From 71bf0f076f93571e20b02e94807bcd3bd7810c97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 15 Nov 2015 19:34:36 +0100
Subject: [PATCH] CheckAutoVariables: Handle 'x-y' better in isAutoVarArray

---
 lib/checkautovariables.cpp | 7 +++++++
 test/testautovariables.cpp | 6 ++++++
 2 files changed, 13 insertions(+)

diff --git a/lib/checkautovariables.cpp b/lib/checkautovariables.cpp
index 419383699..4f61f102d 100644
--- a/lib/checkautovariables.cpp
+++ b/lib/checkautovariables.cpp
@@ -99,6 +99,13 @@ bool CheckAutoVariables::isAutoVarArray(const Token *tok)
     if (tok->str() == "+")
         return isAutoVarArray(tok->astOperand1()) || isAutoVarArray(tok->astOperand2());
 
+    // x-intexpr
+    if (tok->str() == "-")
+        return isAutoVarArray(tok->astOperand1()) &&
+               tok->astOperand2() &&
+               tok->astOperand2()->valueType() &&
+               tok->astOperand2()->valueType()->isIntegral();
+
     const Variable *var = tok->variable();
     if (!var)
         return false;
diff --git a/test/testautovariables.cpp b/test/testautovariables.cpp
index 756e33269..c664a108a 100644
--- a/test/testautovariables.cpp
+++ b/test/testautovariables.cpp
@@ -680,6 +680,12 @@ private:
               "    return x+5;\n"
               "}");
         ASSERT_EQUALS("[test.cpp:3]: (error) Pointer to local array variable returned.\n", errout.str());
+
+        check("char *foo(int y) {\n"
+              "    char x[10] = {0};\n"
+              "    return (x+8)-y;\n"
+              "}");
+        ASSERT_EQUALS("[test.cpp:3]: (error) Pointer to local array variable returned.\n", errout.str());
     }
 
     void returnLocalVariable5() { // cast