Ninja Multi-Config: Fix cross-config codegen target suffix

The target that runs codegen for all cross-configs was named
`codegen:codegen`. Name it `codegen:all` to follow the documented
`<target>:all` convention, as the `all` target already does.

Amends commit 197cb419d1 (add_custom_command: Add CODEGEN support,
2024-05-27, v3.31.0-rc1~394^2).

Source/cmGlobalNinjaGenerator.cxx

@@ -1959,8 +1959,7 @@ void cmGlobalNinjaGenerator::WriteFolderTargets(std::ostream& os)
           build.ExplicitDeps.push_back(
             this->BuildAlias(buildDirCodegenTarget, config));
         }
-        build.Outputs.front() =
-          this->BuildAlias(buildDirCodegenTarget, "codegen");
+        build.Outputs.front() = this->BuildAlias(buildDirCodegenTarget, "all");
         this->WriteBuild(os, build);
       }
     }

Tests/RunCMake/Codegen/RunCMakeTest.cmake

@@ -32,10 +32,27 @@ run_codegen("add-dependencies-not-all")
 block()
   if(RunCMake_GENERATOR_IS_MULTI_CONFIG)
     set(RunCMake_TEST_OPTIONS "-DCMAKE_CONFIGURATION_TYPES=Debug\\;Release")
+    if(RunCMake_GENERATOR STREQUAL "Ninja Multi-Config")
+      list(APPEND RunCMake_TEST_OPTIONS
+        -DCMAKE_CROSS_CONFIGS=all
+        -DCMAKE_DEFAULT_BUILD_TYPE=Release
+      )
+    endif()
   else()
     set(RunCMake_TEST_OPTIONS -DCMAKE_BUILD_TYPE=Debug)
   endif()
   run_codegen("per-config")
+
+  if(RunCMake_GENERATOR STREQUAL "Ninja Multi-Config")
+    set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/per-config-build)
+    set(RunCMake_TEST_NO_CLEAN 1)
+    run_cmake_command(per-config-default-build ${CMAKE_COMMAND} --build . --target codegen)
+    file(REMOVE_RECURSE
+      ${RunCMake_TEST_BINARY_DIR}/Debug
+      ${RunCMake_TEST_BINARY_DIR}/Release
+    )
+    run_cmake_command(per-config-all-build ${CMAKE_COMMAND} --build . --target codegen:all)
+  endif()
 endblock()
 
 # Error handling

Tests/RunCMake/Codegen/per-config-all-build-check.cmake

@@ -0,0 +1,6 @@
+foreach(config IN ITEMS Debug Release)
+  set(filename "${RunCMake_TEST_BINARY_DIR}/${config}/generated.h")
+  if (NOT EXISTS "${filename}")
+    string(APPEND RunCMake_TEST_FAILED "expected file NOT created:\n ${filename}\n")
+  endif()
+endforeach()

Tests/RunCMake/Codegen/per-config-default-build-check.cmake

@@ -0,0 +1,5 @@
+set(filename "${RunCMake_TEST_BINARY_DIR}/Release/generated.h")
+if (NOT EXISTS "${filename}")
+  set(RunCMake_TEST_FAILED "expected file NOT created:\n ${filename}")
+  return()
+endif()