[Clang] Reintroduce obsolete libclang symbols to avoid an ABI break #149079
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@llvm/pr-subscribers-clang Author: None (Sirraide) ChangesFor more context, see #119269 (comment), but briefly, when removing ARCMigrate, I also removed some symbols in libclang, which constitutes an ABI break that we don’t want, so this pr reintroduces the removed symbols; the declarations are marked as deprecated for future removal, and the implementations print an error and do nothing, which is what we used to do when ARCMigrate was disabled. Full diff: https://github.com/llvm/llvm-project/pull/149079.diff 4 Files Affected:
diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h
index c35311c886413..b929585205aee 100644
--- a/clang/include/clang-c/Index.h
+++ b/clang/include/clang-c/Index.h
@@ -6953,6 +6953,21 @@ clang_getCursorUnaryOperatorKind(CXCursor cursor);
* @}
*/
+CINDEX_DEPRECATED
+typedef void *CXRemapping;
+
+CINDEX_DEPRECATED CINDEX_LINKAGE CXRemapping clang_getRemappings(const char *);
+
+CINDEX_DEPRECATED CINDEX_LINKAGE CXRemapping
+clang_getRemappingsFromFileList(const char **, unsigned);
+
+CINDEX_DEPRECATED CINDEX_LINKAGE unsigned clang_remap_getNumFiles(CXRemapping);
+
+CINDEX_DEPRECATED CINDEX_LINKAGE void
+clang_remap_getFilenames(CXRemapping, unsigned, CXString *, CXString *);
+
+CINDEX_DEPRECATED CINDEX_LINKAGE void clang_remap_dispose(CXRemapping);
+
LLVM_CLANG_C_EXTERN_C_END
#endif
diff --git a/clang/tools/libclang/CMakeLists.txt b/clang/tools/libclang/CMakeLists.txt
index b6662b66206b2..2b1e266f07392 100644
--- a/clang/tools/libclang/CMakeLists.txt
+++ b/clang/tools/libclang/CMakeLists.txt
@@ -42,6 +42,7 @@ set(SOURCES
Indexing.cpp
FatalErrorHandler.cpp
Rewrite.cpp
+ Obsolete.cpp
ADDITIONAL_HEADERS
CIndexDiagnostic.h
diff --git a/clang/tools/libclang/Obsolete.cpp b/clang/tools/libclang/Obsolete.cpp
new file mode 100644
index 0000000000000..3596f76e1be6f
--- /dev/null
+++ b/clang/tools/libclang/Obsolete.cpp
@@ -0,0 +1,48 @@
+//===- Obsolete.cpp - Obsolete libclang functions and types -------------===//
+//
+// 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
+//
+//===--------------------------------------------------------------------===//
+//
+// This file contains libclang symbols whose underlying functionality has been
+// removed from Clang, but which need to be kept around so as to retain ABI
+// compatibility.
+//
+//===--------------------------------------------------------------------===//
+
+#include "clang-c/CXString.h"
+#include "clang-c/Index.h"
+#include "clang-c/Platform.h"
+#include "llvm/Support/raw_ostream.h"
+
+extern "C" {
+
+// The functions below used to be part of the C API for ARCMigrate, which has
+// since been removed from Clang; they already used to print an error if Clang
+// was compiled without arcmt support, so we continue doing so.
+CXRemapping clang_getRemappings(const char *) {
+ llvm::errs() << "error: ARCMigrate has been removed from Clang";
+ return nullptr;
+}
+
+CXRemapping clang_getRemappingsFromFileList(const char **, unsigned) {
+ llvm::errs() << "error: ARCMigrate has been removed from Clang";
+ return nullptr;
+}
+
+unsigned clang_remap_getNumFiles(CXRemapping) {
+ llvm::errs() << "error: ARCMigrate has been removed from Clang";
+ return 0;
+}
+
+void clang_remap_getFilenames(CXRemapping, unsigned, CXString *, CXString *) {
+ llvm::errs() << "error: ARCMigrate has been removed from Clang";
+}
+
+void clang_remap_dispose(CXRemapping) {
+ llvm::errs() << "error: ARCMigrate has been removed from Clang";
+}
+
+} // extern "C"
diff --git a/llvm/utils/gn/secondary/clang/tools/libclang/BUILD.gn b/llvm/utils/gn/secondary/clang/tools/libclang/BUILD.gn
index 8f7beea152ab7..30b8bb61184bd 100644
--- a/llvm/utils/gn/secondary/clang/tools/libclang/BUILD.gn
+++ b/llvm/utils/gn/secondary/clang/tools/libclang/BUILD.gn
@@ -87,6 +87,7 @@ shared_library("libclang") {
"Index_Internal.h",
"Indexing.cpp",
"Rewrite.cpp",
+ "Obsolete.cpp",
]
if (host_os == "mac") {
ldflags = [
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Endilll
reviewed
Jul 16, 2025
AaronBallman
approved these changes
Jul 16, 2025
|
/cherry-pick 1600450 |
|
/pull-request #149100 |
|
Don't you have to undo the changes to clang/tools/libclang/libclang.map too? Else these might not be marked as exported on all platforms. (This: https://github.com/llvm/llvm-project/pull/119269/files#diff-2aa9e5e6908b0366b33796fa1f944b25d5b77abdf8eaceac7de55ccadaa7f04f) |
|
|
I’ve opened #149190 for this. |
nico
pushed a commit
that referenced
this pull request
Jul 16, 2025
This is a follow-up to #149079. Seems like we forgot about the fact that the symbols also need to be in `libclang.map`.
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/153/builds/38333 Here is the relevant piece of the build log for the reference |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/42/builds/5387 Here is the relevant piece of the build log for the reference |
tru
pushed a commit
to llvmbot/llvm-project
that referenced
this pull request
Jul 17, 2025
…lvm#149079) For more context, see llvm#119269 (comment), but briefly, when removing ARCMigrate, I also removed some symbols in libclang, which constitutes an ABI break that we don’t want, so this pr reintroduces the removed symbols; the declarations are marked as deprecated for future removal, and the implementations print an error and do nothing, which is what we used to do when ARCMigrate was disabled. (cherry picked from commit 1600450)
tru
pushed a commit
to llvmbot/llvm-project
that referenced
this pull request
Jul 17, 2025
This is a follow-up to llvm#149079. Seems like we forgot about the fact that the symbols also need to be in `libclang.map`. (cherry picked from commit 7e0fde0)
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For more context, see #119269 (comment), but briefly, when removing ARCMigrate, I also removed some symbols in libclang, which constitutes an ABI break that we don’t want, so this pr reintroduces the removed symbols; the declarations are marked as deprecated for future removal, and the implementations print an error and do nothing, which is what we used to do when ARCMigrate was disabled.