From e0da6e47c9d1eaafcbe2b26c2ac9c5304b755efd Mon Sep 17 00:00:00 2001
From: "Arnold D. Robbins" <arnold@skeeve.com>
Date: Thu, 18 Apr 2019 20:15:15 +0300
Subject: [PATCH] Fix core dump upon syntax error.

---
 awk.h            |  1 +
 awkgram.c        |  2 +-
 awkgram.y        |  2 +-
 command.c        | 14 +++++++-------
 command.y        | 14 +++++++-------
 main.c           |  6 ++++++
 test/Makefile.am |  4 +++-
 test/Makefile.in |  9 ++++++++-
 test/Maketests   |  5 +++++
 test/synerr3.awk |  1 +
 test/synerr3.ok  |  5 +++++
 11 files changed, 45 insertions(+), 18 deletions(-)
 create mode 100644 test/synerr3.awk
 create mode 100644 test/synerr3.ok

diff --git a/awk.h b/awk.h
index cdf683d1..679cbde5 100644
--- a/awk.h
+++ b/awk.h
@@ -1114,6 +1114,7 @@ extern NODE *Null_field;
 extern NODE **fields_arr;
 extern int sourceline;
 extern char *source;
+extern int errcount;
 extern int (*interpret)(INSTRUCTION *);	/* interpreter routine */
 extern NODE *(*make_number)(double);	/* double instead of AWKNUM on purpose */
 extern NODE *(*str2number)(NODE *);
diff --git a/awkgram.c b/awkgram.c
index d3c4e830..878a83a9 100644
--- a/awkgram.c
+++ b/awkgram.c
@@ -173,7 +173,7 @@ static int continue_allowed;	/* kludge for continue */
 static char *tokstart = NULL;
 static char *tok = NULL;
 static char *tokend;
-static int errcount = 0;
+int errcount = 0;
 
 extern char *source;
 extern int sourceline;
diff --git a/awkgram.y b/awkgram.y
index caed09e0..c16616f9 100644
--- a/awkgram.y
+++ b/awkgram.y
@@ -133,7 +133,7 @@ static int continue_allowed;	/* kludge for continue */
 static char *tokstart = NULL;
 static char *tok = NULL;
 static char *tokend;
-static int errcount = 0;
+int errcount = 0;
 
 extern char *source;
 extern int sourceline;
diff --git a/command.c b/command.c
index 0876f02f..90742dd7 100644
--- a/command.c
+++ b/command.c
@@ -90,7 +90,7 @@ static bool want_nodeval = false;
 static int cmd_idx = -1;		/* index of current command in cmd table */
 static int repeat_idx = -1;		/* index of last repeatable command in command table */
 static CMDARG *arg_list = NULL;		/* list of arguments */
-static long errcount = 0;
+static long dbg_errcount = 0;
 static char *lexptr_begin = NULL;
 static bool in_commands = false;
 static int num_dim;
@@ -1548,7 +1548,7 @@ yyreduce:
   case 5:
 #line 130 "command.y" /* yacc.c:1646  */
     {
-		if (errcount == 0 && cmd_idx >= 0) {
+		if (dbg_errcount == 0 && cmd_idx >= 0) {
 			Func_cmd cmdfunc;
 			bool terminate = false;
 			CMDARG *args;
@@ -1616,7 +1616,7 @@ yyreduce:
   case 23:
 #line 219 "command.y" /* yacc.c:1646  */
     {
-		if (errcount == 0) {
+		if (dbg_errcount == 0) {
 			/* don't free arg_list;	passed on to statement_list
 			 * non-terminal (empty rule action). See below.
 			 */
@@ -1783,7 +1783,7 @@ yyreduce:
 		if ((yyvsp[0]) != NULL)
 			num = (yyvsp[0])->a_int;
 
-		if (errcount != 0)
+		if (dbg_errcount != 0)
 			;
 		else if (in_commands)
 			yyerror(_("Can't use command `commands' for breakpoint/watchpoint commands"));
@@ -2766,7 +2766,7 @@ yyerror(const char *mesg, ...)
 	vfprintf(out_fp, mesg, args);
 	fprintf(out_fp, "\n");
 	va_end(args);
-	errcount++;
+	dbg_errcount++;
 	repeat_idx = -1;
 }
 
@@ -2788,9 +2788,9 @@ yylex(void)
 
 	yylval = (CMDARG *) NULL;
 
-	if (errcount > 0 && lexptr_begin == NULL) {
+	if (dbg_errcount > 0 && lexptr_begin == NULL) {
 		/* fake a new line */
-		errcount = 0;
+		dbg_errcount = 0;
 		return '\n';
 	}
 
diff --git a/command.y b/command.y
index 58880dee..96148eff 100644
--- a/command.y
+++ b/command.y
@@ -44,7 +44,7 @@ static bool want_nodeval = false;
 static int cmd_idx = -1;		/* index of current command in cmd table */
 static int repeat_idx = -1;		/* index of last repeatable command in command table */
 static CMDARG *arg_list = NULL;		/* list of arguments */
-static long errcount = 0;
+static long dbg_errcount = 0;
 static char *lexptr_begin = NULL;
 static bool in_commands = false;
 static int num_dim;
@@ -128,7 +128,7 @@ line
 	: nls
 	| command nls
 	  {
-		if (errcount == 0 && cmd_idx >= 0) {
+		if (dbg_errcount == 0 && cmd_idx >= 0) {
 			Func_cmd cmdfunc;
 			bool terminate = false;
 			CMDARG *args;
@@ -217,7 +217,7 @@ set_want_nodeval
 eval_prologue
 	: D_EVAL set_want_nodeval opt_param_list nls
 	  {
-		if (errcount == 0) {
+		if (dbg_errcount == 0) {
 			/* don't free arg_list;	passed on to statement_list
 			 * non-terminal (empty rule action). See below.
 			 */
@@ -335,7 +335,7 @@ command
 		if ($2 != NULL)
 			num = $2->a_int;
 
-		if (errcount != 0)
+		if (dbg_errcount != 0)
 			;
 		else if (in_commands)
 			yyerror(_("Can't use command `commands' for breakpoint/watchpoint commands"));
@@ -1017,7 +1017,7 @@ yyerror(const char *mesg, ...)
 	vfprintf(out_fp, mesg, args);
 	fprintf(out_fp, "\n");
 	va_end(args);
-	errcount++;
+	dbg_errcount++;
 	repeat_idx = -1;
 }
 
@@ -1039,9 +1039,9 @@ yylex(void)
 
 	yylval = (CMDARG *) NULL;
 
-	if (errcount > 0 && lexptr_begin == NULL) {
+	if (dbg_errcount > 0 && lexptr_begin == NULL) {
 		/* fake a new line */
-		errcount = 0;
+		dbg_errcount = 0;
 		return '\n';
 	}
 
diff --git a/main.c b/main.c
index 25a628ba..754f2050 100644
--- a/main.c
+++ b/main.c
@@ -1223,6 +1223,9 @@ catchsig(int sig)
 	        || sig == SIGBUS
 #endif
 	) {
+		if (errcount > 0)	// assume a syntax error corrupted our data structures
+			exit(EXIT_FATAL);
+
 		set_loc(__FILE__, __LINE__);
 		msg(_("fatal error: internal error"));
 		/* fatal won't abort() if not compiled for debugging */
@@ -1240,6 +1243,9 @@ catchsig(int sig)
 static int
 catchsegv(void *fault_address, int serious)
 {
+	if (errcount > 0)	// assume a syntax error corrupted our data structures
+		exit(EXIT_FATAL);
+
 	set_loc(__FILE__, __LINE__);
 	msg(_("fatal error: internal error: segfault"));
 	fflush(NULL);
diff --git a/test/Makefile.am b/test/Makefile.am
index 13f53f95..98d4d1d0 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1141,6 +1141,8 @@ EXTRA_DIST = \
 	synerr1.ok \
 	synerr2.awk \
 	synerr2.ok \
+	synerr3.awk \
+	synerr3.ok \
 	tailrecurse.awk \
 	tailrecurse.ok \
 	testext.ok \
@@ -1261,7 +1263,7 @@ BASIC_TESTS = \
 	scalar sclforin sclifin setrec0 setrec1 \
 	sigpipe1 sortempty sortglos splitargv splitarr \
 	splitdef splitvar splitwht status-close strcat1 strnum1 strnum2 strtod \
-	subamp subback subi18n subsepnm subslash substr swaplns synerr1 synerr2 \
+	subamp subback subi18n subsepnm subslash substr swaplns synerr1 synerr2 synerr3 \
 	tailrecurse tradanch tweakfld \
 	uninit2 uninit3 uninit4 uninit5 uninitialized unterm uparrfs uplus \
 	wideidx wideidx2 widesub widesub2 widesub3 widesub4 wjposer1 \
diff --git a/test/Makefile.in b/test/Makefile.in
index b23bd8ea..5b348528 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -1399,6 +1399,8 @@ EXTRA_DIST = \
 	synerr1.ok \
 	synerr2.awk \
 	synerr2.ok \
+	synerr3.awk \
+	synerr3.ok \
 	tailrecurse.awk \
 	tailrecurse.ok \
 	testext.ok \
@@ -1518,7 +1520,7 @@ BASIC_TESTS = \
 	scalar sclforin sclifin setrec0 setrec1 \
 	sigpipe1 sortempty sortglos splitargv splitarr \
 	splitdef splitvar splitwht status-close strcat1 strnum1 strnum2 strtod \
-	subamp subback subi18n subsepnm subslash substr swaplns synerr1 synerr2 \
+	subamp subback subi18n subsepnm subslash substr swaplns synerr1 synerr2 synerr3 \
 	tailrecurse tradanch tweakfld \
 	uninit2 uninit3 uninit4 uninit5 uninitialized unterm uparrfs uplus \
 	wideidx wideidx2 widesub widesub2 widesub3 widesub4 wjposer1 \
@@ -3944,6 +3946,11 @@ synerr2:
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
+synerr3:
+	@echo $@
+	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
+
 tailrecurse:
 	@echo $@
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/Maketests b/test/Maketests
index f5840e5f..314f0c0b 100644
--- a/test/Maketests
+++ b/test/Maketests
@@ -1007,6 +1007,11 @@ synerr2:
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
+synerr3:
+	@echo $@
+	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
+
 tailrecurse:
 	@echo $@
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/synerr3.awk b/test/synerr3.awk
new file mode 100644
index 00000000..49b9e30a
--- /dev/null
+++ b/test/synerr3.awk
@@ -0,0 +1 @@
+for (i = ) in foo bar baz
diff --git a/test/synerr3.ok b/test/synerr3.ok
new file mode 100644
index 00000000..b8b9dd89
--- /dev/null
+++ b/test/synerr3.ok
@@ -0,0 +1,5 @@
+gawk: synerr3.awk:1: for (i = ) in foo bar baz
+gawk: synerr3.awk:1: ^ syntax error
+gawk: synerr3.awk:1: for (i = ) in foo bar baz
+gawk: synerr3.awk:1:          ^ syntax error
+EXIT CODE: 2
-- 
2.19.1