[Frontend] Teach LoadFromASTFile to take FileName by StringRef (NFC)

[kazutakahirata]

Without this patch, several callers of LoadFromASTFile construct an
instance of std::string to be passed as FileName, only to be converted
back to StringRef when LoadFromASTFile calls ReadAST.

This patch changes the type of FileName to StringRef and updates the
callers.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Kazu Hirata (kazutakahirata)

Changes

Without this patch, several callers of LoadFromASTFile construct an
instance of std::string to be passed as FileName, only to be converted
back to StringRef when LoadFromASTFile calls ReadAST.

This patch changes the type of FileName to StringRef and updates the
callers.

---

Full diff: https://github.com/llvm/llvm-project/pull/109583.diff

7 Files Affected:

• (modified) clang/include/clang/Frontend/ASTUnit.h (+2-2)
• (modified) clang/lib/CrossTU/CrossTranslationUnit.cpp (+3-3)
• (modified) clang/lib/Frontend/ASTUnit.cpp (+1-1)
• (modified) clang/lib/Frontend/FrontendAction.cpp (+5-5)
• (modified) clang/tools/c-index-test/core_main.cpp (+6-6)
• (modified) clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp (+1-1)
• (modified) clang/unittests/Frontend/ASTUnitTest.cpp (+2-2)

diff --git a/clang/include/clang/Frontend/ASTUnit.h b/clang/include/clang/Frontend/ASTUnit.h
index 080844893c13c9..8cefae8587aa34 100644
--- a/clang/include/clang/Frontend/ASTUnit.h
+++ b/clang/include/clang/Frontend/ASTUnit.h
@@ -692,8 +692,8 @@ class ASTUnit {
   ///
   /// \returns - The initialized ASTUnit or null if the AST failed to load.
   static std::unique_ptr<ASTUnit>
-  LoadFromASTFile(const std::string &Filename,
-                  const PCHContainerReader &PCHContainerRdr, WhatToLoad ToLoad,
+  LoadFromASTFile(StringRef Filename, const PCHContainerReader &PCHContainerRdr,
+                  WhatToLoad ToLoad,
                   IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
                   const FileSystemOptions &FileSystemOpts,
                   std::shared_ptr<HeaderSearchOptions> HSOpts,
diff --git a/clang/lib/CrossTU/CrossTranslationUnit.cpp b/clang/lib/CrossTU/CrossTranslationUnit.cpp
index 986470042bd83c..9faf2a8a173411 100644
--- a/clang/lib/CrossTU/CrossTranslationUnit.cpp
+++ b/clang/lib/CrossTU/CrossTranslationUnit.cpp
@@ -566,9 +566,9 @@ CrossTranslationUnitContext::ASTLoader::loadFromDump(StringRef ASTDumpPath) {
   IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
       new DiagnosticsEngine(DiagID, &*DiagOpts, DiagClient));
   return ASTUnit::LoadFromASTFile(
-      std::string(ASTDumpPath.str()),
-      CI.getPCHContainerOperations()->getRawReader(), ASTUnit::LoadEverything,
-      Diags, CI.getFileSystemOpts(), CI.getHeaderSearchOptsPtr());
+      ASTDumpPath, CI.getPCHContainerOperations()->getRawReader(),
+      ASTUnit::LoadEverything, Diags, CI.getFileSystemOpts(),
+      CI.getHeaderSearchOptsPtr());
 }
 
 /// Load the AST from a source-file, which is supposed to be located inside the
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 84e273a3949ef0..93836ec5402faa 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -802,7 +802,7 @@ void ASTUnit::ConfigureDiags(IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
 }
 
 std::unique_ptr<ASTUnit> ASTUnit::LoadFromASTFile(
-    const std::string &Filename, const PCHContainerReader &PCHContainerRdr,
+    StringRef Filename, const PCHContainerReader &PCHContainerRdr,
     WhatToLoad ToLoad, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
     const FileSystemOptions &FileSystemOpts,
     std::shared_ptr<HeaderSearchOptions> HSOpts,
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index a9c45e525c696c..81eea9c4c4dc58 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -625,8 +625,8 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
     StringRef InputFile = Input.getFile();
 
     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
-        std::string(InputFile), CI.getPCHContainerReader(),
-        ASTUnit::LoadPreprocessorOnly, ASTDiags, CI.getFileSystemOpts(),
+        InputFile, CI.getPCHContainerReader(), ASTUnit::LoadPreprocessorOnly,
+        ASTDiags, CI.getFileSystemOpts(),
         /*HeaderSearchOptions=*/nullptr);
     if (!AST)
       return false;
@@ -693,9 +693,9 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
     StringRef InputFile = Input.getFile();
 
     std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromASTFile(
-        std::string(InputFile), CI.getPCHContainerReader(),
-        ASTUnit::LoadEverything, Diags, CI.getFileSystemOpts(),
-        CI.getHeaderSearchOptsPtr(), CI.getLangOptsPtr());
+        InputFile, CI.getPCHContainerReader(), ASTUnit::LoadEverything, Diags,
+        CI.getFileSystemOpts(), CI.getHeaderSearchOptsPtr(),
+        CI.getLangOptsPtr());
 
     if (!AST)
       return false;
diff --git a/clang/tools/c-index-test/core_main.cpp b/clang/tools/c-index-test/core_main.cpp
index 003b1baef3a252..c43bff21962118 100644
--- a/clang/tools/c-index-test/core_main.cpp
+++ b/clang/tools/c-index-test/core_main.cpp
@@ -274,12 +274,12 @@ static bool printSourceSymbolsFromModule(StringRef modulePath,
 
   IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
       CompilerInstance::createDiagnostics(new DiagnosticOptions());
-  std::unique_ptr<ASTUnit> AU = ASTUnit::LoadFromASTFile(
-      std::string(modulePath), *pchRdr, ASTUnit::LoadASTOnly, Diags,
-      FileSystemOpts, HSOpts, /*LangOpts=*/nullptr,
-      /*OnlyLocalDecls=*/true, CaptureDiagsKind::None,
-      /*AllowASTWithCompilerErrors=*/true,
-      /*UserFilesAreVolatile=*/false);
+  std::unique_ptr<ASTUnit> AU =
+      ASTUnit::LoadFromASTFile(modulePath, *pchRdr, ASTUnit::LoadASTOnly, Diags,
+                               FileSystemOpts, HSOpts, /*LangOpts=*/nullptr,
+                               /*OnlyLocalDecls=*/true, CaptureDiagsKind::None,
+                               /*AllowASTWithCompilerErrors=*/true,
+                               /*UserFilesAreVolatile=*/false);
   if (!AU) {
     errs() << "failed to create TU for: " << modulePath << '\n';
     return true;
diff --git a/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp b/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
index c048f335f91ca1..3a2c32cfa4684b 100644
--- a/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
+++ b/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
@@ -155,7 +155,7 @@ static bool HandleAST(StringRef AstPath) {
   IntrusiveRefCntPtr<DiagnosticsEngine> DiagEngine = GetDiagnosticsEngine();
 
   std::unique_ptr<ASTUnit> Unit = ASTUnit::LoadFromASTFile(
-      AstPath.str(), CI->getPCHContainerOperations()->getRawReader(),
+      AstPath, CI->getPCHContainerOperations()->getRawReader(),
       ASTUnit::LoadASTOnly, DiagEngine, CI->getFileSystemOpts(),
       CI->getHeaderSearchOptsPtr());
 
diff --git a/clang/unittests/Frontend/ASTUnitTest.cpp b/clang/unittests/Frontend/ASTUnitTest.cpp
index 30d2731897e7f3..19b5d9bb41466a 100644
--- a/clang/unittests/Frontend/ASTUnitTest.cpp
+++ b/clang/unittests/Frontend/ASTUnitTest.cpp
@@ -92,8 +92,8 @@ TEST_F(ASTUnitTest, SaveLoadPreservesLangOptionsInPrintingPolicy) {
   auto HSOpts = std::make_shared<HeaderSearchOptions>();
 
   std::unique_ptr<ASTUnit> AU = ASTUnit::LoadFromASTFile(
-      std::string(ASTFileName.str()), PCHContainerOps->getRawReader(),
-      ASTUnit::LoadEverything, Diags, FileSystemOptions(), HSOpts);
+      ASTFileName, PCHContainerOps->getRawReader(), ASTUnit::LoadEverything,
+      Diags, FileSystemOptions(), HSOpts);
 
   if (!AU)
     FAIL() << "failed to load ASTUnit";