From 2ede5a7546215ba6dd328c707629f789b90edf31 Mon Sep 17 00:00:00 2001
From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Tue, 26 May 2015 21:34:56 +0100
Subject: [PATCH] Output user-defines start label in the appropriate place.

Before this commit, given the following example:
    /*!re2c
            re2c:startlabel = "start";
            [^]* {}
    */
re2c would generate the following code:
    {
            YYCTYPE yych;
            goto yy0;
    yy1:
    start:
            ++YYCURSOR;
    yy0:
            if (YYLIMIT <= YYCURSOR) YYFILL(1);
            yych = *YYCURSOR;
            goto yy1;
            {}
    }
where "start:" falsely corresponds to "yy1:" rather to "yy0:".
(The important property of this example is that DFA has arrows
to initial state.) This commit fixes this behavior:
    {
            YYCTYPE yych;
    start:
            goto yy0;
    yy1:
            ++YYCURSOR;
    yy0:
            if (YYLIMIT <= YYCURSOR) YYFILL(1);
            yych = *YYCURSOR;
            goto yy1;
            {}
    }
---
 re2c/src/codegen/emit_action.cc               |  5 -----
 re2c/src/codegen/emit_dfa.cc                  |  8 ++++----
 .../segfault_full_range_star_startlabel.ci.c  | 20 +++++++++++++++++++
 .../segfault_full_range_star_startlabel.ci.re |  4 ++++
 .../segfault_full_range_star_startlabel.i.c   | 15 ++++++++++++++
 .../segfault_full_range_star_startlabel.i.re  |  4 ++++
 6 files changed, 47 insertions(+), 9 deletions(-)
 create mode 100644 re2c/test/segfault_full_range_star_startlabel.ci.c
 create mode 100644 re2c/test/segfault_full_range_star_startlabel.ci.re
 create mode 100644 re2c/test/segfault_full_range_star_startlabel.i.c
 create mode 100644 re2c/test/segfault_full_range_star_startlabel.i.re

diff --git a/re2c/src/codegen/emit_action.cc b/re2c/src/codegen/emit_action.cc
index d6eaa174..0efca68e 100644
--- a/re2c/src/codegen/emit_action.cc
+++ b/re2c/src/codegen/emit_action.cc
@@ -80,11 +80,6 @@ void emit_initial (OutputFile & o, uint32_t ind, bool & readCh, const State * co
 		return;
 	}
 
-	if (!cFlag && !startLabelName.empty())
-	{
-		o << startLabelName << ":\n";
-	}
-
 	if (vUsedLabels.count(s->label))
 	{
 		if (s->link)
diff --git a/re2c/src/codegen/emit_dfa.cc b/re2c/src/codegen/emit_dfa.cc
index cd3acaff..25b6bdb7 100644
--- a/re2c/src/codegen/emit_dfa.cc
+++ b/re2c/src/codegen/emit_dfa.cc
@@ -168,10 +168,10 @@ void DFA::emit(Output & output, uint32_t& ind, const RegExpMap* specMap, const s
 			{
 				o << labelPrefix << prolog_label << ":\n";
 			}
-			if (!startLabelName.empty())
-			{
-				o << startLabelName << ":\n";
-			}
+		}
+		if (!startLabelName.empty())
+		{
+			o << startLabelName << ":\n";
 		}
 		genCondGoto(o, ind, *specMap);
 	}
diff --git a/re2c/test/segfault_full_range_star_startlabel.ci.c b/re2c/test/segfault_full_range_star_startlabel.ci.c
new file mode 100644
index 00000000..fcf4284a
--- /dev/null
+++ b/re2c/test/segfault_full_range_star_startlabel.ci.c
@@ -0,0 +1,20 @@
+/* Generated by re2c */
+
+{
+	YYCTYPE yych;
+start:
+	switch (YYGETCONDITION()) {
+	case yycc1: goto yyc_c1;
+	}
+/* *********************************** */
+yyc_c1:
+	goto yy1;
+yy2:
+	++YYCURSOR;
+yy1:
+	if (YYLIMIT <= YYCURSOR) YYFILL(1);
+	yych = *YYCURSOR;
+	goto yy2;
+	{}
+}
+
diff --git a/re2c/test/segfault_full_range_star_startlabel.ci.re b/re2c/test/segfault_full_range_star_startlabel.ci.re
new file mode 100644
index 00000000..ace5767f
--- /dev/null
+++ b/re2c/test/segfault_full_range_star_startlabel.ci.re
@@ -0,0 +1,4 @@
+/*!re2c
+	re2c:startlabel = "start";
+	<c1> [^]*	{}
+*/
diff --git a/re2c/test/segfault_full_range_star_startlabel.i.c b/re2c/test/segfault_full_range_star_startlabel.i.c
new file mode 100644
index 00000000..e43c5199
--- /dev/null
+++ b/re2c/test/segfault_full_range_star_startlabel.i.c
@@ -0,0 +1,15 @@
+/* Generated by re2c */
+
+{
+	YYCTYPE yych;
+start:
+	goto yy0;
+yy1:
+	++YYCURSOR;
+yy0:
+	if (YYLIMIT <= YYCURSOR) YYFILL(1);
+	yych = *YYCURSOR;
+	goto yy1;
+	{}
+}
+
diff --git a/re2c/test/segfault_full_range_star_startlabel.i.re b/re2c/test/segfault_full_range_star_startlabel.i.re
new file mode 100644
index 00000000..2990c03b
--- /dev/null
+++ b/re2c/test/segfault_full_range_star_startlabel.i.re
@@ -0,0 +1,4 @@
+/*!re2c
+	re2c:startlabel = "start";
+	[^]*	{}
+*/
-- 
2.40.0