[cling] Backport jitlink ppc64 (root-project#13850)

* Backport JITLink ppc64 backend to LLVM-16

* Backport ELF part

* Backport PCREL relocations

* Use jitlink::Section::blocks::empty instead

* Backport TLS PCREL relocation

* [llvm-project] Synchronize with LLVM monorepo fork

---------

Co-authored-by: Jonas Hahnfeld <[email protected]>

interpreter/cling/lib/Interpreter/IncrementalJIT.cpp

@@ -356,7 +356,8 @@ static bool UseJITLink(const Triple& TT) {
   // LLJITBuilderState::prepareForConstruction.
   if (TT.getArch() == Triple::riscv64 ||
       (TT.isOSBinFormatMachO() &&
-       (TT.getArch() == Triple::aarch64 || TT.getArch() == Triple::x86_64))) {
+       (TT.getArch() == Triple::aarch64 || TT.getArch() == Triple::x86_64)) ||
+      (TT.isOSBinFormatELF() && TT.getArch() == Triple::ppc64le)) {
     jitLink = true;
   }
   // Finally, honor the user's choice by setting an environment variable.

interpreter/llvm-project/llvm-project.tag

@@ -1 +1 @@
-ROOT-llvm16-20240223-01
+ROOT-llvm16-20240321-01

interpreter/llvm-project/llvm/include/llvm/ExecutionEngine/JITLink/ELF_ppc64.h

@@ -0,0 +1,50 @@
+//===------ ELF_ppc64.h - JIT link functions for ELF/ppc64 ------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// jit-link functions for ELF/ppc64{le}.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_JITLINK_ELF_PPC64_H
+#define LLVM_EXECUTIONENGINE_JITLINK_ELF_PPC64_H
+
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+
+namespace llvm::jitlink {
+
+/// Create a LinkGraph from an ELF/ppc64 relocatable object.
+///
+/// Note: The graph does not take ownership of the underlying buffer, nor copy
+/// its contents. The caller is responsible for ensuring that the object buffer
+/// outlives the graph.
+///
+/// WARNING: The big-endian backend has not been tested yet.
+Expected<std::unique_ptr<LinkGraph>>
+createLinkGraphFromELFObject_ppc64(MemoryBufferRef ObjectBuffer);
+
+/// Create a LinkGraph from an ELF/ppc64le relocatable object.
+///
+/// Note: The graph does not take ownership of the underlying buffer, nor copy
+/// its contents. The caller is responsible for ensuring that the object buffer
+/// outlives the graph.
+Expected<std::unique_ptr<LinkGraph>>
+createLinkGraphFromELFObject_ppc64le(MemoryBufferRef ObjectBuffer);
+
+/// jit-link the given object buffer, which must be a ELF ppc64le object file.
+///
+/// WARNING: The big-endian backend has not been tested yet.
+void link_ELF_ppc64(std::unique_ptr<LinkGraph> G,
+                    std::unique_ptr<JITLinkContext> Ctx);
+
+/// jit-link the given object buffer, which must be a ELF ppc64le object file.
+void link_ELF_ppc64le(std::unique_ptr<LinkGraph> G,
+                      std::unique_ptr<JITLinkContext> Ctx);
+
+} // end namespace llvm::jitlink
+
+#endif // LLVM_EXECUTIONENGINE_JITLINK_ELF_PPC64_H

interpreter/llvm-project/llvm/include/llvm/ExecutionEngine/JITLink/TableManager.h

@@ -52,6 +52,21 @@ template <typename TableManagerImplT> class TableManager {
     return *EntryI->second;
   }
 
+  /// Register a pre-existing entry.
+  ///
+  /// Objects may include pre-existing table entries (e.g. for GOTs).
+  /// This method can be used to register those entries so that they will not
+  /// be duplicated by createEntry  the first time that getEntryForTarget is
+  /// called.
+  bool registerPreExistingEntry(Symbol &Target, Symbol &Entry) {
+    assert(Target.hasName() && "Edge cannot point to anonymous target");
+    auto Res = Entries.insert({
+        Target.getName(),
+        &Entry,
+    });
+    return Res.second;
+  }
+
 private:
   TableManagerImplT &impl() { return static_cast<TableManagerImplT &>(*this); }
   DenseMap<StringRef, Symbol *> Entries;