summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authordgp <dgp@users.sourceforge.net>2007-07-12 22:13:12 (GMT)
committerdgp <dgp@users.sourceforge.net>2007-07-12 22:13:12 (GMT)
commit63bfe35d1acdbed6099149dc3b8cbf5ea1c8413d (patch)
treeee388d2cd0d0e7be14d004485e1bc615ec7f936d
parent38001ef18f91865e3e510aa9e641e81e664413e8 (diff)
downloadtcl-63bfe35d1acdbed6099149dc3b8cbf5ea1c8413d.zip
tcl-63bfe35d1acdbed6099149dc3b8cbf5ea1c8413d.tar.gz
tcl-63bfe35d1acdbed6099149dc3b8cbf5ea1c8413d.tar.bz2
additional commentary
-rw-r--r--generic/tclCompExpr.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/generic/tclCompExpr.c b/generic/tclCompExpr.c
index f8277d4..da9007f 100644
--- a/generic/tclCompExpr.c
+++ b/generic/tclCompExpr.c
@@ -12,7 +12,7 @@
* 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 1.67 2007/07/12 18:48:10 dgp Exp $
+ * RCS: @(#) $Id: tclCompExpr.c,v 1.68 2007/07/12 22:13:12 dgp Exp $
*/
#include "tclInt.h"
@@ -638,7 +638,7 @@ ParseExpr(
lexeme |= BINARY;
}
}
- }
+ } /* Uncategorized lexemes */
/*
* Handle lexeme based on its category.
@@ -846,7 +846,7 @@ ParseExpr(
}
lastParsed = OT_TOKENS;
break;
- }
+ } /* case LEAF */
case UNARY:
if (NotOperator(lastParsed)) {
@@ -1078,26 +1078,39 @@ ParseExpr(
lastParsed = nodesUsed;
nodesUsed++;
break;
- }
- }
+ } /* case BINARY */
+ } /* lexeme handler */
+
+ /* Advance past the just-parsed lexeme */
start += scanned;
numBytes -= scanned;
- }
+ } /* main parsing loop */
+ /* In case of any error, we free any partial parse tree we've built. */
if (code != TCL_OK && nodes != NULL) {
ckfree((char*) nodes);
}
if (code == TCL_OK) {
+ /* No error, transfer the parse tree to the caller */
*opTreePtr = nodes;
} else 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)
@@ -1110,12 +1123,14 @@ ParseExpr(
? 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\")",
@@ -1123,6 +1138,10 @@ ParseExpr(
parsePtr->string, (numBytes < limit) ? "" : "..."));
}
+ /*
+ * Any errors that didn't get a suitable parsePtr->errorType,
+ * get recorded as syntax errors.
+ */
if (code != TCL_OK && parsePtr->errorType == TCL_PARSE_SUCCESS) {
parsePtr->errorType = TCL_PARSE_SYNTAX;
}