From b5441f223475e842166d861539c8fca39bfb9991 Mon Sep 17 00:00:00 2001
From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Fri, 28 Aug 2015 23:15:40 +0100
Subject: [PATCH] No need to NULL-terminate array of known size.

For some reason (which I yet do not understand) re2c uses size of DFA
state's "kernel" to determine whether a new state should be constructed
or some already constructed state (of the same "kernel" size) will do.

Since re2c knows "kernel" size for each state anyway, there's no need
to NULL-terminate "kernel" array while iterating over it: we can use
pre-calculated size instead.
---
 re2c/src/ir/dfa/dfa.cc  | 31 ++++++++++++++-----------------
 re2c/src/ir/dfa/state.h |  2 +-
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/re2c/src/ir/dfa/dfa.cc b/re2c/src/ir/dfa/dfa.cc
index eeccf157..91b53333 100644
--- a/re2c/src/ir/dfa/dfa.cc
+++ b/re2c/src/ir/dfa/dfa.cc
@@ -64,8 +64,9 @@ DFA::DFA(Ins *ins, uint32_t ni, uint32_t lb, uint32_t ub, const Char *rep)
 
 		s->rule = NULL;
 
-		for (Ins ** iP = s->kernel, * i; (i = *iP); ++iP)
+		for (uint32_t k = 0; k < s->kCount; ++k)
 		{
+			Ins * i = s->kernel[k];
 			if (i->i.tag == CHAR)
 			{
 				for (Ins *j = i + 1; j < (Ins*) i->i.link; ++j)
@@ -152,33 +153,29 @@ void DFA::addState(State **a, State *s)
 
 State *DFA::findState(Ins **kernel, Ins ** kernel_end)
 {
-	Ins ** cP = kernel;
-
-	for (Ins ** iP = kernel; iP < kernel_end; ++iP)
+	uint32_t kCount = 0;
+	for (Ins ** i = kernel; i < kernel_end; ++i)
 	{
-		Ins * i = *iP;
-		if (i->i.tag == CHAR || i->i.tag == TERM || i->i.tag == CTXT)
+		Ins * ins = *i;
+		if (ins->i.tag == CHAR || ins->i.tag == TERM || ins->i.tag == CTXT)
 		{
-			*cP++ = i;
+			kernel[kCount++] = ins;
 		}
 		else
 		{
-			unmark(i);
+			unmark (ins);
 		}
 	}
 
-	const ptrdiff_t kCount = cP - kernel;
-	kernel[kCount] = NULL;
-
 	State * s;
 	for (s = head; s; s = s->next)
 	{
 		if (s->kCount == kCount)
 		{
 			bool marked = true;
-			for (Ins ** iP = s->kernel, * i; marked && (i = *iP); ++iP)
+			for (uint32_t i = 0; marked && i < s->kCount; ++i)
 			{
-				marked = isMarked (i);
+				marked = isMarked (s->kernel[i]);
 			}
 			if (marked)
 			{
@@ -192,15 +189,15 @@ State *DFA::findState(Ins **kernel, Ins ** kernel_end)
 		s = new State;
 		addState(tail, s);
 		s->kCount = kCount;
-		s->kernel = new Ins * [kCount + 1];
-		memcpy(s->kernel, kernel, (kCount + 1)*sizeof(Ins*));
+		s->kernel = new Ins * [kCount];
+		memcpy(s->kernel, kernel, kCount * sizeof (Ins *));
 		s->link = toDo;
 		toDo = s;
 	}
 
-	for (Ins ** iP = kernel, * i; (i = *iP); ++iP)
+	for (uint32_t i = 0; i < kCount; ++i)
 	{
-		unmark(i);
+		unmark (kernel[i]);
 	}
 
 	return s;
diff --git a/re2c/src/ir/dfa/state.h b/re2c/src/ir/dfa/state.h
index 6171223e..41af7dfd 100644
--- a/re2c/src/ir/dfa/state.h
+++ b/re2c/src/ir/dfa/state.h
@@ -17,7 +17,7 @@ public:
 	State * next;
 	State * link;
 	uint32_t depth; // for finding SCCs
-	ptrdiff_t kCount;
+	uint32_t kCount;
 	Ins ** kernel;
 
 	bool isPreCtxt;
-- 
2.40.0