#include "llvm/ExecutionEngine/JITLink/COFF_x86_64.h"
#include "COFFLinkGraphBuilder.h"
-#include "EHFrameSupportImpl.h"
#include "JITLinkGeneric.h"
+#include "SEHFrameSupport.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/ExecutionEngine/JITLink/x86_64.h"
#include "llvm/Object/COFF.h"
const Triple &TT = G->getTargetTriple();
if (Ctx->shouldAddDefaultTargetPasses(TT)) {
// Add a mark-live pass.
- if (auto MarkLive = Ctx->getMarkLivePass(TT))
+ if (auto MarkLive = Ctx->getMarkLivePass(TT)) {
Config.PrePrunePasses.push_back(std::move(MarkLive));
- else
+ Config.PrePrunePasses.push_back(SEHFrameKeepAlivePass(".pdata"));
+ } else
Config.PrePrunePasses.push_back(markAllSymbolsLive);
// Add COFF edge lowering passes.
--- /dev/null
+//===------- SEHFrameSupport.h - JITLink seh-frame 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
+//
+//===----------------------------------------------------------------------===//
+//
+// SEHFrame utils for JITLink.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_JITLINK_SEHFRAMESUPPORT_H
+#define LLVM_EXECUTIONENGINE_JITLINK_SEHFRAMESUPPORT_H
+
+#include "llvm/ADT/Triple.h"
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+#include "llvm/ExecutionEngine/JITSymbol.h"
+#include "llvm/Support/Error.h"
+
+namespace llvm {
+namespace jitlink {
+/// This pass adds keep-alive edge from SEH frame sections
+/// to the parent function content block.
+class SEHFrameKeepAlivePass {
+public:
+ SEHFrameKeepAlivePass(StringRef SEHFrameSectionName)
+ : SEHFrameSectionName(SEHFrameSectionName) {}
+
+ Error operator()(LinkGraph &G) {
+ auto *S = G.findSectionByName(SEHFrameSectionName);
+ if (!S)
+ return Error::success();
+
+ // Simply consider every block pointed by seh frame block as parants.
+ // This adds some unnecessary keep-alive edges to unwind info blocks,
+ // (xdata) but these blocks are usually dead by default, so they wouldn't
+ // count for the fate of seh frame block.
+ for (auto *B : S->blocks()) {
+ auto &DummySymbol = G.addAnonymousSymbol(*B, 0, 0, false, false);
+ DenseSet<Block *> Children;
+ for (auto &E : B->edges()) {
+ auto &Sym = E.getTarget();
+ if (!Sym.isDefined())
+ continue;
+ Children.insert(&Sym.getBlock());
+ }
+ for (auto *Child : Children)
+ Child->addEdge(Edge(Edge::KeepAlive, 0, DummySymbol, 0));
+ }
+ return Error::success();
+ }
+
+private:
+ StringRef SEHFrameSectionName;
+};
+
+} // end namespace jitlink
+} // end namespace llvm
+
+#endif // LLVM_EXECUTIONENGINE_JITLINK_SEHFRAMESUPPORT_H
\ No newline at end of file
--- /dev/null
+# RUN: llvm-mc -filetype=obj -triple=x86_64-windows-msvc %s -o %t
+# RUN:
+# RUN: llvm-jitlink -abs __ImageBase=0xdeadbeaf -noexec %t \
+# RUN: -slab-allocate 100Kb -slab-address 0xfff00000 -slab-page-size 4096 \
+# RUN: -show-graph -noexec 2>&1 | FileCheck %s
+#
+# Check that basic seh frame inside pdata of alive function is not dead-stripped out.
+# CHECK: section .xdata:
+# CHECK-EMPTY:
+# CHECK-NEXT: block 0xfff00000 size = 0x00000008, align = 4, alignment-offset = 0
+# CHECK-NEXT: symbols:
+# CHECK-NEXT: 0xfff00000 (block + 0x00000000): size: 0x00000008, linkage: strong, scope: local, live - .xdata
+
+ .text
+
+ .def main;
+ .scl 2;
+ .type 32;
+ .endef
+ .globl main
+ .p2align 4, 0x90
+main:
+.seh_proc main
+ subq $40, %rsp
+ .seh_stackalloc 40
+ .seh_endprologue
+ movl $0, 36(%rsp)
+ nop
+ addq $40, %rsp
+ retq
+ .seh_endproc