[clang][deps] Migrate ModuleDepCollector to LexedFileChanged NFCI

[benlangmuir]

Summary

LexedFileChanged has the semantics we want of ignoring #line/etc. It's also consistent with other dep collectors like DependencyFileGenerator.

[jansvoboda11]

LGTM, but would be nice to have a test for this.

[benlangmuir]

Add a test

[benlangmuir]

In D143613#4115857, @jansvoboda11 wrote:

LGTM, but would be nice to have a test for this.

Oh, I didn't realize we didn't have one already. Added.

[jansvoboda11]

In D143613#4115935, @benlangmuir wrote:

In D143613#4115857, @jansvoboda11 wrote:

LGTM, but would be nice to have a test for this.

Oh, I didn't realize we didn't have one already. Added.

Thanks!

clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h

 /// Callback that records textual includes and direct modular includes/imports
 /// during preprocessing. At the end of the main file, it also collects
 /// transitive modular dependencies and passes everything to the
 /// \c DependencyConsumer of the parent \c ModuleDepCollector.
 class ModuleDepCollectorPP final : public PPCallbacks {
 public:
   ModuleDepCollectorPP(ModuleDepCollector &MDC) : MDC(MDC) {}
 
-  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
-                   SrcMgr::CharacteristicKind FileType,
-                   FileID PrevFID) override;
+  void LexedFileChanged(FileID FID, LexedFileChangeReason Reason,
+                        SrcMgr::CharacteristicKind FileType, FileID PrevFID,
+                        SourceLocation Loc) override;
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
                           OptionalFileEntryRef File, StringRef SearchPath,
                           StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void moduleImport(SourceLocation ImportLoc, ModuleIdPath Path,
                     const Module *Imported) override;

clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp

 void ModuleDepCollector::associateWithContextHash(const CompilerInvocation &CI,
                                                   ModuleDeps &Deps) {
   Deps.ID.ContextHash = getModuleContextHash(Deps, CI, EagerLoadModules);
   bool Inserted = ModuleDepsByID.insert({Deps.ID, &Deps}).second;
   (void)Inserted;
   assert(Inserted && "duplicate module mapping");
 }
 
-void ModuleDepCollectorPP::FileChanged(SourceLocation Loc,
-                                       FileChangeReason Reason,
+void ModuleDepCollectorPP::LexedFileChanged(FileID FID,
+                                            LexedFileChangeReason Reason,
                                             SrcMgr::CharacteristicKind FileType,
-                                       FileID PrevFID) {
-  if (Reason != PPCallbacks::EnterFile)
+                                            FileID PrevFID,
+                                            SourceLocation Loc) {
+  if (Reason != LexedFileChangeReason::EnterFile)
     return;
 
   // This has to be delayed as the context hash can change at the start of
   // `CompilerInstance::ExecuteAction`.
   if (MDC.ContextHash.empty()) {
     MDC.ContextHash = MDC.ScanInstance.getInvocation().getModuleHash();
     MDC.Consumer.handleContextHash(MDC.ContextHash);
   }
 
   SourceManager &SM = MDC.ScanInstance.getSourceManager();
 
   // Dependency generation really does want to go all the way to the
   // file entry for a source location to find out what is depended on.
   // We do not want #line markers to affect dependency generation!
-  if (std::optional<StringRef> Filename =
-          SM.getNonBuiltinFilenameForID(SM.getFileID(SM.getExpansionLoc(Loc))))
+  if (std::optional<StringRef> Filename = SM.getNonBuiltinFilenameForID(FID))
     MDC.addFileDep(llvm::sys::path::remove_leading_dotslash(*Filename));
 }
 
 void ModuleDepCollectorPP::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
     bool IsAngled, CharSourceRange FilenameRange, OptionalFileEntryRef File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {

clang/test/ClangScanDeps/line-directive.c

+// Check that we get the right file dependencies and not the declared paths from
+// line directives.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: sed "s|DIR|%/t|g" %t/cdb.json.template > %t/cdb.json
+
+// RUN: clang-scan-deps -compilation-database %t/cdb.json \
+// RUN:   -mode preprocess-dependency-directives -format experimental-full > %t/deps.json
+
+// RUN: cat %t/deps.json | sed 's:\\\\\?:/:g' | FileCheck %s -DPREFIX=%/t
+
+// CHECK:      "file-deps": [
+// CHECK-NEXT:   "[[PREFIX]]/tu.c"
+// CHECK-NEXT:   "[[PREFIX]]/header.h"
+// CHECK-NEXT: ]
+
+//--- cdb.json.template
+[{
+  "file": "DIR/tu.c",
+  "directory": "DIR",
+  "command": "clang -fsyntax-only DIR/tu.c"
+}]
+
+//--- other.h
+
+//--- other.c
+
+//--- header.h
+#line 100 "other.h"
+
+//--- tu.c
+#include "header.h"
+#line 100 "other.c"