From 324e5e581b5034b6f1bd8a944a71cfa57e926a50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 24 Aug 2019 20:15:52 +0200
Subject: [PATCH] Redundant assignments: Fix false positive when reassignment
 expression contains assembler

---
 lib/astutils.cpp   | 12 ++++++++++++
 test/testother.cpp |  8 ++++++++
 2 files changed, 20 insertions(+)

diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index c59d5531f..3541ecd9f 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -1331,6 +1331,15 @@ static bool nonLocal(const Variable* var, bool deref)
     return !var || (!var->isLocal() && !var->isArgument()) || (deref && var->isArgument() && var->isPointer()) || var->isStatic() || var->isReference() || var->isExtern();
 }
 
+static bool hasGccCompoundStatement(const Token *tok)
+{
+    if (!tok)
+        return false;
+    if (tok->str() == "{" && Token::simpleMatch(tok->previous(), "( {"))
+        return true;
+    return hasGccCompoundStatement(tok->astOperand1()) || hasGccCompoundStatement(tok->astOperand2());
+}
+
 static bool hasFunctionCall(const Token *tok)
 {
     if (!tok)
@@ -1688,6 +1697,9 @@ struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const
                         return Result(Result::Type::READ);
                     continue;
                 }
+                // ({ .. })
+                if (hasGccCompoundStatement(parent->astParent()->astOperand2()))
+                    return Result(Result::Type::BAILOUT);
                 const bool reassign = isSameExpression(mCpp, false, expr, parent, mLibrary, false, false, nullptr);
                 if (reassign)
                     return Result(Result::Type::WRITE, parent->astParent());
diff --git a/test/testother.cpp b/test/testother.cpp
index d55c99c37..eebe94da5 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -6172,6 +6172,14 @@ private:
               "}");
         ASSERT_EQUALS("", errout.str());
 
+        // ({ })
+        check("void f() {\n"
+              "  int x;\n"
+              "  x = 321;\n"
+              "  x = ({ asm(123); })\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+
         // from #3103 (avoid a false negative)
         check("int foo(){\n"
               "    int x;\n"