cmGeneratorTarget: Adopt Swift-related methods from the Ninja generator

They will see more use as Swift bugs are fixed in the
Ninja Multi-Config generator.

Source/cmGeneratorTarget.cxx

@@ -5501,3 +5501,45 @@ void cmGeneratorTarget::BuildFileSetInfoCache(std::string const& config) const
 
   per_config.BuiltFileSetCache = true;
 }
+
+std::string cmGeneratorTarget::GetSwiftModuleName() const
+{
+  return this->GetPropertyOrDefault("Swift_MODULE_NAME", this->GetName());
+}
+
+std::string cmGeneratorTarget::GetSwiftModuleFileName() const
+{
+  return this->GetPropertyOrDefault(
+    "Swift_MODULE", this->GetSwiftModuleName() + ".swiftmodule");
+}
+
+std::string cmGeneratorTarget::GetSwiftModuleDirectory(
+  std::string const& config) const
+{
+  std::string moduleDirectory =
+    this->GetPropertyOrDefault("Swift_MODULE_DIRECTORY", "");
+
+  if (moduleDirectory.empty()) {
+    moduleDirectory = this->LocalGenerator->GetCurrentBinaryDirectory();
+    this->LocalGenerator->GetGlobalGenerator()->AppendDirectoryForConfig(
+      "/", config, "", moduleDirectory);
+  }
+
+  return moduleDirectory;
+}
+
+std::string cmGeneratorTarget::GetSwiftModulePath(
+  std::string const& config) const
+{
+  return this->GetSwiftModuleDirectory(config) + "/" +
+    this->GetSwiftModuleFileName();
+}
+
+std::string cmGeneratorTarget::GetPropertyOrDefault(
+  std::string const& property, std::string defaultValue) const
+{
+  if (cmValue name = this->GetProperty(property)) {
+    return *name;
+  }
+  return defaultValue;
+}

Source/cmGeneratorTarget.h

@@ -537,7 +537,27 @@ public:
 
   std::string GetClangTidyExportFixesDirectory(const std::string& lang) const;
 
+  /** Return the swift module name for this target. */
+  std::string GetSwiftModuleName() const;
+
+  /** Return the path of the `.swiftmodule` for this target in
+      the given configuration.  */
+  std::string GetSwiftModulePath(std::string const& config) const;
+
+  /** Return the given property of this target if it exists; otherwise
+      return defaultValue. */
+  std::string GetPropertyOrDefault(std::string const& property,
+                                   std::string defaultValue) const;
+
+  /** Return the name of the `.swiftmodule` file for this target. */
+  std::string GetSwiftModuleFileName() const;
+
 private:
+  /** Return the directory containing Swift module interface
+      descriptions for this target (including its `.swiftmodule`,
+      `.abi.json`, and `.swiftdoc`) in the given configuration.  */
+  std::string GetSwiftModuleDirectory(std::string const& config) const;
+
   using ConfigAndLanguage = std::pair<std::string, std::string>;
   using ConfigAndLanguageToBTStrings =
     std::map<ConfigAndLanguage, std::vector<BT<std::string>>>;

Source/cmNinjaNormalTargetGenerator.cxx

@@ -1078,34 +1078,16 @@ void cmNinjaNormalTargetGenerator::WriteNvidiaDeviceLinkStatement(
   this->WriteNvidiaDeviceLinkRule(usedResponseFile, config);
 }
 
-/// Get the target property if it exists, or return a default
-static std::string GetTargetPropertyOrDefault(cmGeneratorTarget const* target,
-                                              std::string const& property,
-                                              std::string defaultValue)
-{
-  if (cmValue name = target->GetProperty(property)) {
-    return *name;
-  }
-  return defaultValue;
-}
-
-/// Compute the swift module name for target
-static std::string GetSwiftModuleName(cmGeneratorTarget const* target)
-{
-  return GetTargetPropertyOrDefault(target, "Swift_MODULE_NAME",
-                                    target->GetName());
-}
-
-/// Compute the swift module path for the target
+/// Compute the swift module path for the target, sans any config-specific
+/// subdirectory.
 /// The returned path will need to be converted to the generator path
-static std::string GetSwiftModulePath(cmGeneratorTarget const* target)
+static std::string GetSwiftModulePathTree(cmGeneratorTarget const* target)
 {
-  std::string moduleName = GetSwiftModuleName(target);
-  std::string moduleDirectory = GetTargetPropertyOrDefault(
-    target, "Swift_MODULE_DIRECTORY",
+  std::string moduleName = target->GetSwiftModuleName();
+  std::string moduleDirectory = target->GetPropertyOrDefault(
+    "Swift_MODULE_DIRECTORY",
     target->LocalGenerator->GetCurrentBinaryDirectory());
-  std::string moduleFileName = GetTargetPropertyOrDefault(
-    target, "Swift_MODULE", moduleName + ".swiftmodule");
+  std::string moduleFileName = target->GetSwiftModuleFileName();
   return moduleDirectory + "/" + moduleFileName;
 }
 
@@ -1221,9 +1203,9 @@ void cmNinjaNormalTargetGenerator::WriteLinkStatement(
       return targetNames.Base;
     }();
 
-    vars["SWIFT_MODULE_NAME"] = GetSwiftModuleName(gt);
+    vars["SWIFT_MODULE_NAME"] = gt->GetSwiftModuleName();
     vars["SWIFT_MODULE"] = this->GetLocalGenerator()->ConvertToOutputFormat(
-      this->ConvertToNinjaPath(GetSwiftModulePath(gt)),
+      this->ConvertToNinjaPath(GetSwiftModulePathTree(gt)),
       cmOutputConverter::SHELL);
 
     vars["SWIFT_SOURCES"] = [this, config]() -> std::string {
@@ -1555,8 +1537,8 @@ void cmNinjaNormalTargetGenerator::WriteLinkStatement(
         // in order for there to be a swiftmodule to depend on
         if (dependency.Target &&
             dependency.Target->GetLinkerLanguage(config) == "Swift") {
-          std::string swiftmodule =
-            this->ConvertToNinjaPath(GetSwiftModulePath(dependency.Target));
+          std::string swiftmodule = this->ConvertToNinjaPath(
+            GetSwiftModulePathTree(dependency.Target));
           linkBuild.ImplicitDeps.emplace_back(swiftmodule);
         }
       }

Source/cmNinjaTargetGenerator.cxx

@@ -1947,15 +1947,6 @@ void cmNinjaTargetGenerator::WriteSwiftObjectBuildStatement(
     return;
   }
 
-  auto getTargetPropertyOrDefault =
-    [](cmGeneratorTarget const& target, std::string const& property,
-       std::string defaultValue) -> std::string {
-    if (cmValue value = target.GetProperty(property)) {
-      return *value;
-    }
-    return defaultValue;
-  };
-
   std::string const language = "Swift";
   std::string const objectDir = this->ConvertToNinjaPath(
     cmStrCat(this->GeneratorTarget->GetSupportDirectory(),
@@ -1971,12 +1962,12 @@ void cmNinjaTargetGenerator::WriteSwiftObjectBuildStatement(
   vars.emplace("restat", "1");
 
   std::string const moduleName =
-    getTargetPropertyOrDefault(target, "Swift_MODULE_NAME", target.GetName());
-  std::string const moduleDirectory = getTargetPropertyOrDefault(
-    target, "Swift_MODULE_DIRECTORY",
+    target.GetPropertyOrDefault("Swift_MODULE_NAME", target.GetName());
+  std::string const moduleDirectory = target.GetPropertyOrDefault(
+    "Swift_MODULE_DIRECTORY",
     target.LocalGenerator->GetCurrentBinaryDirectory());
-  std::string const moduleFilename = getTargetPropertyOrDefault(
-    target, "Swift_MODULE", cmStrCat(moduleName, ".swiftmodule"));
+  std::string const moduleFilename = target.GetPropertyOrDefault(
+    "Swift_MODULE", cmStrCat(moduleName, ".swiftmodule"));
   std::string const moduleFilepath =
     this->ConvertToNinjaPath(cmStrCat(moduleDirectory, '/', moduleFilename));
 
@@ -2097,12 +2088,12 @@ void cmNinjaTargetGenerator::WriteSwiftObjectBuildStatement(
     // swiftmodule to the ninja build graph.
     if (isImportableTarget(*dep)) {
       std::string const depModuleName =
-        getTargetPropertyOrDefault(*dep, "Swift_MODULE_NAME", dep->GetName());
-      std::string const depModuleDir = getTargetPropertyOrDefault(
-        *dep, "Swift_MODULE_DIRECTORY",
+        dep->GetPropertyOrDefault("Swift_MODULE_NAME", dep->GetName());
+      std::string const depModuleDir = dep->GetPropertyOrDefault(
+        "Swift_MODULE_DIRECTORY",
         dep->LocalGenerator->GetCurrentBinaryDirectory());
-      std::string const depModuleFilename = getTargetPropertyOrDefault(
-        *dep, "Swift_MODULE", cmStrCat(depModuleName, ".swiftmodule"));
+      std::string const depModuleFilename = dep->GetPropertyOrDefault(
+        "Swift_MODULE", cmStrCat(depModuleName, ".swiftmodule"));
       std::string const depModuleFilepath = this->ConvertToNinjaPath(
         cmStrCat(depModuleDir, '/', depModuleFilename));
       objBuild.ImplicitDeps.push_back(depModuleFilepath);