From 385c9d341d422e245547227a5daf33c13224da08 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <danielm77@spray.se>
Date: Sun, 26 Feb 2012 08:29:02 +0100
Subject: [PATCH] Fixed #3633 (False positive: struct array not assigned a
 value)

---
 lib/checkunusedvar.cpp | 19 +++++++++++++++++--
 test/testunusedvar.cpp | 10 ++++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index fb5996181..a0138a3c9 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -579,6 +579,21 @@ static const Token * skipBrackets(const Token *tok)
 }
 
 
+// Skip [ .. ] . x
+static const Token * skipBracketsAndMembers(const Token *tok)
+{
+    while (tok) {
+        if (tok->str() == "[")
+            tok = tok->link()->next();
+        else if (Token::Match(tok, ". %var%"))
+            tok = tok->tokAt(2);
+        else
+            break;
+    }
+    return tok;
+}
+
+
 //---------------------------------------------------------------------------
 // Usage of function variables
 //---------------------------------------------------------------------------
@@ -804,7 +819,7 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
                 }
             }
 
-            const Token *equal = skipBrackets(tok->next());
+            const Token * const equal = skipBracketsAndMembers(tok->next());
 
             // checked for chained assignments
             if (tok != start && equal && equal->str() == "=") {
@@ -818,7 +833,7 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
         }
 
         // assignment
-        else if (Token::Match(tok, "%var% [") && Token::simpleMatch(skipBrackets(tok->next()), "=")) {
+        else if (Token::Match(tok, "%var% [") && Token::simpleMatch(skipBracketsAndMembers(tok->next()), "=")) {
             unsigned int varid = tok->varId();
             const Variables::VariableUsage *var = variables.find(varid);
 
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 433dbbfc3..bc311078c 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -117,6 +117,7 @@ private:
         TEST_CASE(localvarStruct4); // Ticket #31: sigsegv on incomplete struct
         TEST_CASE(localvarStruct5);
         TEST_CASE(localvarStruct6);
+        TEST_CASE(localvarStructArray);
 
         TEST_CASE(localvarOp);          // Usage with arithmetic operators
         TEST_CASE(localvarInvert);      // Usage with inverted variable
@@ -2462,6 +2463,15 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void localvarStructArray() {
+        // #3633 - detect that struct array is assigned a value
+        functionVariableUsage("void f() {\n"
+                              "    struct X x[10];\n"
+                              "    x[0].a = 0;\n"
+                              "}");
+        ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'x' is assigned a value that is never used\n", errout.str());
+    }
+
     void localvarOp() {
         const char op[] = "+-*/%&|^";
         for (const char *p = op; *p; ++p) {