[CodeCompletion] Provide known module source file information

* 'CodeCompletionContext' now has 'requiresSourceFileInfo()' flag
* When 'true', 'SourceFiles' is populated.
* 'SourceFiles' is a list of pairs of a known module source
  file path and its up-to-date-ness
* Clients (i.e. 'CodeCompletionConsumer') can retrieve it from
  'CodeCompletionContext' in 'handleResults'
* Each completion item now has 'SourceFilePath' property
* C-APIs to get those informations

Author: rintaro

include/swift/IDE/CodeCompletion.h

@@ -633,6 +633,7 @@ class CodeCompletionResult {
 private:
   CodeCompletionString *CompletionString;
   StringRef ModuleName;
+  StringRef SourceFilePath;
   StringRef BriefDocComment;
   ArrayRef<StringRef> AssociatedUSRs;
   ArrayRef<std::pair<StringRef, StringRef>> DocWords;
@@ -740,7 +741,7 @@ class CodeCompletionResult {
                        CodeCompletionFlair Flair, unsigned NumBytesToErase,
                        CodeCompletionString *CompletionString,
                        CodeCompletionDeclKind DeclKind, bool IsSystem,
-                       StringRef ModuleName,
+                       StringRef ModuleName, StringRef SourceFilePath,
                        CodeCompletionResult::NotRecommendedReason NotRecReason,
                        StringRef BriefDocComment,
                        ArrayRef<StringRef> AssociatedUSRs,
@@ -749,10 +750,11 @@ class CodeCompletionResult {
                        CodeCompletionOperatorKind KnownOperatorKind)
       : Kind(ResultKind::Declaration),
         KnownOperatorKind(unsigned(KnownOperatorKind)),
-        SemanticContext(unsigned(SemanticContext)), Flair(unsigned(Flair.toRaw())),
-        NotRecommended(unsigned(NotRecReason)), IsSystem(IsSystem),
-        NumBytesToErase(NumBytesToErase), CompletionString(CompletionString),
-        ModuleName(ModuleName), BriefDocComment(BriefDocComment),
+        SemanticContext(unsigned(SemanticContext)),
+        Flair(unsigned(Flair.toRaw())), NotRecommended(unsigned(NotRecReason)),
+        IsSystem(IsSystem), NumBytesToErase(NumBytesToErase),
+        CompletionString(CompletionString), ModuleName(ModuleName),
+        SourceFilePath(SourceFilePath), BriefDocComment(BriefDocComment),
         AssociatedUSRs(AssociatedUSRs), DocWords(DocWords),
         TypeDistance(TypeDistance) {
     AssociatedKind = static_cast<unsigned>(DeclKind);
@@ -853,6 +855,16 @@ class CodeCompletionResult {
     return DocWords;
   }
 
+  void setSourceFilePath(StringRef value) {
+    SourceFilePath = value;
+  }
+
+  /// Returns the source file path where the associated decl was declared.
+  /// Returns an empty string if the information is not available.
+  StringRef getSourceFilePath() const {
+    return SourceFilePath;
+  }
+
   /// Print a debug representation of the code completion result to \p OS.
   void printPrefix(raw_ostream &OS) const;
   SWIFT_DEBUG_DUMP;
@@ -865,6 +877,15 @@ class CodeCompletionResult {
   static bool getDeclIsSystem(const Decl *D);
 };
 
+/// A pair of a file path and its up-to-date-ness.
+struct SourceFileAndUpToDate {
+  StringRef FilePath;
+  bool IsUpToDate;
+
+  SourceFileAndUpToDate(StringRef FilePath, bool IsUpToDate)
+      : FilePath(FilePath), IsUpToDate(IsUpToDate) {}
+};
+
 struct CodeCompletionResultSink {
   using AllocatorPtr = std::shared_ptr<llvm::BumpPtrAllocator>;
 
@@ -877,11 +898,13 @@ struct CodeCompletionResultSink {
 
   /// Whether to annotate the results with XML.
   bool annotateResult = false;
+  bool requiresSourceFileInfo = false;
 
   /// Whether to emit object literals if desired.
   bool includeObjectLiterals = true;
 
   std::vector<CodeCompletionResult *> Results;
+  std::vector<SourceFileAndUpToDate> SourceFiles;
 
   /// A single-element cache for module names stored in Allocator, keyed by a
   /// clang::Module * or swift::ModuleDecl *.
@@ -950,7 +973,10 @@ class CodeCompletionContext {
       : Cache(Cache) {}
 
   void setAnnotateResult(bool flag) { CurrentResults.annotateResult = flag; }
-  bool getAnnotateResult() { return CurrentResults.annotateResult; }
+  bool getAnnotateResult() const { return CurrentResults.annotateResult; }
+
+  void setRequiresSourceFileInfo(bool flag) { CurrentResults.requiresSourceFileInfo = flag; }
+  bool requiresSourceFileInfo() const { return CurrentResults.requiresSourceFileInfo; }
 
   void setIncludeObjectLiterals(bool flag) {
     CurrentResults.includeObjectLiterals = flag;
@@ -1006,6 +1032,7 @@ class PrintingCodeCompletionConsumer
   bool IncludeKeywords;
   bool IncludeComments;
   bool PrintAnnotatedDescription;
+  bool RequiresSourceFileInfo = false;
 
 public:
  PrintingCodeCompletionConsumer(llvm::raw_ostream &OS,
@@ -1017,8 +1044,8 @@ class PrintingCodeCompletionConsumer
        IncludeComments(IncludeComments),
        PrintAnnotatedDescription(PrintAnnotatedDescription) {}
 
- void handleResults(CodeCompletionContext &context) override;
- void handleResults(MutableArrayRef<CodeCompletionResult *> Results);
+  void handleResults(CodeCompletionContext &context) override;
+  void handleResults(MutableArrayRef<CodeCompletionResult *> Results);
 };
 
 /// Create a factory for code completion callbacks.

include/swift/IDE/ModuleSourceFileInfo.h

@@ -0,0 +1,39 @@
+//===--- ModuleSourceFileInfo.h ---------------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_IDE_MODULESOURCEFILEINFO_H
+#define SWIFT_IDE_MODULESOURCEFILEINFO_H
+
+#include "swift/AST/RawComment.h"
+#include "swift/Basic/BasicSourceInfo.h"
+#include "swift/Basic/LLVM.h"
+
+namespace swift {
+class ASTContext;
+class Decl;
+namespace ide {
+
+/// Get the source file path where \p D is declared. Returns an empty string
+/// if the information is not available.
+StringRef getSourceFilePathForDecl(const Decl *D);
+
+/// Check if the source file of \p info is up-to-date.
+///  * \c true if the mtime and the size are the same.
+///  * \c true if the interface has hasn't changed.
+///  * \c false otherwise.
+bool isSourceFileUpToDate(const BasicSourceFileInfo &info, ASTContext &Ctx);
+
+
+} // namespace ide
+} // namespace swift
+
+#endif // SWIFT_IDE_MODULESOURCEFILEINFO_H

lib/IDE/CMakeLists.txt

@@ -11,6 +11,7 @@ add_swift_host_library(swiftIDE STATIC
   FuzzyStringMatcher.cpp
   Refactoring.cpp
   ModuleInterfacePrinting.cpp
+  ModuleSourceFileInfo.cpp
   REPLCodeCompletion.cpp
   SwiftSourceDocInfo.cpp
   SyntaxModel.cpp

lib/IDE/CodeCompletion.cpp

@@ -33,6 +33,7 @@
 #include "swift/Frontend/FrontendOptions.h"
 #include "swift/IDE/CodeCompletionCache.h"
 #include "swift/IDE/CodeCompletionResultPrinter.h"
+#include "swift/IDE/ModuleSourceFileInfo.h"
 #include "swift/IDE/Utils.h"
 #include "swift/Parse/CodeCompletionCallbacks.h"
 #include "swift/Sema/IDETypeChecking.h"
@@ -1320,11 +1321,14 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
       }
     }
 
-    return new (*Sink.Allocator) CodeCompletionResult(
+    CodeCompletionResult *result = new (*Sink.Allocator) CodeCompletionResult(
         SemanticContext, Flair, NumBytesToErase, CCS, AssociatedDecl,
         ModuleName, NotRecReason, copyString(*Sink.Allocator, BriefComment),
         copyAssociatedUSRs(*Sink.Allocator, AssociatedDecl),
         copyArray(*Sink.Allocator, CommentWords), ExpectedTypeRelation);
+    if (!result->isSystem())
+      result->setSourceFilePath(getSourceFilePathForDecl(AssociatedDecl));
+    return result;
   }
 
   case CodeCompletionResult::ResultKind::Keyword:
@@ -6558,6 +6562,37 @@ static void postProcessResults(MutableArrayRef<CodeCompletionResult *> results,
   }
 }
 
+static void copyAllKnownSourceFileInfo(
+    ASTContext &Ctx, CodeCompletionResultSink &Sink) {
+  assert(Sink.SourceFiles.empty());
+
+  SmallVector<ModuleDecl *, 8> loadedModules;
+  loadedModules.reserve(Ctx.getNumLoadedModules());
+  for (auto &entry : Ctx.getLoadedModules())
+    loadedModules.push_back(entry.second);
+
+  auto &result = Sink.SourceFiles;
+  for (auto *M : loadedModules) {
+    // We don't need to check system modules.
+    if (M->isSystemModule())
+      continue;
+
+    M->collectBasicSourceFileInfo([&](const BasicSourceFileInfo &info) {
+      if (info.getFilePath().empty())
+        return;
+      
+      bool isUpToDate = false;
+      if (info.isFromSourceFile()) {
+        // 'SourceFile' is always "up-to-date" because we've just loaded.
+        isUpToDate = true;
+      } else {
+        isUpToDate = isSourceFileUpToDate(info, Ctx);
+      }
+      result.emplace_back(copyString(*Sink.Allocator, info.getFilePath()), isUpToDate);
+    });
+  }
+}
+
 static void deliverCompletionResults(CodeCompletionContext &CompletionContext,
                                      CompletionLookup &Lookup,
                                      DeclContext *DC,
@@ -6677,6 +6712,10 @@ static void deliverCompletionResults(CodeCompletionContext &CompletionContext,
                      CompletionContext.CodeCompletionKind, DC,
                      /*Sink=*/nullptr);
 
+  if (CompletionContext.requiresSourceFileInfo())
+    copyAllKnownSourceFileInfo(SF.getASTContext(),
+                               CompletionContext.getResultSink());
+
   Consumer.handleResultsAndModules(CompletionContext, RequestedModules, DC);
 }
 
@@ -7378,6 +7417,16 @@ void CodeCompletionCallbacksImpl::doneParsing() {
 
 void PrintingCodeCompletionConsumer::handleResults(
     CodeCompletionContext &context) {
+  if (context.requiresSourceFileInfo() &&
+      !context.getResultSink().SourceFiles.empty()) {
+    OS << "Known module source files\n";
+    for (auto &entry : context.getResultSink().SourceFiles) {
+      OS << (entry.IsUpToDate ? " + "  : " - ");
+      OS << entry.FilePath;
+      OS << "\n";
+    }
+    this->RequiresSourceFileInfo = true;
+  }
   auto results = context.takeResults();
   handleResults(results);
 }
@@ -7414,6 +7463,13 @@ void PrintingCodeCompletionConsumer::handleResults(
       OS << "; comment=" << comment;
     }
 
+    if (RequiresSourceFileInfo) {
+      StringRef sourceFilePath = Result->getSourceFilePath();
+      if (!sourceFilePath.empty()) {
+        OS << "; source=" << sourceFilePath;
+      }
+    }
+
     OS << "\n";
   }
   OS << "End completions\n";