From bf3833dad5983797e5747ef36ab06eec5a4bbc49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Tue, 29 Sep 2020 13:35:39 +0200
Subject: [PATCH] Avoid constStatement false positives for 'foo() || x=5'.
 Found in daca@home.

---
 lib/checkother.cpp               | 21 +++++++++++++++++++++
 test/testincompletestatement.cpp |  8 ++++++++
 2 files changed, 29 insertions(+)

diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 810ef0f9d..46d4d57ce 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1665,6 +1665,27 @@ void CheckOther::checkIncompleteStatement()
             continue;
         if (tok->str() == "," && Token::simpleMatch(tok->astTop()->previous(), "for ("))
             continue;
+
+        // Do not warn for statement when both lhs and rhs has side effects:
+        //   dostuff() || x=213;
+        if (Token::Match(tok, "%oror%|&&")) {
+            bool warn = false;
+            visitAstNodes(tok, [&warn](const Token *child) {
+                if (Token::Match(child, "%oror%|&&"))
+                    return ChildrenToVisit::op1_and_op2;
+                if (child->isAssignmentOp())
+                    return ChildrenToVisit::none;
+                if (child->tokType() == Token::Type::eIncDecOp)
+                    return ChildrenToVisit::none;
+                if (Token::Match(child->previous(), "%name% ("))
+                    return ChildrenToVisit::none;
+                warn = true;
+                return ChildrenToVisit::done;
+            });
+            if (!warn)
+                continue;
+        }
+
         const Token *rtok = nextAfterAstRightmostLeaf(tok);
         if (!Token::simpleMatch(tok->astParent(), ";") && !Token::simpleMatch(rtok, ";") &&
             !Token::Match(tok->previous(), ";|}|{ %any% ;"))
diff --git a/test/testincompletestatement.cpp b/test/testincompletestatement.cpp
index 57d4c49a0..4495d0972 100644
--- a/test/testincompletestatement.cpp
+++ b/test/testincompletestatement.cpp
@@ -90,6 +90,7 @@ private:
         TEST_CASE(vardecl);
         TEST_CASE(archive);             // ar & x
         TEST_CASE(ast);
+        TEST_CASE(oror);                // dostuff() || x=32;
     }
 
     void test1() {
@@ -423,6 +424,13 @@ private:
         check("struct c { void a() const { for (int x=0; x;); } };", true);
         ASSERT_EQUALS("", errout.str());
     }
+
+    void oror() {
+        check("void foo() {\n"
+              "    params_given (params, \"overrides\") || (overrides = \"1\");\n"
+              "}", true);
+        ASSERT_EQUALS("", errout.str());
+    }
 };
 
 REGISTER_TEST(TestIncompleteStatement)