cxxmodules: generate synthetic targets as an initial pass

We need to be able to construct BMIs that will be usable from the client
modules for the target importing the module, so create BMI-only
compilation rules for `IMPORTED` targets to create these BMIs.

1 files changed, 180 insertions, 0 deletions

diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 7d4b497..ace93e8 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -1748,6 +1748,186 @@ cmBTStringRange cmTarget::GetLinkInterfaceDirectExcludeEntries() const
   return cmMakeRange(this->impl->InterfaceLinkLibrariesDirectExclude.Entries);
 }
 
+void cmTarget::CopyPolicyStatuses(cmTarget const* tgt)
+{
+  // Normal targets cannot be the target of a copy.
+  assert(!this->IsNormal());
+  // Imported targets cannot be the target of a copy.
+  assert(!this->IsImported());
+  // Only imported targets can be the source of a copy.
+  assert(tgt->IsImported());
+
+  this->impl->PolicyMap = tgt->impl->PolicyMap;
+}
+
+void cmTarget::CopyImportedCxxModulesEntries(cmTarget const* tgt)
+{
+  // Normal targets cannot be the target of a copy.
+  assert(!this->IsNormal());
+  // Imported targets cannot be the target of a copy.
+  assert(!this->IsImported());
+  // Only imported targets can be the source of a copy.
+  assert(tgt->IsImported());
+
+  this->impl->IncludeDirectories.Entries.clear();
+  this->impl->IncludeDirectories.CopyFromEntries(
+    cmMakeRange(tgt->impl->ImportedCxxModulesIncludeDirectories.Entries));
+  this->impl->CompileDefinitions.Entries.clear();
+  this->impl->CompileDefinitions.CopyFromEntries(
+    cmMakeRange(tgt->impl->ImportedCxxModulesCompileDefinitions.Entries));
+  this->impl->CompileFeatures.Entries.clear();
+  this->impl->CompileFeatures.CopyFromEntries(
+    cmMakeRange(tgt->impl->ImportedCxxModulesCompileFeatures.Entries));
+  this->impl->CompileOptions.Entries.clear();
+  this->impl->CompileOptions.CopyFromEntries(
+    cmMakeRange(tgt->impl->ImportedCxxModulesCompileOptions.Entries));
+  this->impl->LinkLibraries.Entries.clear();
+  this->impl->LinkLibraries.CopyFromEntries(
+    cmMakeRange(tgt->impl->LinkLibraries.Entries));
+
+  // Copy the C++ module fileset entries from `tgt`'s `INTERFACE` to this
+  // target's `PRIVATE`.
+  this->impl->CxxModulesFileSets.SelfEntries.Entries.clear();
+  this->impl->CxxModulesFileSets.SelfEntries.Entries =
+    tgt->impl->CxxModulesFileSets.InterfaceEntries.Entries;
+}
+
+void cmTarget::CopyImportedCxxModulesProperties(cmTarget const* tgt)
+{
+  // Normal targets cannot be the target of a copy.
+  assert(!this->IsNormal());
+  // Imported targets cannot be the target of a copy.
+  assert(!this->IsImported());
+  // Only imported targets can be the source of a copy.
+  assert(tgt->IsImported());
+
+  // The list of properties that are relevant here include:
+  // - compilation-specific properties for any language or platform
+  // - compilation-specific properties for C++
+  // - build graph-specific properties that affect compilation
+  // - IDE metadata properties
+  // - static analysis properties
+
+  static const std::string propertiesToCopy[] = {
+    // Compilation properties
+    "DEFINE_SYMBOL",
+    "DEPRECATION",
+    "NO_SYSTEM_FROM_IMPORTED",
+    "POSITION_INDEPENDENT_CODE",
+    "VISIBILITY_INLINES_HIDDEN",
+    // -- Platforms
+    // ---- Android
+    "ANDROID_API",
+    "ANDROID_API_MIN",
+    "ANDROID_ARCH",
+    "ANDROID_STL_TYPE",
+    // ---- macOS
+    "OSX_ARCHITECTURES",
+    // ---- Windows
+    "MSVC_DEBUG_INFORMATION_FORMAT",
+    "MSVC_RUNTIME_LIBRARY",
+    "VS_PLATFORM_TOOLSET",
+    // ---- OpenWatcom
+    "WATCOM_RUNTIME_LIBRARY",
+    // -- Language
+    // ---- C++
+    "CXX_COMPILER_LAUNCHER",
+    "CXX_STANDARD",
+    "CXX_STANDARD_REQUIRED",
+    "CXX_EXTENSIONS",
+    "CXX_VISIBILITY_PRESET",
+
+    // Static analysis
+    "CXX_CLANG_TIDY",
+    "CXX_CLANG_TIDY_EXPORT_FIXES_DIR",
+    "CXX_CPPLINT",
+    "CXX_CPPCHECK",
+    "CXX_INCLUDE_WHAT_YOU_USE",
+
+    // Build graph properties
+    "EXCLUDE_FROM_ALL",
+    "EXCLUDE_FROM_DEFAULT_BUILD",
+    "OPTIMIZE_DEPENDENCIES",
+    // -- Ninja
+    "JOB_POOL_COMPILE",
+    // -- Visual Studio
+    "VS_NO_COMPILE_BATCHING",
+    "VS_PROJECT_IMPORT",
+
+    // Metadata
+    "EchoString",
+    "EXPORT_COMPILE_COMMANDS",
+    "FOLDER",
+    "LABELS",
+    "PROJECT_LABEL",
+    "SYSTEM",
+  };
+
+  auto copyProperty = [this, tgt](std::string const& prop) -> cmValue {
+    cmValue value = tgt->GetProperty(prop);
+    // Always set the property; it may have been explicitly unset.
+    this->SetProperty(prop, value);
+    return value;
+  };
+
+  for (auto const& prop : propertiesToCopy) {
+    copyProperty(prop);
+  }
+
+  static const cm::static_string_view perConfigPropertiesToCopy[] = {
+    "EXCLUDE_FROM_DEFAULT_BUILD_"_s,
+    "IMPORTED_CXX_MODULES_"_s,
+    "MAP_IMPORTED_CONFIG_"_s,
+    "OSX_ARCHITECTURES_"_s,
+  };
+
+  std::vector<std::string> configNames =
+    this->impl->Makefile->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
+  for (std::string const& configName : configNames) {
+    std::string configUpper = cmSystemTools::UpperCase(configName);
+    for (auto const& perConfigProp : perConfigPropertiesToCopy) {
+      copyProperty(cmStrCat(perConfigProp, configUpper));
+    }
+  }
+
+  if (this->GetGlobalGenerator()->IsXcode()) {
+    cmValue xcodeGenerateScheme = copyProperty("XCODE_GENERATE_SCHEME");
+
+    // TODO: Make sure these show up on the imported target in the first place
+    // XCODE_ATTRIBUTE_???
+
+    if (xcodeGenerateScheme.IsOn()) {
+#ifdef __APPLE__
+      static const std::string xcodeSchemePropertiesToCopy[] = {
+        // FIXME: Do all of these apply? Do they matter?
+        "XCODE_SCHEME_ADDRESS_SANITIZER",
+        "XCODE_SCHEME_ADDRESS_SANITIZER_USE_AFTER_RETURN",
+        "XCODE_SCHEME_DISABLE_MAIN_THREAD_CHECKER",
+        "XCODE_SCHEME_DYNAMIC_LIBRARY_LOADS",
+        "XCODE_SCHEME_DYNAMIC_LINKER_API_USAGE",
+        "XCODE_SCHEME_ENABLE_GPU_API_VALIDATION",
+        "XCODE_SCHEME_ENABLE_GPU_SHADER_VALIDATION",
+        "XCODE_SCHEME_GUARD_MALLOC",
+        "XCODE_SCHEME_LAUNCH_CONFIGURATION",
+        "XCODE_SCHEME_MAIN_THREAD_CHECKER_STOP",
+        "XCODE_SCHEME_MALLOC_GUARD_EDGES",
+        "XCODE_SCHEME_MALLOC_SCRIBBLE",
+        "XCODE_SCHEME_MALLOC_STACK",
+        "XCODE_SCHEME_THREAD_SANITIZER",
+        "XCODE_SCHEME_THREAD_SANITIZER_STOP",
+        "XCODE_SCHEME_UNDEFINED_BEHAVIOUR_SANITIZER",
+        "XCODE_SCHEME_UNDEFINED_BEHAVIOUR_SANITIZER_STOP",
+        "XCODE_SCHEME_ZOMBIE_OBJECTS",
+      };
+
+      for (auto const& xcodeProperty : xcodeSchemePropertiesToCopy) {
+        copyProperty(xcodeProperty);
+      }
+#endif
+    }
+  }
+}
+
 cmBTStringRange cmTarget::GetHeaderSetsEntries() const
 {
   return cmMakeRange(this->impl->HeadersFileSets.SelfEntries.Entries);