Workaround Apple linker deduplication bug

Author: MungoG

.github/workflows/ci.yml

@@ -158,6 +158,18 @@ jobs:
           # OSX compilers
           #
 
+          - compiler: "apple-clang"
+            version: "*"
+            cxx: "clang++"
+            cc: "clang"
+            runs-on: "macos-26"
+            b2-toolset: "clang"
+            is-latest: true
+            name: "Apple-Clang (macOS 26)"
+            shared: true
+            build-type: "Release"
+            build-cmake: true
+
           - compiler: "apple-clang"
             version: "*"
             cxx: "clang++"
@@ -182,6 +194,17 @@ jobs:
             build-type: "RelWithDebInfo"
             asan: true
 
+          - compiler: "apple-clang"
+            version: "*"
+            cxx: "clang++"
+            cc: "clang"
+            runs-on: "macos-15"
+            b2-toolset: "clang"
+            name: "Apple-Clang (macOS 15)"
+            shared: false
+            build-type: "Release"
+            build-cmake: true
+
           - compiler: "apple-clang"
             version: "*"
             cxx: "clang++"

include/boost/http_proto/server/basic_router.hpp

@@ -1009,6 +1009,15 @@ class basic_router : public /*detail::*/any_router
             }
             catch(E const& ex)
             {
+#ifdef __APPLE__
+                // The Apple linker has a bug whereby it can erroneously
+                // deduplicate functions with identical codegen even though the
+                // unwind tables are different. Here we force different codegen
+                // depending on the type of E.
+                static volatile int apple_linker_bug_workaround_ = 0;
+                if(apple_linker_bug_workaround_)
+                    throw ex;
+#endif // APPLE
                 set_resume u(p_);
                 // VFALCO What if h throws?
                 auto rv = h(p, ex);

test/unit/CMakeLists.txt

@@ -7,7 +7,9 @@
 # Official repository: https://github.com/cppalliance/http_proto
 #
 
-add_subdirectory(../../../url/extra/test_suite test_suite)
+if (NOT TARGET boost_url_test_suite)
+    add_subdirectory(../../../url/extra/test_suite test_suite)
+endif()
 
 file(GLOB_RECURSE PFILES CONFIGURE_DEPENDS *.cpp *.hpp)
 list(APPEND PFILES