From 3f7093004a1173f6afdb5380cf28fe05ac50d209 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 30 Oct 2021 19:34:46 +0200
Subject: [PATCH] Fixed #10485 (FP unusedStructMember for array size)

---
 lib/checkunusedvar.cpp | 19 +++++++++++--------
 test/testunusedvar.cpp |  9 +++++++++
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index 5f77a6534..ad422db41 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -1456,14 +1456,17 @@ void CheckUnusedVar::checkStructMemberUsage()
                 continue;
 
             // Check if the struct member variable is used anywhere in the file
-            std::string tmp(". " + var.name());
-            if (Token::findsimplematch(mTokenizer->tokens(), tmp.c_str(), tmp.size()))
-                continue;
-            tmp = (":: " + var.name());
-            if (Token::findsimplematch(mTokenizer->tokens(), tmp.c_str(), tmp.size()))
-                continue;
-
-            unusedStructMemberError(var.nameToken(), scope.className, var.name(), scope.type == Scope::eUnion);
+            bool use = false;
+            for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
+                if (tok->variable() != &var)
+                    continue;
+                if (tok != var.nameToken()) {
+                    use = true;
+                    break;
+                }
+            }
+            if (!use)
+                unusedStructMemberError(var.nameToken(), scope.className, var.name(), scope.type == Scope::eUnion);
         }
     }
 }
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 5fb60f986..51888a3b0 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -60,6 +60,7 @@ private:
         TEST_CASE(structmember14); // #6508 - (struct x){1,2,..}
         TEST_CASE(structmember15); // #3088 - #pragma pack(1)
         TEST_CASE(structmember_sizeof);
+        TEST_CASE(structmember16); // #10485
 
         TEST_CASE(localvar1);
         TEST_CASE(localvar2);
@@ -1563,6 +1564,14 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void structmember16() {
+        checkStructMemberUsage("struct S {\n"
+                               "  static const int N = 128;\n" // <- used
+                               "  char E[N];\n" // <- not used
+                               "};\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) struct member 'S::E' is never used.\n", errout.str());
+    }
+
     void functionVariableUsage(const char code[], const char filename[]="test.cpp") {
         // Clear the error buffer..
         errout.str("");