[clang][lex] Always pass suggested module to `InclusionDirective()` callback (#81061)

This patch provides more information to the
`PPCallbacks::InclusionDirective()` hook. We now always pass the
suggested module, regardless of whether it was actually imported or not.
The extra `bool ModuleImported` parameter then denotes whether the
header `#include` will be automatically translated into import the the
module.

The main change is in `clang/lib/Lex/PPDirectives.cpp`, where we take
care to not modify `SuggestedModule` after it's been populated by
`LookupHeaderIncludeOrImport()`. We now exclusively use the `SM`
(`ModuleToImport`) variable instead, which has been equivalent to
`SuggestedModule` until now. This allows us to use the original
non-modified `SuggestedModule` for the callback itself.

(This patch turns out to be necessary for
https://github.com/apple/llvm-project/pull/8011).

1 files changed, 4 insertions, 3 deletions

diff --git a/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp b/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
index bdd72f8..4246c8c5 100644
--- a/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
+++ b/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
@@ -27,7 +27,8 @@ public:
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
                           OptionalFileEntryRef File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          StringRef RelativePath, const Module *SuggestedModule,
+                          bool ModuleImported,
                           SrcMgr::CharacteristicKind FileType) override;
   void EndOfMainFile() override;
 
@@ -81,8 +82,8 @@ static int getPriority(StringRef Filename, bool IsAngled, bool IsMainModule) {
 void IncludeOrderPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
     bool IsAngled, CharSourceRange FilenameRange, OptionalFileEntryRef File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
-    SrcMgr::CharacteristicKind FileType) {
+    StringRef SearchPath, StringRef RelativePath, const Module *SuggestedModule,
+    bool ModuleImported, SrcMgr::CharacteristicKind FileType) {
   // We recognize the first include as a special main module header and want
   // to leave it in the top position.
   IncludeDirective ID = {HashLoc, FilenameRange, std::string(FileName),