Copybara import of the project:

--
878ab77 by Dave Lee <[email protected]>:

Stop declaring module swiftdeps output

--
ac3ceba by Dave Lee <[email protected]>:

Remove unused swift_dependencies_file()

RELNOTES: None.
PiperOrigin-RevId: 277068373

swift/internal/compiling.bzl

@@ -225,15 +225,6 @@ def declare_compile_outputs(
 
         output_map[src.path] = struct(**src_output_map)
 
-    # Output the module-wide `.swiftdeps` file, which is used for incremental
-    # builds.
-    swiftdeps = derived_files.swift_dependencies_file(
-        actions = actions,
-        target_name = target_name,
-    )
-    other_outputs.append(swiftdeps)
-    output_map[""] = {"swift-dependencies": swiftdeps.path}
-
     actions.write(
         content = struct(**output_map).to_json(),
         output = output_map_file,

swift/internal/derived_files.bzl

@@ -249,29 +249,6 @@ def _swiftmodule(actions, module_name):
     """
     return actions.declare_file("{}.swiftmodule".format(module_name))
 
-def _swift_dependencies_file(actions, target_name, src = None):
-    """Declares a file for compiler-generated Swift dependencies for a target.
-
-    This file is used during incremental compilation to determine which object
-    files and partial modules need to be rebuilt when a particular source file
-    changes.
-
-    Args:
-        actions: The context's actions object.
-        target_name: The name of the target being built.
-        src: An optional `File` representing the source file being compiled.
-
-    Returns:
-        The declared `File`.
-    """
-    if src:
-        dirname, basename = _intermediate_frontend_file_path(target_name, src)
-        return actions.declare_file(
-            paths.join(dirname, "{}.swiftdeps".format(basename)),
-        )
-
-    return actions.declare_file("{}.swiftdeps".format(target_name))
-
 def _whole_module_object_file(actions, target_name):
     """Declares a file for object files created with whole module optimization.
 
@@ -328,7 +305,6 @@ derived_files = struct(
     swiftdoc = _swiftdoc,
     swiftinterface = _swiftinterface,
     swiftmodule = _swiftmodule,
-    swift_dependencies_file = _swift_dependencies_file,
     whole_module_object_file = _whole_module_object_file,
     xctest_bundle = _xctest_bundle,
     xctest_runner_script = _xctest_runner_script,

tools/common/path_utils.cc

@@ -31,14 +31,31 @@ std::string Dirname(const std::string &path) {
 }
 
 std::string ReplaceExtension(const std::string &path,
-                             const std::string &new_extension) {
-  auto last_dot = path.rfind('.');
+                             const std::string &new_extension,
+                             bool all_extensions) {
   auto last_slash = path.rfind('/');
 
-  // If there was no dot, or if it was part of a previous path segment, append
-  // the extension to the path.
-  if (last_dot == std::string::npos || last_dot < last_slash) {
+  std::string::size_type dot;
+  if (all_extensions) {
+    // Find the first dot, signifying the first of all extensions.
+    if (last_slash != std::string::npos) {
+      dot = path.find('.', last_slash);
+    } else {
+      dot = path.find('.');
+    }
+  } else {
+    // Find the last extension only.
+    dot = path.rfind('.');
+    if (dot < last_slash) {
+      // If the dot was part of a previous path segment, treat it as if it
+      // wasn't found (it's not an extension of the filename).
+      dot = std::string::npos;
+    }
+  }
+
+  // If there was no dot append the extension to the path.
+  if (dot == std::string::npos) {
     return path + new_extension;
   }
-  return path.substr(0, last_dot) + new_extension;
+  return path.substr(0, dot) + new_extension;
 }

tools/common/path_utils.h

@@ -30,6 +30,7 @@ std::string Dirname(const std::string &path);
 // extension in the returned path. If the path does not have a file extension,
 // then new_extension is appended to it.
 std::string ReplaceExtension(const std::string &path,
-                             const std::string &new_extension);
+                             const std::string &new_extension,
+                             bool all_extensions = false);
 
 #endif  // BUILD_BAZEL_RULES_SWIFT_TOOLS_COMMON_PATH_UTILS_H_

tools/worker/output_file_map.cc

@@ -46,34 +46,31 @@ static std::string MakeIncrementalOutputPath(std::string path) {
 void OutputFileMap::ReadFromPath(const std::string &path) {
   std::ifstream stream(path);
   stream >> json_;
-  UpdateForIncremental();
+  UpdateForIncremental(path);
 }
 
 void OutputFileMap::WriteToPath(const std::string &path) {
   std::ofstream stream(path);
   stream << json_;
 }
 
-void OutputFileMap::UpdateForIncremental() {
+void OutputFileMap::UpdateForIncremental(const std::string &path) {
   nlohmann::json new_output_file_map;
   std::map<std::string, std::string> incremental_outputs;
 
+  // The empty string key is used to represent outputs that are for the whole
+  // module, rather than for a particular source file.
+  nlohmann::json module_map;
+  // Derive the swiftdeps file name from the .output-file-map.json name.
+  auto new_path = ReplaceExtension(path, ".swiftdeps", /*all_extensions=*/true);
+  auto swiftdeps_path = MakeIncrementalOutputPath(new_path);
+  module_map["swift-dependencies"] = swiftdeps_path;
+  new_output_file_map[""] = module_map;
+
   for (auto &element : json_.items()) {
     auto src = element.key();
     auto outputs = element.value();
 
-    // The empty string key is used to represent outputs that are for the whole
-    // module, rather than for a particular source file.
-    if (src.empty()) {
-      nlohmann::json empty_map = outputs;
-      auto path = outputs["swift-dependencies"].get<std::string>();
-      auto new_path = MakeIncrementalOutputPath(path);
-      empty_map["swift-dependencies"] = new_path;
-      incremental_outputs[path] = new_path;
-      new_output_file_map[""] = empty_map;
-      continue;
-    }
-
     nlohmann::json src_map;
 
     // Process the outputs for the current source file.

tools/worker/output_file_map.h

@@ -50,7 +50,7 @@ class OutputFileMap {
  private:
   // Modifies the output file map's JSON structure in-place to replace file
   // paths with equivalents in the incremental storage area.
-  void UpdateForIncremental();
+  void UpdateForIncremental(const std::string &path);
 
   nlohmann::json json_;
   std::map<std::string, std::string> incremental_outputs_;