From 19773f886c6550b33f6d9bf7b6cc9f84499828a2 Mon Sep 17 00:00:00 2001
From: Christophe Geuzaine <cgeuzaine@ulg.ac.be>
Date: Wed, 12 May 2004 18:57:48 +0000
Subject: [PATCH] force flex buffer flush after an error
---
MathEval/parser.cpp | 39 +++++++++++++++++++++++----------------
MathEval/parser.y | 9 ++++++++-
MathEval/scanner.cpp | 6 ++++--
MathEval/scanner.l | 4 +++-
4 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/MathEval/parser.cpp b/MathEval/parser.cpp
index 97048d8755..8944f5f000 100644
--- a/MathEval/parser.cpp
+++ b/MathEval/parser.cpp
@@ -54,7 +54,14 @@ int yyerror (char *s);
is generated by scanner generator). */
int yylex (void);
-#line 41 "parser.y"
+/* Function used to flush the internal flex buffer when we exit
+ prematurely (i.e., in case of a parse error) so that the next time
+ we call the scanner, all is nicely reset. Without this, the
+ behaviour of the next call after an error is unpredictable. */
+int force_buffer_flush(void);
+
+
+#line 48 "parser.y"
#ifndef YYSTYPE
typedef union {
Node *node;
@@ -128,8 +135,8 @@ static const short yyrhs[] =
/* YYRLINE[YYN] -- source line where rule number YYN was defined. */
static const short yyrline[] =
{
- 0, 64, 72, 75, 78, 82, 86, 90, 94, 98,
- 102, 106
+ 0, 71, 78, 81, 84, 88, 92, 96, 100, 104,
+ 108, 112
};
#endif
@@ -915,76 +922,75 @@ yyreduce:
switch (yyn) {
case 1:
-#line 64 "parser.y"
+#line 71 "parser.y"
{
matheval_root = yyvsp[-1].node;
- yyerrok;
return 1;
;
break;}
case 2:
-#line 72 "parser.y"
+#line 78 "parser.y"
{
yyval.node = yyvsp[0].node;
;
break;}
case 3:
-#line 75 "parser.y"
+#line 81 "parser.y"
{
yyval.node = yyvsp[0].node;
;
break;}
case 4:
-#line 78 "parser.y"
+#line 84 "parser.y"
{
/* Create addition binary operator node. */
yyval.node = node_create ('b', '+', yyvsp[-2].node, yyvsp[0].node);
;
break;}
case 5:
-#line 82 "parser.y"
+#line 88 "parser.y"
{
/* Create subtraction binary operator node. */
yyval.node = node_create ('b', '-', yyvsp[-2].node, yyvsp[0].node);
;
break;}
case 6:
-#line 86 "parser.y"
+#line 92 "parser.y"
{
/* Create multiplication binary operator node. */
yyval.node = node_create ('b', '*', yyvsp[-2].node, yyvsp[0].node);
;
break;}
case 7:
-#line 90 "parser.y"
+#line 96 "parser.y"
{
/* Create division binary operator node. */
yyval.node = node_create ('b', '/', yyvsp[-2].node, yyvsp[0].node);
;
break;}
case 8:
-#line 94 "parser.y"
+#line 100 "parser.y"
{
/* Create minus unary operator node. */
yyval.node = node_create ('u', '-', yyvsp[0].node);
;
break;}
case 9:
-#line 98 "parser.y"
+#line 104 "parser.y"
{
/* Create exponentiation unary operator node. */
yyval.node = node_create ('b', '^', yyvsp[-2].node, yyvsp[0].node);
;
break;}
case 10:
-#line 102 "parser.y"
+#line 108 "parser.y"
{
/* Create function node. */
yyval.node = node_create ('f', yyvsp[-3].record, yyvsp[-1].node);
;
break;}
case 11:
-#line 106 "parser.y"
+#line 112 "parser.y"
{
yyval.node = yyvsp[-1].node;
;
@@ -1222,7 +1228,7 @@ yyreturn:
#endif
return yyresult;
}
-#line 111 "parser.y"
+#line 117 "parser.y"
int yyerror(char* s)
@@ -1230,5 +1236,6 @@ int yyerror(char* s)
/* Indicate parsing error through appropriate flag and stop
parsing. */
matheval_ok = 0;
+ force_buffer_flush();
return 0;
}
diff --git a/MathEval/parser.y b/MathEval/parser.y
index 7c3d250b11..10db82c2c7 100644
--- a/MathEval/parser.y
+++ b/MathEval/parser.y
@@ -35,6 +35,13 @@ int yyerror (char *s);
/* Function used to tokenize string representing function (this function
is generated by scanner generator). */
int yylex (void);
+
+/* Function used to flush the internal flex buffer when we exit
+ prematurely (i.e., in case of a parse error) so that the next time
+ we call the scanner, all is nicely reset. Without this, the
+ behaviour of the next call after an error is unpredictable. */
+int force_buffer_flush(void);
+
%}
/* Parser semantic values type. */
@@ -63,7 +70,6 @@ int yylex (void);
input
: expression '\n' {
matheval_root = $1;
- yyerrok;
return 1;
}
;
@@ -115,5 +121,6 @@ int yyerror(char* s)
/* Indicate parsing error through appropriate flag and stop
parsing. */
matheval_ok = 0;
+ force_buffer_flush();
return 0;
}
diff --git a/MathEval/scanner.cpp b/MathEval/scanner.cpp
index 67e95880ad..004b773591 100644
--- a/MathEval/scanner.cpp
+++ b/MathEval/scanner.cpp
@@ -20,7 +20,7 @@
/* A lexical scanner generated by flex */
/* Scanner skeleton version:
- * $Header: /cvsroot/gmsh/MathEval/scanner.cpp,v 1.3 2004-05-12 18:38:44 geuzaine Exp $
+ * $Header: /cvsroot/gmsh/MathEval/scanner.cpp,v 1.4 2004-05-12 18:57:48 geuzaine Exp $
*/
#define FLEX_SCANNER
@@ -1687,7 +1687,7 @@ int main()
#undef mewrap
-int mewrap() {return 1;}
+int mewrap() { return 1; }
static int input_from_string (char *buffer, int max_size)
{
@@ -1704,3 +1704,5 @@ static int input_from_string (char *buffer, int max_size)
return count;
}
+
+int force_buffer_flush() { YY_FLUSH_BUFFER; }
diff --git a/MathEval/scanner.l b/MathEval/scanner.l
index 8c6977fd41..b060e2b5e1 100644
--- a/MathEval/scanner.l
+++ b/MathEval/scanner.l
@@ -107,7 +107,7 @@ identifier [a-zA-Z\_][a-zA-Z0-9\_]*
#undef mewrap
-int mewrap() {return 1;}
+int mewrap() { return 1; }
static int input_from_string (char *buffer, int max_size)
{
@@ -124,3 +124,5 @@ static int input_from_string (char *buffer, int max_size)
return count;
}
+
+int force_buffer_flush() { YY_FLUSH_BUFFER; }
--
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