From bb327be8e80a387351464687ea24e037bb10fa9b Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Sat, 18 Dec 2021 22:55:52 +0100
Subject: [PATCH] Fix #10591 FP unusedStructMember with value-initialized
 struct and typedef (#3643)

---
 lib/tokenize.cpp       |  3 ++-
 test/testunusedvar.cpp | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index fb85983fd..8d76d3f63 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3952,7 +3952,8 @@ void Tokenizer::setVarIdPass1()
                     } else
                         decl = false;
                 } else if (isCPP() && Token::Match(prev2, "%type% {") && Token::simpleMatch(tok2->link(), "} ;")) { // C++11 initialization style
-                    if (Token::Match(prev2, "do|try|else") || Token::Match(prev2->tokAt(-2), "struct|class|:"))
+                    if (tok2->link() != tok2->next() && // add value-initialized variable T x{};
+                        (Token::Match(prev2, "do|try|else") || Token::Match(prev2->tokAt(-2), "struct|class|:")))
                         continue;
                 } else
                     decl = false;
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 64642c284..d0bf1d0af 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -61,6 +61,7 @@ private:
         TEST_CASE(structmember15); // #3088 - #pragma pack(1)
         TEST_CASE(structmember_sizeof);
         TEST_CASE(structmember16); // #10485
+        TEST_CASE(structmember17); // #10591
 
         TEST_CASE(localvar1);
         TEST_CASE(localvar2);
@@ -1574,6 +1575,24 @@ private:
         ASSERT_EQUALS("[test.cpp:3]: (style) struct member 'S::E' is never used.\n", errout.str());
     }
 
+    void structmember17() { // #10591
+        checkStructMemberUsage("struct tagT { int i; };\n"
+                               "void f() {\n"
+                               "    struct tagT t{};\n"
+                               "    t.i = 0;\n" // <- used
+                               "    g(t);\n"
+                               "};\n");
+        ASSERT_EQUALS("", errout.str());
+
+        checkStructMemberUsage("typedef struct tagT { int i; } typeT;\n"
+                               "void f() {\n"
+                               "    struct typeT t{};\n"
+                               "    t.i = 0;\n" // <- used
+                               "    g(t);\n"
+                               "};\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void functionVariableUsage_(const char* file, int line, const char code[], const char filename[] = "test.cpp") {
         // Clear the error buffer..
         errout.str("");