install(EXPORT): Use UNWIND_INCLUDE in exported find_dependency()

Source/cmExportCMakeConfigGenerator.cxx

@@ -451,16 +451,27 @@ void cmExportCMakeConfigGenerator::GenerateFindDependencyCalls(
       return lhs.second.FindPackageIndex < rhs.second.FindPackageIndex;
     });
 
+  // Unwinding is only valid in a find_package() context
+  os << "if(DEFINED CMAKE_FIND_PACKAGE_NAME)\n"
+     << "  set(_cmake_unwind_arg UNWIND_INCLUDE)\n"
+     << "endif()\n\n";
+
   for (auto const& it : packageDependenciesSorted) {
     if (it.second.Enabled == cmExportSet::PackageDependencyExportEnabled::On) {
-      os << "find_dependency(" << it.first;
+      os << "__find_dependency_no_return(" << it.first;
       for (auto const& arg : it.second.ExtraArguments) {
         os << ' ' << cmOutputConverter::EscapeForCMake(arg);
       }
-      os << ")\n";
+      os << " ${_cmake_unwind_arg})\n";
+      os << "if(NOT " << it.first << "_FOUND)\n"
+         << "  unset(_cmake_unwind_arg)\n"
+         << "  cmake_policy(POP)\n"
+         << "  return()\n"
+         << "endif()\n\n";
     }
   }
-  os << "\n\n";
+
+  os << "unset(_cmake_unwind_arg)\n\n\n";
 }
 
 void cmExportCMakeConfigGenerator::GenerateMissingTargetsCheckCode(

Tests/RunCMake/export/FindDependencyExport-check.cmake

@@ -1,35 +1,35 @@
 file(READ "${RunCMake_TEST_BINARY_DIR}/mytargets.cmake" mytargets)
-if("${mytargets}" MATCHES "find_dependency\\(P1")
+if("${mytargets}" MATCHES "__find_dependency_no_return\\(P1")
   string(APPEND RunCMake_TEST_FAILED "P1 dependency should not be exported but it is\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P2 \"VERSION\" \"1\\.0\"\\)")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P2")
   string(APPEND RunCMake_TEST_FAILED "P2 dependency should be exported but it is not\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P3\\)")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P3")
   string(APPEND RunCMake_TEST_FAILED "P3 dependency should be exported but it is not\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P4\\)")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P4")
   string(APPEND RunCMake_TEST_FAILED "P4 dependency should be exported but it is not\n")
 endif()
-if("${mytargets}" MATCHES "find_dependency\\(P5")
+if("${mytargets}" MATCHES "__find_dependency_no_return\\(P5")
   string(APPEND RunCMake_TEST_FAILED "P5 dependency should not be exported but it is\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P6\\)")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P6")
   string(APPEND RunCMake_TEST_FAILED "P6 dependency should be exported but it is not\n")
 endif()
-if("${mytargets}" MATCHES "find_dependency\\(P7")
+if("${mytargets}" MATCHES "__find_dependency_no_return\\(P7")
   string(APPEND RunCMake_TEST_FAILED "P7 dependency should not be exported but it is\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P3[^
-]*\\)
-find_dependency\\(P2[^
-]*\\)
-find_dependency\\(P8[^
-]*\\)
-find_dependency\\(P6[^
-]*\\)
-find_dependency\\(P9[^
-]*\\)
-find_dependency\\(P4")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P3[^
+]*\\)(.*)
+__find_dependency_no_return\\(P2[^
+]*\\)(.*)
+__find_dependency_no_return\\(P8[^
+]*\\)(.*)
+__find_dependency_no_return\\(P6[^
+]*\\)(.*)
+__find_dependency_no_return\\(P9[^
+]*\\)(.*)
+__find_dependency_no_return\\(P4")
   string(APPEND RunCMake_TEST_FAILED "Dependencies are not in the correct order\n")
 endif()

Tests/RunCMake/export/FindDependencyExportStatic-check.cmake

@@ -1,13 +1,13 @@
 file(READ "${RunCMake_TEST_BINARY_DIR}/mytargets.cmake" mytargets)
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P1")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P1")
   string(APPEND RunCMake_TEST_FAILED "P1 dependency should be exported but it is not\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P2")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P2")
   string(APPEND RunCMake_TEST_FAILED "P2 dependency should be exported but it is not\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P3")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P3")
   string(APPEND RunCMake_TEST_FAILED "P3 dependency should be exported but it is not\n")
 endif()
-if(NOT "${mytargets}" MATCHES "find_dependency\\(P4")
+if(NOT "${mytargets}" MATCHES "__find_dependency_no_return\\(P4")
   string(APPEND RunCMake_TEST_FAILED "P4 dependency should be exported but it is not\n")
 endif()

Tests/RunCMake/install/EXPORT-FindDependencyExport-all-check.cmake

@@ -1,4 +1,15 @@
 file(READ "${RunCMake_TEST_BINARY_DIR}/root-all/lib/cmake/mylib/mylib-targets.cmake" contents)
-if(NOT contents MATCHES "include\\(CMakeFindDependencyMacro\\)\nfind_dependency\\(P2\\)\nfind_dependency\\(P1\\)\n")
-  set(RunCMake_TEST_FAILED "Dependencies were not properly exported")
+
+if(NOT contents MATCHES "__find_dependency_no_return\\(P2")
+  string(APPEND RunCMake_TEST_FAILED "P2 dependency should be exported but it is not\n")
+endif()
+
+if(NOT contents MATCHES "__find_dependency_no_return\\(P1")
+  string(APPEND RunCMake_TEST_FAILED "P1 dependency should be exported but it is not\n")
+endif()
+
+if(NOT contents MATCHES "__find_dependency_no_return\\(P2[^
+]*\\)(.*)
+__find_dependency_no_return\\(P1")
+  string(APPEND RunCMake_TEST_FAILED "Dependencies are not in the correct order\n")
 endif()

Tests/RunCMake/install/EXPORT-Unwind-all-check.cmake

@@ -0,0 +1,8 @@
+cmake_policy(SET CMP0074 NEW)
+set(Unwind_ROOT "${RunCMake_TEST_BINARY_DIR}/root-all")
+
+find_package(Unwind CONFIG QUIET)
+
+if(Unwind_FOUND)
+  set(RunCMake_TEST_FAILED "Unwinding failed, package was reported as found")
+endif()

Tests/RunCMake/install/EXPORT-Unwind-stderr.txt

@@ -0,0 +1,6 @@
+^CMake Warning \(dev\) at EXPORT-Unwind\.cmake:[0-9]+ \(install\):
+  CMake's EXPORT_PACKAGE_DEPENDENCIES support is experimental\.  It is meant
+  only for experimentation and feedback to CMake developers\.
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)
+This warning is for project developers\.  Use -Wno-dev to suppress it\.$

Tests/RunCMake/install/EXPORT-Unwind.cmake

@@ -0,0 +1,12 @@
+set(CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_DEPENDENCIES "1942b4fa-b2c5-4546-9385-83f254070067")
+enable_language(C)
+
+set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
+
+find_package(P1 REQUIRED)
+
+add_library(Unwind INTERFACE)
+target_link_libraries(Unwind INTERFACE lib1)
+install(TARGETS Unwind EXPORT UnwindTargets)
+install(EXPORT UnwindTargets EXPORT_PACKAGE_DEPENDENCIES DESTINATION lib/cmake/Unwind)
+install(FILES cmake/UnwindConfig.cmake DESTINATION lib/cmake/Unwind)

Tests/RunCMake/install/RunCMakeTest.cmake

@@ -189,6 +189,7 @@ run_install_test(FILES-PERMISSIONS)
 run_install_test(TARGETS-RPATH)
 run_install_test(InstallRequiredSystemLibraries)
 run_install_test(EXPORT-FindDependencyExport)
+run_install_test(EXPORT-Unwind)
 
 set(RunCMake_TEST_OPTIONS "-DCMAKE_POLICY_DEFAULT_CMP0087:STRING=NEW")
 run_install_test(SCRIPT)

Tests/RunCMake/install/cmake/UnwindConfig.cmake

@@ -0,0 +1,2 @@
+include(${CMAKE_CURRENT_LIST_DIR}/UnwindTargets.cmake)
+set(Unwind_FOUND true)