LLVM 19.0.0git
SEHFrameSupport.h
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1//===------- SEHFrameSupport.h - JITLink seh-frame utils --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// SEHFrame utils for JITLink.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_EXECUTIONENGINE_JITLINK_SEHFRAMESUPPORT_H
14#define LLVM_EXECUTIONENGINE_JITLINK_SEHFRAMESUPPORT_H
15
18#include "llvm/Support/Error.h"
20
21namespace llvm {
22namespace jitlink {
23/// This pass adds keep-alive edge from SEH frame sections
24/// to the parent function content block.
26public:
27 SEHFrameKeepAlivePass(StringRef SEHFrameSectionName)
28 : SEHFrameSectionName(SEHFrameSectionName) {}
29
31 auto *S = G.findSectionByName(SEHFrameSectionName);
32 if (!S)
33 return Error::success();
34
35 // Simply consider every block pointed by seh frame block as parants.
36 // This adds some unnecessary keep-alive edges to unwind info blocks,
37 // (xdata) but these blocks are usually dead by default, so they wouldn't
38 // count for the fate of seh frame block.
39 for (auto *B : S->blocks()) {
40 auto &DummySymbol = G.addAnonymousSymbol(*B, 0, 0, false, false);
41 DenseSet<Block *> Children;
42 for (auto &E : B->edges()) {
43 auto &Sym = E.getTarget();
44 if (!Sym.isDefined())
45 continue;
46 Children.insert(&Sym.getBlock());
47 }
48 for (auto *Child : Children)
49 Child->addEdge(Edge(Edge::KeepAlive, 0, DummySymbol, 0));
50 }
51 return Error::success();
52 }
53
54private:
55 StringRef SEHFrameSectionName;
56};
57
58} // end namespace jitlink
59} // end namespace llvm
60
61#endif // LLVM_EXECUTIONENGINE_JITLINK_SEHFRAMESUPPORT_H
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
Symbol * Sym
Definition: ELF_riscv.cpp:479
#define G(x, y, z)
Definition: MD5.cpp:56
Implements a dense probed hash-table based set.
Definition: DenseSet.h:271
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
static ErrorSuccess success()
Create a success value.
Definition: Error.h:334
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18