Merge pull request #76232 from cachemeifyoucan/eng/PR-135221984

[DependencyScanner] Drop macro search path if not needed

Author: cachemeifyoucan

include/swift/AST/ModuleDependencies.h

@@ -813,6 +813,9 @@ class ModuleDependencyInfo {
   void addMacroDependency(StringRef macroModuleName, StringRef libraryPath,
                           StringRef executablePath);
 
+  /// For a Source/Textual dependency, if it Has macro dependency.
+  bool hasMacroDependencies() const;
+
   /// Whether or not a queried module name is a `@Testable` import dependency
   /// of this module. Can only return `true` for Swift source modules.
   bool isTestableImport(StringRef moduleName) const;

lib/AST/ModuleDependencies.cpp

@@ -120,6 +120,18 @@ void ModuleDependencyInfo::addMacroDependency(StringRef macroModuleName,
     llvm_unreachable("Unexpected dependency kind");
 }
 
+bool ModuleDependencyInfo::hasMacroDependencies() const {
+  if (auto sourceModule =
+          dyn_cast<SwiftSourceModuleDependenciesStorage>(storage.get()))
+    return !sourceModule->textualModuleDetails.macroDependencies.empty();
+
+  if (auto interfaceModule =
+          dyn_cast<SwiftInterfaceModuleDependenciesStorage>(storage.get()))
+    return !interfaceModule->textualModuleDetails.macroDependencies.empty();
+
+  llvm_unreachable("Unexpected dependency kind");
+}
+
 bool ModuleDependencyInfo::isTestableImport(StringRef moduleName) const {
   if (auto swiftSourceDepStorage = getAsSwiftSourceModule())
     return swiftSourceDepStorage->testableImports.contains(moduleName);

lib/DependencyScan/ScanDependencies.cpp

@@ -159,6 +159,24 @@ parseBatchScanInputFile(ASTContext &ctx, StringRef batchInputPath,
   return result;
 }
 
+static void removeMacroSearchPaths(std::vector<std::string> &cmd) {
+  // Macro search path options.
+  static const llvm::StringSet<> macroSearchOptions = {
+      "-plugin-path",
+      "-external-plugin-path",
+      "-load-plugin-library",
+      "-load-plugin-executable",
+      "-in-process-plugin-server-path",
+  };
+
+  // Remove macro search path option and its argument.
+  for (auto it = cmd.begin(), ie=cmd.end(); it != ie; ++it) {
+    if (macroSearchOptions.contains(*it) && it + 1 != ie) {
+      it = cmd.erase(it, it + 2);
+    }
+  }
+}
+
 static llvm::Expected<llvm::cas::ObjectRef>
 updateModuleCacheKey(ModuleDependencyInfo &depInfo,
                      ModuleDependenciesCache &cache,
@@ -378,9 +396,15 @@ static llvm::Error resolveExplicitModuleInputs(
     // Update build command line.
     if (resolvingDepInfo.isSwiftInterfaceModule() ||
         resolvingDepInfo.isSwiftSourceModule()) {
-      // Update with casfs option.
       std::vector<std::string> newCommandLine =
           dependencyInfoCopy.getCommandline();
+
+      // If there are no external macro dependencies, drop all plugin search
+      // paths.
+      if (!resolvingDepInfo.hasMacroDependencies())
+        removeMacroSearchPaths(newCommandLine);
+
+      // Update with casfs option.
       for (auto rootID : rootIDs) {
         newCommandLine.push_back("-cas-fs");
         newCommandLine.push_back(rootID);
@@ -390,6 +414,7 @@ static llvm::Error resolveExplicitModuleInputs(
         newCommandLine.push_back("-clang-include-tree-root");
         newCommandLine.push_back(tree);
       }
+
       dependencyInfoCopy.updateCommandLine(newCommandLine);
     }
 

test/CAS/macro_deps.swift

@@ -29,6 +29,11 @@
 // RUN: %swift_frontend_plain @%t/SwiftShims.cmd
 // RUN: %S/Inputs/BuildCommandExtractor.py %t/deps.json Foo > %t/Foo.cmd
 // RUN: %swift_frontend_plain @%t/Foo.cmd
+// RUN: %S/Inputs/BuildCommandExtractor.py %t/deps.json Bar > %t/Bar.cmd
+// RUN: %swift_frontend_plain @%t/Bar.cmd
+
+// RUN: %FileCheck %s --check-prefix=PLUGIN_SEARCH --input-file=%t/Bar.cmd
+// PLUGIN_SEARCH-NOT: -external-plugin-path
 
 // RUN: %S/Inputs/BuildCommandExtractor.py %t/deps.json MyApp > %t/MyApp.cmd
 // RUN: %{python} %S/Inputs/GenerateExplicitModuleMap.py %t/deps.json > %t/map.json
@@ -87,6 +92,11 @@ public func assertFalse() {
     #assert(false)
 }
 
+//--- include/Bar.swiftinterface
+// swift-interface-format-version: 1.0
+// swift-module-flags: -enable-library-evolution -swift-version 5 -O -module-name Bar -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib
+public func bar()
+
 //--- test.swift
 import Foo
 @inlinable
@@ -96,6 +106,7 @@ public func test() {
 
 //--- main.swift
 import Test
+import Bar
 @freestanding(expression) macro stringify<T>(_ value: T) -> (T, String) = #externalMacro(module: "MacroTwo", type: "StringifyMacro")
 
 func appTest() {