From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Sun, 13 Sep 2020 03:51:17 +0000 (-0700)
Subject: remove undefined behavior in VPSC Constraint output
X-Git-Tag: 2.46.0~20^2^2~73^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3178647a95d4095a03d679e0c2a8bdb8c6ed62f9;p=graphviz

remove undefined behavior in VPSC Constraint output

The address of a reference parameter can never be NULL. A reference parameter
is, definitionally, non-NULL. So taking the address of a reference parameter and
comparing it against NULL is always false. None of the call sites of this
operator passed in NULL, so this change is a no-op from a user perspective, but
it guards against future misuse.

This addresses the following Coverity warning:

  Error: COMPILER_WARNING: [#def230]
  graphviz-2.40.1/lib/vpsc/constraint.cpp: scope_hint: In function 'std::ostream& operator<<(std::ostream&, const Constraint&)'
  graphviz-2.40.1/lib/vpsc/constraint.cpp:46:7: warning: the compiler can assume that the address of 'c' will never be NULL [-Waddress]
  #  if(&c==NULL) {
  #       ^
  #   44|   std::ostream& operator <<(std::ostream &os, const Constraint &c)
  #   45|   {
  #   46|->   if(&c==NULL) {
  #   47|       os<<"NULL";
  #   48|     } else {

Related to #1464.
---

diff --git a/lib/vpsc/constraint.cpp b/lib/vpsc/constraint.cpp
index 10fa5b485..e3561a088 100644
--- a/lib/vpsc/constraint.cpp
+++ b/lib/vpsc/constraint.cpp
@@ -43,10 +43,6 @@ Constraint::~Constraint() {
 }
 std::ostream& operator <<(std::ostream &os, const Constraint &c)
 {
-	if(&c==NULL) {
-		os<<"NULL";
-	} else {
-		os<<*c.left<<"+"<<c.gap<<"<="<<*c.right<<"("<<c.slack()<<")"<<(c.active?"-active":"");
-	}
+	os<<*c.left<<"+"<<c.gap<<"<="<<*c.right<<"("<<c.slack()<<")"<<(c.active?"-active":"");
 	return os;
 }