From 8025a29171cd1c650bcc11fa2c2806a2724bce73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludvig=20Gunne=20Lindstr=C3=B6m?=
 <ludviggunnelindstrom@gmail.com>
Date: Mon, 13 Jul 2026 14:38:47 +0200
Subject: [PATCH 1/3] add test

---
 test/testfunctions.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/testfunctions.cpp b/test/testfunctions.cpp
index 788ff7a0d14..b5ed2871a73 100644
--- a/test/testfunctions.cpp
+++ b/test/testfunctions.cpp
@@ -86,6 +86,7 @@ class TestFunctions : public TestFixture {
         TEST_CASE(checkMissingReturn5);
         TEST_CASE(checkMissingReturn6); // #13180
         TEST_CASE(checkMissingReturn7); // #14370 - FN try/catch
+        TEST_CASE(checkMissingReturn8);
         TEST_CASE(checkMissingReturnStdInt); // #14482 - FN std::int32_t
 
         // std::move for locar variable
@@ -1927,6 +1928,13 @@ class TestFunctions : public TestFixture {
         ASSERT_EQUALS("[test.cpp:3:19]: (error) Found an exit path from function with non-void return type that has missing return statement [missingReturn]\n", errout_str());
     }
 
+    void checkMissingReturn8() {
+        check("boost::asio::awaitable<void> test() {\n"
+              "        co_return;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void checkMissingReturnStdInt() {// #14482 - FN
         check("std::int32_t f() {}\n");
         ASSERT_EQUALS("[test.cpp:1:19]: (error) Found an exit path from function with non-void return type that has missing return statement [missingReturn]\n", errout_str());

From 07e0b49dbaf2620381c1cb25c89b2d57a57602b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludvig=20Gunne=20Lindstr=C3=B6m?=
 <ludviggunnelindstrom@gmail.com>
Date: Mon, 13 Jul 2026 14:35:34 +0200
Subject: [PATCH 2/3] fix

---
 lib/checkfunctions.cpp |  2 ++
 lib/symboldatabase.cpp | 12 ++++++++++++
 lib/symboldatabase.h   |  1 +
 3 files changed, 15 insertions(+)

diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index 23db248816d..2490dbd02b7 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -329,6 +329,8 @@ void CheckFunctionsImpl::checkMissingReturn()
             continue;
         if (Function::returnsVoid(function, true))
             continue;
+        if (Function::isCoroutine(function))
+            continue;
         const Token *errorToken = checkMissingReturnScope(scope->bodyEnd, mSettings.library);
         if (errorToken)
             missingReturnError(errorToken);
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index b82a3f790b0..5a9f68988a4 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -3407,6 +3407,18 @@ bool Function::returnsVoid(const Function* function, bool unknown)
     });
 }
 
+bool Function::isCoroutine(const Function* function)
+{
+    if (!function->functionScope)
+        return false;
+    const Scope *scope = function->functionScope;
+    for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
+        if (Token::Match(tok, "co_return|co_await|co_yield"))
+            return true;
+    }
+    return false;
+}
+
 std::vector<const Token*> Function::findReturns(const Function* f)
 {
     std::vector<const Token*> result;
diff --git a/lib/symboldatabase.h b/lib/symboldatabase.h
index 166f228ad99..f1fe3464452 100644
--- a/lib/symboldatabase.h
+++ b/lib/symboldatabase.h
@@ -945,6 +945,7 @@ class CPPCHECKLIB Function {
     static bool returnsStandardType(const Function* function, bool unknown = false);
 
     static bool returnsVoid(const Function* function, bool unknown = false);
+    static bool isCoroutine(const Function* function);
 
     static std::vector<const Token*> findReturns(const Function* f);
 

From b496ae896b45edc51c3ce8c7ea62960523a3147c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludvig=20Gunne=20Lindstr=C3=B6m?=
 <ludviggunnelindstrom@gmail.com>
Date: Mon, 13 Jul 2026 15:33:40 +0200
Subject: [PATCH 3/3] add language/standard check

---
 lib/checkfunctions.cpp | 2 +-
 lib/symboldatabase.cpp | 4 +++-
 lib/symboldatabase.h   | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index 2490dbd02b7..1edfdfab6ac 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -329,7 +329,7 @@ void CheckFunctionsImpl::checkMissingReturn()
             continue;
         if (Function::returnsVoid(function, true))
             continue;
-        if (Function::isCoroutine(function))
+        if (Function::isCoroutine(function, mSettings.standards, *mTokenizer))
             continue;
         const Token *errorToken = checkMissingReturnScope(scope->bodyEnd, mSettings.library);
         if (errorToken)
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 5a9f68988a4..89f70191e92 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -3407,8 +3407,10 @@ bool Function::returnsVoid(const Function* function, bool unknown)
     });
 }
 
-bool Function::isCoroutine(const Function* function)
+bool Function::isCoroutine(const Function* function, const Standards &standards, const Tokenizer &tokens)
 {
+    if (!tokens.isCPP() || standards.cpp < Standards::CPP20)
+        return false;
     if (!function->functionScope)
         return false;
     const Scope *scope = function->functionScope;
diff --git a/lib/symboldatabase.h b/lib/symboldatabase.h
index f1fe3464452..7d52d0bfb32 100644
--- a/lib/symboldatabase.h
+++ b/lib/symboldatabase.h
@@ -945,7 +945,7 @@ class CPPCHECKLIB Function {
     static bool returnsStandardType(const Function* function, bool unknown = false);
 
     static bool returnsVoid(const Function* function, bool unknown = false);
-    static bool isCoroutine(const Function* function);
+    static bool isCoroutine(const Function* function, const Standards &standards, const Tokenizer &tokens);
 
     static std::vector<const Token*> findReturns(const Function* f);