpr.c b/generic/tclCompExpr.c index 3474562..7741634 100644 --- a/generic/tclCompExpr.c +++ b/generic/tclCompExpr.c @@ -10,7 +10,7 @@ * 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 1.60 2007/07/09 14:51:44 dgp Exp $ + * RCS: @(#) $Id: tclCompExpr.c,v 1.61 2007/07/09 17:34:14 dgp Exp $ */ #include "tclInt.h" @@ -70,7 +70,7 @@ /* Leaf lexemes */ #define NUMBER ( LEAF | 1) /* For literal numbers */ -#define SCRIPT ( LEAF | 2) /* Command substitution; [foo] */ +#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 */ @@ -163,8 +163,33 @@ * ParseExpr(). */ #define IN_LIST ( BINARY | 25) #define NOT_IN_LIST ( BINARY | 26) -#define CLOSE_PAREN ( BINARY | 27) /**/ -#define END ( BINARY | 28) /**/ +#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. */ /* * Integer codes indicating the form of an operand of an operator. @@ -793,6 +818,9 @@ ParseExpr( code = TCL_ERROR; continue; } + if (lexeme == END) { + continue; + } /* * Link orphan as left operand of new node. |