[libclang] Expose Rewriter in libclang API

[arphaman]

I think the methods that use the rewriter should be prefixed with clang_Rewriter_ to match the naming convention, e.g. clang_Rewriter_removeText, clang_Rewriter_dispose, clang_Rewriter_create.

Can you add a libclang unit test for the rewriter?

[jkorous]

• added tests
• renamed with prefix

[arphaman]

LGTM, with one comment below:

clang/include/clang-c/Rewrite.h

21

That should be prefixed with CX to be CXRewriter to match the naming convention.

clang/include/clang-c/Rewrite.h

+/*===-- clang-c/Rewrite.h - C Rewriter   --------------------------*- C -*-===*\
+|*                                                                            *|
+|* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
+|* Exceptions.                                                                *|
+|* See https://llvm.org/LICENSE.txt for license information.                  *|
+|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*/
+
+#ifndef LLVM_CLANG_C_REWRITE_H
+#define LLVM_CLANG_C_REWRITE_H
+
+#include "clang-c/CXString.h"
+#include "clang-c/ExternC.h"
+#include "clang-c/Index.h"
+#include "clang-c/Platform.h"
+
+LLVM_CLANG_C_EXTERN_C_BEGIN
+
+typedef void *Rewriter;
+
+/**
+ * Create Rewriter.
+ */
+CINDEX_LINKAGE Rewriter clang_createRewriter(CXTranslationUnit TU);
+
+/**
+ * Insert the specified string at the specified location in the original buffer.
+ */
+CINDEX_LINKAGE void clang_insertTextBefore(Rewriter Rew, CXSourceLocation Loc,
+                                           const char *Insert);
+
+/**
+ * Replace the specified range of characters in the input with the specified
+ * replacement.
+ */
+CINDEX_LINKAGE void clang_replaceText(Rewriter Rew, CXSourceRange ToBeReplaced,
+                                      const char *Replacement);
+
+/**
+ * Remove the specified range.
+ */
+CINDEX_LINKAGE void clang_removeText(Rewriter Rew, CXSourceRange ToBeRemoved);
+
+/**
+ * Save all changed files to disk.
+ * Returns 1 if any files were not saved successfully, returns 0 otherwise.
+ */
+CINDEX_LINKAGE int clang_overwriteChangedFiles(Rewriter Rew);
+
+/**
+ * Write out rewritten version of the main file to stdout.
+ */
+CINDEX_LINKAGE void clang_writeMainFileToStdOut(Rewriter Rew);
+
+/**
+ * Free the given Rewriter.
+ */
+CINDEX_LINKAGE void clang_disposeRewriter(Rewriter Rew);
+
+LLVM_CLANG_C_EXTERN_C_END
+
+#endif

clang/tools/libclang/CMakeLists.txt

set(SOURCES
   CXCompilationDatabase.cpp
   CXLoadedDiagnostic.cpp
   CXSourceLocation.cpp
   CXStoredDiagnostic.cpp
   CXString.cpp
   CXType.cpp
   Indexing.cpp
   FatalErrorHandler.cpp
+  Rewrite.cpp
 
   ADDITIONAL_HEADERS
   CIndexDiagnostic.h
   CIndexer.h
   CXCursor.h
   CXLoadedDiagnostic.h
   CXSourceLocation.h
   CXString.h

clang/tools/libclang/Rewrite.cpp

+//===- CXString.cpp - Routines for manipulating CXStrings -----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang-c/Rewrite.h"
+#include "CXSourceLocation.h"
+#include "CXTranslationUnit.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+
+struct CXTranslationUnitAndRewriter {
+  CXTranslationUnit TU;
+  clang::Rewriter Rewer;
+
+  CXTranslationUnitAndRewriter(CXTranslationUnit TU, clang::Rewriter &&Rewer)
+      : TU(TU), Rewer(std::move(Rewer)) {}
+};
+
+Rewriter clang_createRewriter(CXTranslationUnit TU) {
+  if (clang::cxtu::isNotUsableTU(TU)) {
+    LOG_BAD_TU(TU);
+    return {};
+  }
+  clang::ASTUnit *AU = clang::cxtu::getASTUnit(TU);
+  assert(AU);
+  return reinterpret_cast<Rewriter>(new CXTranslationUnitAndRewriter(
+      TU, clang::Rewriter(AU->getSourceManager(), AU->getLangOpts())));
+}
+
+void clang_insertTextBefore(Rewriter Rew, CXSourceLocation Loc,
+                            const char *Insert) {
+  assert(Rew);
+  clang::Rewriter &R =
+      reinterpret_cast<CXTranslationUnitAndRewriter *>(Rew)->Rewer;
+  R.InsertTextBefore(clang::cxloc::translateSourceLocation(Loc), Insert);
+}
+
+void clang_replaceText(Rewriter Rew, CXSourceRange ToBeReplaced,
+                       const char *Replacement) {
+  assert(Rew);
+  clang::Rewriter &R = *reinterpret_cast<clang::Rewriter *>(Rew);
+  CXTranslationUnit &TU =
+      reinterpret_cast<CXTranslationUnitAndRewriter *>(Rew)->TU;
+  R.ReplaceText(clang::cxloc::translateCharRangeToTokenRange(TU, ToBeReplaced),
+                Replacement);
+}
+
+void clang_removeText(Rewriter Rew, CXSourceRange ToBeRemoved) {
+  assert(Rew);
+  clang::Rewriter &R = *reinterpret_cast<clang::Rewriter *>(Rew);
+  CXTranslationUnit &TU =
+      reinterpret_cast<CXTranslationUnitAndRewriter *>(Rew)->TU;
+  R.RemoveText(clang::cxloc::translateCharRangeToTokenRange(TU, ToBeRemoved));
+}
+
+int clang_overwriteChangedFiles(Rewriter Rew) {
+  assert(Rew);
+  clang::Rewriter &R =
+      reinterpret_cast<CXTranslationUnitAndRewriter *>(Rew)->Rewer;
+  return R.overwriteChangedFiles();
+}
+
+void clang_writeMainFileToStdOut(Rewriter Rew) {
+  assert(Rew);
+  clang::Rewriter &R =
+      reinterpret_cast<CXTranslationUnitAndRewriter *>(Rew)->Rewer;
+  R.getEditBuffer(R.getSourceMgr().getMainFileID()).write(llvm::outs());
+}
+
+void clang_disposeRewriter(Rewriter Rew) {
+  if (Rew)
+    delete reinterpret_cast<clang::Rewriter *>(Rew);
+}
 No newline at end of file

clang/tools/libclang/libclang.exports

 clang_EvalResult_dispose
 clang_PrintingPolicy_getProperty
 clang_PrintingPolicy_setProperty
 clang_PrintingPolicy_dispose
 clang_install_aborting_llvm_fatal_error_handler
 clang_uninstall_llvm_fatal_error_handler
 clang_getVarDeclInitializer
 clang_hasVarDeclGlobalStorage
-clang_hasVarDeclExternalStorage
+clang_hasVarDeclExternalStorage
+clang_createRewriter
+clang_insertTextBefore
+clang_replaceText
+clang_removeText
+clang_overwriteChangedFiles
+clang_writeMainFileToStdOut
+clang_disposeRewriter
 No newline at end of file