[readtapi] Setup simple stubify support

llvm/include/llvm/TextAPI/Utils.h

@@ -0,0 +1,34 @@
+//===- llvm/TextAPI/Utils.h - TAPI Utils -----------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Helper functionality used for Darwin specific operations.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TEXTAPI_UTILS_H
+#define LLVM_TEXTAPI_UTILS_H
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+
+#if !defined(PATH_MAX)
+#define PATH_MAX 1024
+#endif
+
+namespace llvm::MachO {
+
+using PathSeq = std::vector<std::string>;
+
+/// Replace extension considering frameworks.
+///
+/// \param Path Location of file.
+/// \param Extension File extension to update with.
+void replace_extension(SmallVectorImpl<char> &Path, const Twine &Extension);
+} // namespace llvm::MachO
+#endif // LLVM_TEXTAPI_UTILS_H

llvm/lib/TextAPI/CMakeLists.txt

@@ -13,6 +13,7 @@ add_llvm_component_library(LLVMTextAPI
   TextAPIError.cpp
   TextStub.cpp
   TextStubCommon.cpp
+  Utils.cpp
 
   ADDITIONAL_HEADER_DIRS
   "${LLVM_MAIN_INCLUDE_DIR}/llvm/TextAPI"

llvm/lib/TextAPI/Utils.cpp

@@ -0,0 +1,40 @@
+//===- Utils.cpp ----------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Implements utility functions for TextAPI Darwin operations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/TextAPI/Utils.h"
+
+using namespace llvm;
+using namespace llvm::MachO;
+
+void llvm::MachO::replace_extension(SmallVectorImpl<char> &Path,
+                                    const Twine &Extension) {
+  StringRef P(Path.begin(), Path.size());
+  auto ParentPath = sys::path::parent_path(P);
+  auto Filename = sys::path::filename(P);
+
+  if (!ParentPath.ends_with(Filename.str() + ".framework")) {
+    sys::path::replace_extension(Path, Extension);
+    return;
+  }
+  // Framework dylibs do not have a file extension, in those cases the new
+  // extension is appended. e.g. given Path: "Foo.framework/Foo" and Extension:
+  // "tbd", the result is "Foo.framework/Foo.tbd".
+  SmallString<8> Storage;
+  StringRef Ext = Extension.toStringRef(Storage);
+
+  // Append '.' if needed.
+  if (!Ext.empty() && Ext[0] != '.')
+    Path.push_back('.');
+
+  // Append extension.
+  Path.append(Ext.begin(), Ext.end());
+}