[clang] Clang/Preprocessor: Not add headers of __has_include into DepColloctor (PR #120673)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: YunQiang Su (wzssyqa)

<details>
<summary>Changes</summary>

When we preprocess the bellow code with
    clang -E -MD -MF

  #if __has_include(<limits.h>)
    // DO NOTHING
  #endif
  #if 0 && __has_include(<limits.h>)
    #include <limits.h>
  #endif

It will list limits.h in the dependencies.

The same case with #__has_include_next

---
Full diff: https://github.com/llvm/llvm-project/pull/120673.diff


5 Files Affected:

- (modified) clang/include/clang/Lex/PPCallbacks.h (+4-2) 
- (modified) clang/lib/Frontend/DependencyFile.cpp (+7-5) 
- (modified) clang/lib/Lex/PPCallbacks.cpp (+7-4) 
- (modified) clang/lib/Lex/PPMacroExpansion.cpp (+2-1) 
- (added) clang/test/Preprocessor/dependencies-on-has-include.c (+23) 


``````````diff
diff --git a/clang/include/clang/Lex/PPCallbacks.h b/clang/include/clang/Lex/PPCallbacks.h
index 46cc564086f1c5..8e03c2b9a76dbb 100644
--- a/clang/include/clang/Lex/PPCallbacks.h
+++ b/clang/include/clang/Lex/PPCallbacks.h
@@ -370,7 +370,8 @@ class PPCallbacks {
   /// read.
   virtual void HasInclude(SourceLocation Loc, StringRef FileName, bool IsAngled,
                           OptionalFileEntryRef File,
-                          SrcMgr::CharacteristicKind FileType);
+                          SrcMgr::CharacteristicKind FileType,
+                          bool AddToDepCollector = true);
 
   /// Hook called when a source range is skipped.
   /// \param Range The SourceRange that was skipped. The range begins at the
@@ -621,7 +622,8 @@ class PPChainedCallbacks : public PPCallbacks {
 
   void HasInclude(SourceLocation Loc, StringRef FileName, bool IsAngled,
                   OptionalFileEntryRef File,
-                  SrcMgr::CharacteristicKind FileType) override;
+                  SrcMgr::CharacteristicKind FileType,
+                  bool AddToDepCollector = true) override;
 
   void PragmaOpenCLExtension(SourceLocation NameLoc, const IdentifierInfo *Name,
                              SourceLocation StateLoc, unsigned State) override {
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
index 528eae2c5283ea..931e29cd352211 100644
--- a/clang/lib/Frontend/DependencyFile.cpp
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -104,15 +104,17 @@ struct DepCollectorPPCallbacks : public PPCallbacks {
 
   void HasInclude(SourceLocation Loc, StringRef SpelledFilename, bool IsAngled,
                   OptionalFileEntryRef File,
-                  SrcMgr::CharacteristicKind FileType) override {
+                  SrcMgr::CharacteristicKind FileType,
+                  bool AddToDepCollector = true) override {
     if (!File)
       return;
     StringRef Filename =
         llvm::sys::path::remove_leading_dotslash(File->getName());
-    DepCollector.maybeAddDependency(Filename, /*FromModule=*/false,
-                                    /*IsSystem=*/isSystem(FileType),
-                                    /*IsModuleFile=*/false,
-                                    /*IsMissing=*/false);
+    if (AddToDepCollector)
+      DepCollector.maybeAddDependency(Filename, /*FromModule=*/false,
+                                      /*IsSystem=*/isSystem(FileType),
+                                      /*IsModuleFile=*/false,
+                                      /*IsMissing=*/false);
   }
 
   void EndOfMainFile() override {
diff --git a/clang/lib/Lex/PPCallbacks.cpp b/clang/lib/Lex/PPCallbacks.cpp
index cf473aa4df6564..79bb64892f6de6 100644
--- a/clang/lib/Lex/PPCallbacks.cpp
+++ b/clang/lib/Lex/PPCallbacks.cpp
@@ -15,14 +15,17 @@ PPCallbacks::~PPCallbacks() = default;
 
 void PPCallbacks::HasInclude(SourceLocation Loc, StringRef FileName,
                              bool IsAngled, OptionalFileEntryRef File,
-                             SrcMgr::CharacteristicKind FileType) {}
+                             SrcMgr::CharacteristicKind FileType,
+                             bool AddToDepCollector) {}
 
 // Out of line key method.
 PPChainedCallbacks::~PPChainedCallbacks() = default;
 
 void PPChainedCallbacks::HasInclude(SourceLocation Loc, StringRef FileName,
                                     bool IsAngled, OptionalFileEntryRef File,
-                                    SrcMgr::CharacteristicKind FileType) {
-  First->HasInclude(Loc, FileName, IsAngled, File, FileType);
-  Second->HasInclude(Loc, FileName, IsAngled, File, FileType);
+                                    SrcMgr::CharacteristicKind FileType,
+                                    bool AddToDepCollector) {
+  First->HasInclude(Loc, FileName, IsAngled, File, FileType, AddToDepCollector);
+  Second->HasInclude(Loc, FileName, IsAngled, File, FileType,
+                     AddToDepCollector);
 }
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index 347c13da0ad215..3429f08f45a2a5 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -1256,7 +1256,8 @@ static bool EvaluateHasIncludeCommon(Token &Tok, IdentifierInfo *II,
     SrcMgr::CharacteristicKind FileType = SrcMgr::C_User;
     if (File)
       FileType = PP.getHeaderSearchInfo().getFileDirFlavor(*File);
-    Callbacks->HasInclude(FilenameLoc, Filename, isAngled, File, FileType);
+    Callbacks->HasInclude(FilenameLoc, Filename, isAngled, File, FileType,
+                          false);
   }
 
   // Get the result value.  A result of true means the file exists.
diff --git a/clang/test/Preprocessor/dependencies-on-has-include.c b/clang/test/Preprocessor/dependencies-on-has-include.c
new file mode 100644
index 00000000000000..b6efbb22e18477
--- /dev/null
+++ b/clang/test/Preprocessor/dependencies-on-has-include.c
@@ -0,0 +1,23 @@
+// Test -MF and -E flags with has_include
+
+#ifdef TEST_HAS_INCLUDE_NEXT
+#if __has_include_next(<limits.h>)
+// DO NOTHING
+#endif
+#endif
+
+#ifdef TEST_HAS_INCLUDE
+#if __has_include(<limits.h>)
+// DO NOTHING
+#endif
+#endif
+
+// RUN: %clang -DTEST_HAS_INCLUDE -E -MD -MF - %s \
+// RUN:    | FileCheck -check-prefix=TEST-HAS %s
+// TEST-HAS: dependencies-on-has-include.o:
+// TEST-HAS-NOT: limits.h
+
+// RUN: %clang -Wno-include-next-outside-header -DTEST_HAS_INCLUDE_NEXT -E -MD -MF - %s \
+// RUN:    | FileCheck -check-prefix=TEST-HAS-N %s
+// TEST-HAS-N: dependencies-on-has-include.o:
+// TEST-HAS-N-NOT: limits.h

``````````

</details>


https://github.com/llvm/llvm-project/pull/120673