Front-end: add an option to ignore .swiftsourceinfo file for testing purposes

We generate .swiftsourceinfo for stdlib in the build directory because ABI checker
could issue diagnostics to the stdlib source. However, this may also change other
diagnostic tests. Both Brent and Jordan have raised concern about this. After
adding this flag, other diagnostic tests could ignore .swiftsourceinfo files even
though when they are present so our tests will reflect what most users experience
when sources for stdlib are unavailable.

Author: nkcsgexi

include/swift/Frontend/FrontendOptions.h

@@ -156,6 +156,9 @@ class FrontendOptions {
   /// Indicates that the input(s) should be parsed as the Swift stdlib.
   bool ParseStdlib = false;
 
+  /// Ignore .swiftsourceinfo file when trying to get source locations from module imported decls.
+  bool IgnoreSwiftSourceInfo = false;
+
   /// When true, emitted module files will always contain options for the
   /// debugger to use. When unset, the options will only be present if the
   /// module appears to not be a public module.

include/swift/Frontend/ModuleInterfaceLoader.h

@@ -134,8 +134,9 @@ class ModuleInterfaceLoader : public SerializedModuleLoaderBase {
       ASTContext &ctx, StringRef cacheDir, StringRef prebuiltCacheDir,
       DependencyTracker *tracker, ModuleLoadingMode loadMode,
       ArrayRef<std::string> PreferInterfaceForModules,
-      bool RemarkOnRebuildFromInterface)
-  : SerializedModuleLoaderBase(ctx, tracker, loadMode),
+      bool RemarkOnRebuildFromInterface, bool IgnoreSwiftSourceInfoFile)
+  : SerializedModuleLoaderBase(ctx, tracker, loadMode,
+                               IgnoreSwiftSourceInfoFile),
   CacheDir(cacheDir), PrebuiltCacheDir(prebuiltCacheDir),
   RemarkOnRebuildFromInterface(RemarkOnRebuildFromInterface),
   PreferInterfaceForModules(PreferInterfaceForModules)
@@ -161,12 +162,14 @@ class ModuleInterfaceLoader : public SerializedModuleLoaderBase {
   create(ASTContext &ctx, StringRef cacheDir, StringRef prebuiltCacheDir,
          DependencyTracker *tracker, ModuleLoadingMode loadMode,
          ArrayRef<std::string> PreferInterfaceForModules = {},
-         bool RemarkOnRebuildFromInterface = false) {
+         bool RemarkOnRebuildFromInterface = false,
+         bool IgnoreSwiftSourceInfoFile = false) {
     return std::unique_ptr<ModuleInterfaceLoader>(
       new ModuleInterfaceLoader(ctx, cacheDir, prebuiltCacheDir,
                                          tracker, loadMode,
                                          PreferInterfaceForModules,
-                                         RemarkOnRebuildFromInterface));
+                                         RemarkOnRebuildFromInterface,
+                                         IgnoreSwiftSourceInfoFile));
   }
 
   /// Append visible module names to \p names. Note that names are possibly

include/swift/Option/FrontendOptions.td

@@ -41,6 +41,9 @@ def emit_module_doc_path
 def emit_module_source_info : Flag<["-"], "emit-module-source-info">,
   HelpText<"Output module source info file">;
 
+def ignore_module_source_info : Flag<["-"], "ignore-module-source-info">,
+  HelpText<"Avoid getting source location from .swiftsourceinfo files">;
+
 def merge_modules
   : Flag<["-"], "merge-modules">, ModeOpt,
     HelpText<"Merge the input modules without otherwise processing them">;

include/swift/Serialization/SerializedModuleLoader.h

@@ -43,8 +43,10 @@ class SerializedModuleLoaderBase : public ModuleLoader {
 protected:
   ASTContext &Ctx;
   ModuleLoadingMode LoadMode;
+  bool IgnoreSwiftSourceInfoFile;
   SerializedModuleLoaderBase(ASTContext &ctx, DependencyTracker *tracker,
-                             ModuleLoadingMode LoadMode);
+                             ModuleLoadingMode LoadMode,
+                             bool IgnoreSwiftSourceInfoFile);
 
   void collectVisibleTopLevelModuleNamesImpl(SmallVectorImpl<Identifier> &names,
                                              StringRef extension) const;
@@ -168,8 +170,8 @@ class SerializedModuleLoaderBase : public ModuleLoader {
 class SerializedModuleLoader : public SerializedModuleLoaderBase {
 
   SerializedModuleLoader(ASTContext &ctx, DependencyTracker *tracker,
-                         ModuleLoadingMode loadMode)
-    : SerializedModuleLoaderBase(ctx, tracker, loadMode)
+                         ModuleLoadingMode loadMode, bool IgnoreSwiftSourceInfo)
+    : SerializedModuleLoaderBase(ctx, tracker, loadMode, IgnoreSwiftSourceInfo)
   {}
 
   std::error_code findModuleFilesInDirectory(
@@ -197,9 +199,10 @@ class SerializedModuleLoader : public SerializedModuleLoaderBase {
   /// into the given ASTContext.
   static std::unique_ptr<SerializedModuleLoader>
   create(ASTContext &ctx, DependencyTracker *tracker = nullptr,
-         ModuleLoadingMode loadMode = ModuleLoadingMode::PreferSerialized) {
+         ModuleLoadingMode loadMode = ModuleLoadingMode::PreferSerialized,
+         bool IgnoreSwiftSourceInfo = false) {
     return std::unique_ptr<SerializedModuleLoader>{
-      new SerializedModuleLoader(ctx, tracker, loadMode)
+      new SerializedModuleLoader(ctx, tracker, loadMode, IgnoreSwiftSourceInfo)
     };
   }
 };
@@ -211,8 +214,10 @@ class MemoryBufferSerializedModuleLoader : public SerializedModuleLoaderBase {
 
   MemoryBufferSerializedModuleLoader(ASTContext &ctx,
                                      DependencyTracker *tracker,
-                                     ModuleLoadingMode loadMode)
-      : SerializedModuleLoaderBase(ctx, tracker, loadMode) {}
+                                     ModuleLoadingMode loadMode,
+                                     bool IgnoreSwiftSourceInfo)
+      : SerializedModuleLoaderBase(ctx, tracker, loadMode,
+                                   IgnoreSwiftSourceInfo) {}
 
   std::error_code findModuleFilesInDirectory(
       AccessPathElem ModuleID, StringRef DirPath, StringRef ModuleFilename,
@@ -253,9 +258,11 @@ class MemoryBufferSerializedModuleLoader : public SerializedModuleLoaderBase {
   /// into the given ASTContext.
   static std::unique_ptr<MemoryBufferSerializedModuleLoader>
   create(ASTContext &ctx, DependencyTracker *tracker = nullptr,
-         ModuleLoadingMode loadMode = ModuleLoadingMode::PreferSerialized) {
+         ModuleLoadingMode loadMode = ModuleLoadingMode::PreferSerialized,
+         bool IgnoreSwiftSourceInfo = false) {
     return std::unique_ptr<MemoryBufferSerializedModuleLoader>{
-        new MemoryBufferSerializedModuleLoader(ctx, tracker, loadMode)};
+        new MemoryBufferSerializedModuleLoader(ctx, tracker, loadMode,
+                                               IgnoreSwiftSourceInfo)};
   }
 };
 

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -110,6 +110,7 @@ bool ArgsToFrontendOptionsConverter::convert(
 
   Opts.ParseStdlib |= Args.hasArg(OPT_parse_stdlib);
 
+  Opts.IgnoreSwiftSourceInfo |= Args.hasArg(OPT_ignore_module_source_info);
   computeHelpOptions();
 
   if (const Arg *A = Args.getLastArg(OPT_verify_generic_signatures)) {

lib/Frontend/Frontend.cpp

@@ -363,10 +363,11 @@ bool CompilerInstance::setUpModuleLoaders() {
       return true;
     }
   }
-
+  auto IgnoreSourceInfoFile =
+    Invocation.getFrontendOptions().IgnoreSwiftSourceInfo;
   if (Invocation.getLangOptions().EnableMemoryBufferImporter) {
     auto MemoryBufferLoader = MemoryBufferSerializedModuleLoader::create(
-        *Context, getDependencyTracker());
+        *Context, getDependencyTracker(), MLM, IgnoreSourceInfoFile);
     this->MemoryBufferLoader = MemoryBufferLoader.get();
     Context->addModuleLoader(std::move(MemoryBufferLoader));
   }
@@ -390,12 +391,13 @@ bool CompilerInstance::setUpModuleLoaders() {
     auto PIML = ModuleInterfaceLoader::create(
         *Context, ModuleCachePath, PrebuiltModuleCachePath,
         getDependencyTracker(), MLM, FEOpts.PreferInterfaceForModules,
-        FEOpts.RemarkOnRebuildFromModuleInterface);
+        FEOpts.RemarkOnRebuildFromModuleInterface, IgnoreSourceInfoFile);
     Context->addModuleLoader(std::move(PIML));
   }
 
   std::unique_ptr<SerializedModuleLoader> SML =
-    SerializedModuleLoader::create(*Context, getDependencyTracker(), MLM);
+    SerializedModuleLoader::create(*Context, getDependencyTracker(), MLM,
+                                   IgnoreSourceInfoFile);
   this->SML = SML.get();
   Context->addModuleLoader(std::move(SML));
 

lib/Serialization/SerializedModuleLoader.cpp

@@ -104,8 +104,10 @@ Optional<bool> forEachModuleSearchPath(
 
 // Defined out-of-line so that we can see ~ModuleFile.
 SerializedModuleLoaderBase::SerializedModuleLoaderBase(
-    ASTContext &ctx, DependencyTracker *tracker, ModuleLoadingMode loadMode)
-    : ModuleLoader(tracker), Ctx(ctx), LoadMode(loadMode) {}
+    ASTContext &ctx, DependencyTracker *tracker, ModuleLoadingMode loadMode,
+    bool IgnoreSwiftSourceInfoFile)
+    : ModuleLoader(tracker), Ctx(ctx), LoadMode(loadMode),
+      IgnoreSwiftSourceInfoFile(IgnoreSwiftSourceInfoFile) {}
 
 SerializedModuleLoaderBase::~SerializedModuleLoaderBase() = default;
 SerializedModuleLoader::~SerializedModuleLoader() = default;
@@ -326,11 +328,12 @@ std::error_code SerializedModuleLoaderBase::openModuleFiles(
       FS.getBufferForFile(ModulePath);
   if (!ModuleOrErr)
     return ModuleOrErr.getError();
-
-  // Open .swiftsourceinfo file if it's present.
-  openModuleSourceInfoFileIfPresent(ModuleID, ModulePath,
-                                    ModuleSourceInfoFileName,
-                                    ModuleSourceInfoBuffer);
+  if (!IgnoreSwiftSourceInfoFile) {
+    // Open .swiftsourceinfo file if it's present.
+    openModuleSourceInfoFileIfPresent(ModuleID, ModulePath,
+                                      ModuleSourceInfoFileName,
+                                      ModuleSourceInfoBuffer);
+  }
   auto ModuleDocErr =
     openModuleDocFile(ModuleID, ModuleDocPath, ModuleDocBuffer);
   if (ModuleDocErr)