From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Mon, 10 Aug 2015 09:32:31 +0000 (+0100)
Subject: Explicit cast of pointer difference to uint32_t: it seems to be safe from the code.
X-Git-Tag: 0.15~144
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=46c5baeae0d3b23f6c2468905a009dd18efd0e11;p=re2c

Explicit cast of pointer difference to uint32_t: it seems to be safe from the code.

In theory, this function returns the number of 'Span's in the newly
constructed 'Span' array, so it must be a non-negative integer number
that fits into 32 bits and the cast is safe.

In practice, 'x0' variable stays unchanged in this function, while
'x' variable's value can only increase: whenever it can be (conditionally)
decremented, it is always unconditionally incremented. So 'x - x0'
must be non-negative.

Fixes [-Wconversion] warning.
---

diff --git a/re2c/src/codegen/prepare_dfa.cc b/re2c/src/codegen/prepare_dfa.cc
index cc9b197a..7822d285 100644
--- a/re2c/src/codegen/prepare_dfa.cc
+++ b/re2c/src/codegen/prepare_dfa.cc
@@ -76,7 +76,7 @@ static uint32_t merge(Span *x0, State *fg, State *bg)
 
 			if (nf == 0 && nb == 0)
 			{
-				return x - x0;
+				return static_cast<uint32_t> (x - x0);
 			}
 		}