Ninja: support short object directories

Help/release/dev/short-object-names.rst

@@ -4,4 +4,7 @@ short-object-names
 * There is now the :variable:`CMAKE_INTERMEDIATE_DIR_STRATEGY` variable (and
   associated environment variable :envvar:`CMAKE_INTERMEDIATE_DIR_STRATEGY`)
   that may be used to change the strategy used to name intermediate
-  directories used for object files (and other associated target metadata).
+  directories used for object files (and other associated target metadata). It
+  is supported for the following generators:
+
+  - :ref:`Ninja Generators`

Source/cmGlobalNinjaGenerator.cxx

@@ -1048,6 +1048,11 @@ bool cmGlobalNinjaGenerator::HasRule(std::string const& name)
 
 // Private virtual overrides
 
+bool cmGlobalNinjaGenerator::SupportsShortObjectNames() const
+{
+  return true;
+}
+
 void cmGlobalNinjaGenerator::ComputeTargetObjectDirectory(
   cmGeneratorTarget* gt) const
 {
@@ -2276,7 +2281,7 @@ void cmGlobalNinjaGenerator::StripNinjaOutputPathPrefixAsSuffix(
 /*
 
 We use the following approach to support Fortran.  Each target already
-has a <target>.dir/ directory used to hold intermediate files for CMake.
+has an intermediate directory used to hold intermediate files for CMake.
 For each target, a FortranDependInfo.json file is generated by CMake with
 information about include directories, module directories, and the locations
 the per-target directories for target dependencies.

Source/cmGlobalNinjaGenerator.h

@@ -391,6 +391,7 @@ public:
   void AddTargetAlias(std::string const& alias, cmGeneratorTarget* target,
                       std::string const& config);
 
+  bool SupportsShortObjectNames() const override;
   void ComputeTargetObjectDirectory(cmGeneratorTarget* gt) const override;
 
   // Ninja generator uses 'deps' and 'msvc_deps_prefix' introduced in 1.3

Source/cmLocalNinjaGenerator.cxx

@@ -163,6 +163,15 @@ void cmLocalNinjaGenerator::Generate()
   }
 }
 
+std::string cmLocalNinjaGenerator::GetObjectOutputRoot() const
+{
+  if (this->UseShortObjectNames()) {
+    return cmStrCat(this->GetBinaryDirectory(), '/',
+                    this->GetGlobalGenerator()->GetShortBinaryOutputDir());
+  }
+  return cmStrCat(this->GetCurrentBinaryDirectory(), "/CMakeFiles");
+}
+
 // Non-virtual public methods.
 
 cmGlobalNinjaGenerator const* cmLocalNinjaGenerator::GetGlobalNinjaGenerator()

Source/cmLocalNinjaGenerator.h

@@ -62,6 +62,7 @@ public:
   {
     return this->HomeRelativeOutputPath;
   }
+  std::string GetObjectOutputRoot() const override;
 
   std::string BuildCommandLine(
     std::vector<std::string> const& cmdLines, std::string const& outputConfig,

Source/cmNinjaTargetGenerator.cxx

@@ -1414,6 +1414,12 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatement(
   vars["DEFINES"] = this->ComputeDefines(source, language, config);
   vars["INCLUDES"] = this->ComputeIncludes(source, language, config);
   vars["CONFIG"] = config;
+  if (this->GetGeneratorTarget()->GetUseShortObjectNames()) {
+    vars.emplace(
+      "description",
+      cmStrCat("Compiling object ", objectFileName, " from source ",
+               this->GetLocalGenerator()->GetRelativeSourceFileName(*source)));
+  }
 
   auto compilerLauncher = this->GetCompilerLauncher(language, config);
 

Tests/RunCMake/Ninja/LooseObjectDepends.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 
 add_custom_command(

Tests/RunCMake/Ninja/LooseObjectDependsShort.cmake

@@ -0,0 +1,27 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY SHORT CACHE STRING "" FORCE)
+
+enable_language(C)
+
+add_custom_command(
+  OUTPUT  "${CMAKE_CURRENT_BINARY_DIR}/command.h"
+  COMMAND "${CMAKE_COMMAND}" -E touch
+          "${CMAKE_CURRENT_BINARY_DIR}/command.h"
+          COMMENT "Creating command.h")
+add_custom_target(create-command.h
+  DEPENDS
+    "${CMAKE_CURRENT_BINARY_DIR}/command.h")
+
+add_custom_target(create-target.h
+  BYPRODUCTS  "${CMAKE_CURRENT_BINARY_DIR}/target.h"
+  COMMAND "${CMAKE_COMMAND}" -E touch
+          "${CMAKE_CURRENT_BINARY_DIR}/target.h"
+  COMMENT "Creating target.h")
+
+add_library(dep SHARED dep.c)
+add_dependencies(dep create-command.h create-target.h)
+target_include_directories(dep
+  PUBLIC
+    "${CMAKE_CURRENT_BINARY_DIR}")
+
+add_library(top top.c)
+target_link_libraries(top PRIVATE dep)

Tests/RunCMake/Ninja/RunCMakeTest.cmake

@@ -83,6 +83,16 @@ function(run_VerboseBuild)
 endfunction()
 run_VerboseBuild()
 
+function(run_VerboseBuildShort)
+  run_cmake(VerboseBuildShort)
+  set(RunCMake_TEST_NO_CLEAN 1)
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/VerboseBuildShort-build)
+  set(RunCMake_TEST_OUTPUT_MERGE 1)
+  run_cmake_command(VerboseBuildShort-build ${CMAKE_COMMAND} --build . -v --clean-first)
+  run_cmake_command(VerboseBuildShort-nowork ${CMAKE_COMMAND} --build . --verbose)
+endfunction()
+run_VerboseBuildShort()
+
 function(run_CMP0058 case)
   # Use a single build tree for a few tests without cleaning.
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/CMP0058-${case}-build)
@@ -195,6 +205,23 @@ function (run_LooseObjectDepends)
 endfunction ()
 run_LooseObjectDepends()
 
+function (run_LooseObjectDependsShort)
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/LooseObjectDependsShort-build)
+  run_cmake(LooseObjectDependsShort)
+  run_ninja("${RunCMake_TEST_BINARY_DIR}" ".o/e86fd702/b1363cd8${CMAKE_C_OUTPUT_EXTENSION}")
+  if (EXISTS "${RunCMake_TEST_BINARY_DIR}/${CMAKE_SHARED_LIBRARY_PREFIX}dep${CMAKE_SHARED_LIBRARY_SUFFIX}")
+    message(FATAL_ERROR
+      "The `dep` library was created when requesting an object file to be "
+      "built; this should no longer be necessary.")
+  endif ()
+  if (EXISTS "${RunCMake_TEST_BINARY_DIR}/.o/600bd702/d56215${CMAKE_C_OUTPUT_EXTENSION}")
+    message(FATAL_ERROR
+      "The `dep.c` object file was created when requesting an object file to "
+      "be built; this should no longer be necessary.")
+  endif ()
+endfunction ()
+run_LooseObjectDependsShort()
+
 function (run_CustomCommandExplictDepends)
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/CustomCommandExplicitDepends-build)
   run_cmake(CustomCommandExplicitDepends)
@@ -425,3 +452,5 @@ if(CMake_TEST_Qt_version)
 endif()
 
 run_cmake(LINK_OPTIONSWithNewlines)
+
+run_cmake(StaticLibShort)

Tests/RunCMake/Ninja/StaticLibShort-build-stdout.txt

@@ -0,0 +1 @@
+.*.o.75d5d702.cf59cf\.o.*

Tests/RunCMake/Ninja/StaticLibShort.cmake

@@ -0,0 +1,7 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY SHORT CACHE STRING "" FORCE)
+
+enable_language(C)
+add_library(greeting STATIC greeting.c)
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+add_executable(hello hello_with_greeting.c)
+target_link_libraries(hello greeting)

Tests/RunCMake/Ninja/VerboseBuild.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 add_executable(hello hello.c)
 target_compile_definitions(hello PRIVATE "DEFINE_FOR_VERBOSE_DETECTION")

Tests/RunCMake/Ninja/VerboseBuildShort-build-stdout.txt

@@ -0,0 +1 @@
+DEFINE_FOR_VERBOSE_DETECTION.*75d5d702.4efa03e1.o

Tests/RunCMake/Ninja/VerboseBuildShort-nowork-stdout.txt

@@ -0,0 +1 @@
+ninja: no work to do

Tests/RunCMake/Ninja/VerboseBuildShort.cmake

@@ -0,0 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY SHORT CACHE STRING "" FORCE)
+
+enable_language(C)
+add_executable(hello hello.c)
+target_compile_definitions(hello PRIVATE "DEFINE_FOR_VERBOSE_DETECTION")

Tests/RunCMake/NinjaMultiConfig/CompileCommands.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 
 add_executable(exe main.c)

Tests/RunCMake/NinjaMultiConfig/CustomCommandOutputGenex.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 
 add_executable(echo echo.c)

Tests/RunCMake/NinjaMultiConfig/CustomCommandsAndTargets.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 
 file(REMOVE "${CMAKE_BINARY_DIR}/target_files_custom.cmake")

Tests/RunCMake/NinjaMultiConfig/ExcludeFromAll.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 
 set(CMAKE_CONFIGURATION_TYPES "Release;Debug" CACHE STRING "")

Tests/RunCMake/NinjaMultiConfig/PostfixAndLocation.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(C)
 
 set(CMAKE_DEBUG_POSTFIX "_debug")

Tests/RunCMake/NinjaPrivateDeps/CMP0154-common.cmake

@@ -1,3 +1,5 @@
+set(CMAKE_INTERMEDIATE_DIR_STRATEGY FULL CACHE STRING "" FORCE)
+
 enable_language(CXX)
 
 function(copy_file file dest)

Tests/RunCMake/ObjectLibrary/RunCMakeTest.cmake

@@ -91,6 +91,6 @@ function(run_Dependencies suffix)
 endfunction()
 
 run_Dependencies("")
-if (CMAKE_GENERATOR MATCHES "NONE")
+if (CMAKE_GENERATOR MATCHES "Ninja")
   run_Dependencies(Short)
 endif ()

Tests/RunCMake/PrecompileHeaders/RunCMakeTest.cmake

@@ -18,7 +18,7 @@ endfunction()
 run_cmake(DisabledPch)
 run_cmake(PchDebugGenex)
 run_test(PchInterface)
-if (CMAKE_GENERATOR MATCHES "NONE")
+if (CMAKE_GENERATOR MATCHES "Ninja")
   run_test(PchInterfaceShort)
 endif ()
 run_test(PchInterfaceUnity)

Tests/RunCMake/UnityBuild/RunCMakeTest.cmake

@@ -72,6 +72,6 @@ endfunction()
 run_test(unitybuild_runtest)
 run_test(unitybuild_object_library)
 
-if (CMAKE_GENERATOR MATCHES "NONE")
+if (CMAKE_GENERATOR MATCHES "Ninja")
   run_build(unitybuild_cxx_short)
 endif ()