[IncludeTree] Support -frewrite-includes with include-tree

Add necessary PPCallbacks for include directives when the input file is
include tree so -frewrite-includes can generate the correct output.

rdar://125719747

Author: cachemeifyoucan

clang/lib/Lex/PPDirectives.cpp

@@ -1995,13 +1995,41 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     auto Include = CActions->handleIncludeDirective(
         *this, IncludePos, CurLexer->getSourceLocation());
 
+    auto InclusionCallback = [&](OptionalFileEntryRef FileRef,
+                                 const Module *SuggestedModule) {
+      if (!Callbacks || HashLoc.isInvalid())
+        return;
+
+      SmallString<128> FilenameBuffer;
+      StringRef Filename = getSpelling(FilenameTok, FilenameBuffer);
+      SourceLocation CharEnd = FilenameTok.getEndLoc();
+      CharSourceRange FilenameRange =
+          CharSourceRange::getCharRange(FilenameTok.getLocation(), CharEnd);
+      bool isAngled =
+          GetIncludeFilenameSpelling(FilenameTok.getLocation(), Filename);
+      SrcMgr::CharacteristicKind FileCharacter =
+          SourceMgr.getFileCharacteristic(FilenameTok.getLocation());
+      if (SuggestedModule)
+        Callbacks->InclusionDirective(HashLoc, IncludeTok, Filename, isAngled,
+                                      FilenameRange, OptionalFileEntryRef(),
+                                      /*SearchPath=*/"", /*RelativePath=*/"",
+                                      SuggestedModule,
+                                      /*ModuleImported=*/true, FileCharacter);
+      else
+        Callbacks->InclusionDirective(
+            HashLoc, IncludeTok, Filename, isAngled, FilenameRange, FileRef,
+            /*SearchPath=*/"", /*RelativePath=*/"", /*SuggestedModule=*/nullptr,
+            /*ModuleImported=*/false, FileCharacter);
+    };
+
     auto HandleIncludeFile = [&](const PPCachedActions::IncludeFile *File) {
       const FileEntry *FE = SourceMgr.getFileEntryForID(File->FID);
       bool IsImport =
           IncludeTok.getIdentifierInfo()->getPPKeywordID() == tok::pp_import;
       if (FE && IsImport) {
         HeaderInfo.getFileInfo(FE).isImport = true;
       }
+      InclusionCallback(SourceMgr.getFileEntryRefForID(File->FID), nullptr);
       EnterSourceFile(File->FID, nullptr, FilenameTok.getLocation(),
                       /*IsFirstIncludeOfFile*/ true);
 
@@ -2068,6 +2096,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
           return;
       }
 
+      InclusionCallback({}, Imported);
       makeModuleVisible(Imported, EndLoc);
       if (IncludeTok.getIdentifierInfo()->getPPKeywordID() !=
           tok::pp___include_macros)

clang/test/CAS/rewrite-includes.c

@@ -0,0 +1,84 @@
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+// RUN: sed -e "s|DIR|%/t|g" %t/cdb.json.template > %t/cdb.json
+// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-include-tree-full -cas-path %t/cas > %t/deps.json
+
+// RUN: %deps-to-rsp %t/deps.json --module-name dummy > %t/dummy.rsp
+// RUN: %deps-to-rsp %t/deps.json --module-name Mod > %t/mod.rsp
+// RUN: %deps-to-rsp %t/deps.json --module-name Spurious > %t/spurious.rsp
+// RUN: %deps-to-rsp %t/deps.json --tu-index 0 > %t/tu.rsp
+// RUN: %clang @%t/dummy.rsp
+// RUN: %clang @%t/mod.rsp
+// RUN: %clang @%t/spurious.rsp
+// RUN: %clang @%t/tu.rsp -frewrite-includes -w -E -o - | FileCheck %s
+
+// CHECK: int bar();{{$}}
+// CHECK-NEXT: #if 0 /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: #include "test.h"{{$}}
+// CHECK-NEXT: #endif /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: # 2 "{{.*[/\\]}}main.c"{{$}}
+// CHECK-NEXT: # 1 "{{.*[/\\]}}test.h" 1{{$}}
+// CHECK-NEXT: #if 0 /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: #include "dummy.h"{{$}}
+// CHECK-NEXT: #endif /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: # 1 "{{.*[/\\]}}test.h"{{$}}
+// CHECK-NEXT: #pragma clang module import dummy /* clang -frewrite-includes: implicit import */{{$}}
+// CHECK-NEXT: # 2 "{{.*[/\\]}}test.h"{{$}}
+// CHECK-NEXT: # 3 "{{.*[/\\]}}main.c" 2{{$}}
+// CHECK-NEXT: int foo();{{$}}
+// CHECK-NEXT: #if 0 /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: #include "dummy.h"{{$}}
+// CHECK-NEXT: #endif /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: # 4 "{{.*[/\\]}}main.c"{{$}}
+// CHECK-NEXT: #pragma clang module import dummy /* clang -frewrite-includes: implicit import */{{$}}
+// CHECK-NEXT: # 5 "{{.*[/\\]}}main.c"{{$}}
+// CHECK-NEXT: #if 0 /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: #include <Spurious/Missing.h>{{$}}
+// CHECK-NEXT: #endif /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: # 5 "{{.*[/\\]}}main.c"{{$}}
+// CHECK-NEXT: # 1 "{{.*[/\\]}}Missing.h" 1{{$}}
+// CHECK-NEXT: /* empty */
+// CHECK-NEXT: # 6 "{{.*[/\\]}}main.c" 2{{$}}
+// CHECK-NEXT: #if 0 /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: #include <Mod.h>{{$}}
+// CHECK-NEXT: #endif /* expanded by -frewrite-includes */{{$}}
+// CHECK-NEXT: # 6 "{{.*[/\\]}}main.c"{{$}}
+// CHECK-NEXT: #pragma clang module import Mod /* clang -frewrite-includes: implicit import */{{$}}
+// CHECK-NEXT: # 7 "{{.*[/\\]}}main.c"{{$}}
+
+//--- cdb.json.template
+[
+  {
+    "directory": "DIR",
+    "command": "clang -fsyntax-only -fmodules DIR/main.c -F DIR/frameworks -I DIR -fmodules-cache-path=DIR/module-cache",
+    "file": "DIR/t.c"
+  }
+]
+
+//--- dummy.h
+extern int dummy;
+
+//--- module.modulemap
+module dummy { header "dummy.h" }
+module Mod { header "Mod.h" }
+//--- frameworks/Spurious.framework/Modules/module.modulemap
+framework module Spurious {
+  umbrella header "Spurious.h"
+  module * { export * }
+}
+//--- frameworks/Spurious.framework/Headers/Spurious.h
+#include <Mod.h>
+//--- frameworks/Spurious.framework/Headers/Missing.h
+/* empty */
+//--- Mod.h
+typedef int mod_int;
+//--- test.h
+#include "dummy.h"
+//--- main.c
+int bar();
+#include "test.h"
+int foo();
+#include "dummy.h"
+#include <Spurious/Missing.h>
+#include <Mod.h>