From 77cd6c194f5f44e13b0f69fa69942f04b1151a8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 22 Oct 2016 12:24:15 +0200
Subject: [PATCH] ValueFlow: Set 'known' property for function return values

---
 lib/valueflow.cpp      | 12 +++++-------
 test/testvalueflow.cpp |  3 +++
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index b43e6cd27..e89fad9e6 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -2484,9 +2484,9 @@ static void valueFlowFunctionDefaultParameter(TokenList *tokenlist, SymbolDataba
     }
 }
 
-static bool constval(const Token * tok)
+static bool isKnown(const Token * tok)
 {
-    return tok && tok->values.size() == 1U && tok->values.front().varId == 0U;
+    return tok && tok->hasKnownIntValue();
 }
 
 static void valueFlowFunctionReturn(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
@@ -2499,9 +2499,9 @@ static void valueFlowFunctionReturn(TokenList *tokenlist, ErrorLogger *errorLogg
         std::vector<MathLib::bigint> parvalues;
         if (tok->astOperand2()) {
             const Token *partok = tok->astOperand2();
-            while (partok && partok->str() == "," && constval(partok->astOperand2()))
+            while (partok && partok->str() == "," && isKnown(partok->astOperand2()))
                 partok = partok->astOperand1();
-            if (!constval(partok))
+            if (!isKnown(partok))
                 continue;
             parvalues.push_back(partok->values.front().intvalue);
             partok = partok->astParent();
@@ -2545,9 +2545,7 @@ static void valueFlowFunctionReturn(TokenList *tokenlist, ErrorLogger *errorLogg
                 &error);
         if (!error) {
             ValueFlow::Value v(result);
-            if (functionScope->classStart->next()->astOperand1()->hasKnownIntValue())
-                v.setKnown();
-            // TODO: Known input parameters => known return value
+            v.setKnown();
             setTokenValue(tok, v);
         }
     }
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index ae4e2eacf..90ebcd762 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -1768,6 +1768,7 @@ private:
                "    x = 10 - f1(2);\n"
                "}";
         ASSERT_EQUALS(7, valueOfTok(code, "-").intvalue);
+        ASSERT_EQUALS(true, valueOfTok(code, "-").isKnown());
 
         code = "int add(int x, int y) {\n"
                "  return x+y;\n"
@@ -1776,10 +1777,12 @@ private:
                "    x = 1 * add(10+1,4);\n"
                "}";
         ASSERT_EQUALS(15, valueOfTok(code, "*").intvalue);
+        ASSERT_EQUALS(true, valueOfTok(code, "*").isKnown());
 
         code = "int one() { return 1; }\n"
                "void f() { x = 1 * one(); }";
         ASSERT_EQUALS(1, valueOfTok(code, "*").intvalue);
+        ASSERT_EQUALS(true, valueOfTok(code, "*").isKnown());
     }
 
     void valueFlowFunctionDefaultParameter() {