[libclang] Add function to get the buffer for a file

This can be used by clients in conjunction with an offset returned by
e.g. clang_getFileLocation. Now those clients do not need to also
open/read the file.

Differential Revision: https://reviews.llvm.org/D40643

llvm-svn: 319881

1 files changed, 21 insertions, 0 deletions

diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index b2edd42cb0d..49a1726ac5a 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -4162,6 +4162,27 @@ CXFile clang_getFile(CXTranslationUnit TU, const char *file_name) {
   return const_cast<FileEntry *>(FMgr.getFile(file_name));
 }
 
+const char *clang_getFileContents(CXTranslationUnit TU, CXFile file,
+                                  size_t *size) {
+  if (isNotUsableTU(TU)) {
+    LOG_BAD_TU(TU);
+    return nullptr;
+  }
+
+  const SourceManager &SM = cxtu::getASTUnit(TU)->getSourceManager();
+  FileID fid = SM.translateFile(static_cast<FileEntry *>(file));
+  bool Invalid = true;
+  llvm::MemoryBuffer *buf = SM.getBuffer(fid, &Invalid);
+  if (Invalid) {
+    if (size)
+      *size = 0;
+    return nullptr;
+  }
+  if (size)
+    *size = buf->getBufferSize();
+  return buf->getBufferStart();
+}
+
 unsigned clang_isFileMultipleIncludeGuarded(CXTranslationUnit TU,
                                             CXFile file) {
   if (isNotUsableTU(TU)) {