llvm/unittests/ExecutionEngine/JITLink/EHFrameSupportTests.cpp

   1 //===----- EHFrameSupportTests.cpp - Unit tests for eh-frame support ------===//
   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 #include "llvm/ADT/STLExtras.h"
  10 #include "llvm/ExecutionEngine/JITLink/EHFrameSupport.h"
  11 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
  12 #include "llvm/ExecutionEngine/JITLink/MachO_arm64.h"
  13 #include "llvm/Testing/Support/Error.h"
  14 #include "gtest/gtest.h"
  15
  16 using namespace llvm;
  17 using namespace llvm::jitlink;
  18
  19 // TestObjectBytes contains a MachO arm64 object file with three symbols: foo,
  20 // bar, and main, with corresponding FDEs. It was generated with:
  21 //
  22 // % cat foo.cpp
  23 // extern "C" void e();
  24 // extern "C" void a() {
  25 //   try {
  26 //     e();
  27 //   } catch (int x) {
  28 //   }
  29 // }
  30 // extern "C" void b() noexcept {}
  31 // extern "C" void c() noexcept {}
  32 //
  33 // % clang++ --target=arm64-apple-darwin -femit-dwarf-unwind=always -c -o foo.o
  34 // \
  35 //   foo.c
  36 // % xxd -i foo.o
  37
  38 static const uint8_t TestObjectBytes[] = {
  39     0xcf, 0xfa, 0xed, 0xfe, 0x0c, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
  40     0x01, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x08, 0x02, 0x00, 0x00,
  41     0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x19, 0x00, 0x00, 0x00,
  42     0x88, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  43     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  44     0x00, 0x00, 0x00, 0x00, 0x90, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  45     0x28, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x01, 0x00, 0x00,
  46     0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00,
  47     0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x5f, 0x74, 0x65,
  48     0x78, 0x74, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  49     0x5f, 0x5f, 0x54, 0x45, 0x58, 0x54, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  50     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  51     0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x28, 0x02, 0x00, 0x00,
  52     0x02, 0x00, 0x00, 0x00, 0xb8, 0x03, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
  53     0x00, 0x04, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  54     0x00, 0x00, 0x00, 0x00, 0x5f, 0x5f, 0x67, 0x63, 0x63, 0x5f, 0x65, 0x78,
  55     0x63, 0x65, 0x70, 0x74, 0x5f, 0x74, 0x61, 0x62, 0x5f, 0x5f, 0x54, 0x45,
  56     0x58, 0x54, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  57     0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00,
  58     0x00, 0x00, 0x00, 0x00, 0x98, 0x02, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
  59     0xd8, 0x03, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  60     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  61     0x5f, 0x5f, 0x63, 0x6f, 0x6d, 0x70, 0x61, 0x63, 0x74, 0x5f, 0x75, 0x6e,
  62     0x77, 0x69, 0x6e, 0x64, 0x5f, 0x5f, 0x4c, 0x44, 0x00, 0x00, 0x00, 0x00,
  63     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x00, 0x00, 0x00,
  64     0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  65     0xb0, 0x02, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0xe0, 0x03, 0x00, 0x00,
  66     0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00,
  67     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x5f, 0x65, 0x68,
  68     0x5f, 0x66, 0x72, 0x61, 0x6d, 0x65, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  69     0x5f, 0x5f, 0x54, 0x45, 0x58, 0x54, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  70     0x00, 0x00, 0x00, 0x00, 0xe8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  71     0xa8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x03, 0x00, 0x00,
  72     0x03, 0x00, 0x00, 0x00, 0xf8, 0x03, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00,
  73     0x0b, 0x00, 0x00, 0x68, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  74     0x00, 0x00, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00,
  75     0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00,
  76     0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00,
  77     0x40, 0x04, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x20, 0x05, 0x00, 0x00,
  78     0x88, 0x00, 0x00, 0x00, 0x0b, 0x00, 0x00, 0x00, 0x50, 0x00, 0x00, 0x00,
  79     0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00,
  80     0x03, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00,
  81     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  82     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  83     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  84     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  85     0xff, 0x83, 0x00, 0xd1, 0xfd, 0x7b, 0x01, 0xa9, 0xfd, 0x43, 0x00, 0x91,
  86     0x00, 0x00, 0x00, 0x94, 0x01, 0x00, 0x00, 0x14, 0x10, 0x00, 0x00, 0x14,
  87     0xe8, 0x03, 0x01, 0xaa, 0xe0, 0x07, 0x00, 0xf9, 0xe8, 0x07, 0x00, 0xb9,
  88     0x01, 0x00, 0x00, 0x14, 0xe8, 0x07, 0x40, 0xb9, 0x08, 0x05, 0x00, 0x71,
  89     0xe8, 0x07, 0x9f, 0x1a, 0x68, 0x01, 0x00, 0x37, 0x01, 0x00, 0x00, 0x14,
  90     0xe0, 0x07, 0x40, 0xf9, 0x00, 0x00, 0x00, 0x94, 0x08, 0x00, 0x40, 0xb9,
  91     0xe8, 0x03, 0x00, 0xb9, 0x00, 0x00, 0x00, 0x94, 0x01, 0x00, 0x00, 0x14,
  92     0xfd, 0x7b, 0x41, 0xa9, 0xff, 0x83, 0x00, 0x91, 0xc0, 0x03, 0x5f, 0xd6,
  93     0xe0, 0x07, 0x40, 0xf9, 0x00, 0x00, 0x00, 0x94, 0xc0, 0x03, 0x5f, 0xd6,
  94     0xc0, 0x03, 0x5f, 0xd6, 0xff, 0x9b, 0x11, 0x01, 0x08, 0x0c, 0x04, 0x18,
  95     0x01, 0x10, 0x58, 0x00, 0x00, 0x01, 0x00, 0x00, 0xf0, 0xff, 0xff, 0xff,
  96     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  97     0x68, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00,
  98     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  99     0x68, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
 100     0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 101     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x6c, 0x00, 0x00, 0x00,
 102     0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
 103     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 104     0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 105     0x01, 0x7a, 0x52, 0x00, 0x01, 0x78, 0x1e, 0x01, 0x10, 0x0c, 0x1f, 0x00,
 106     0x18, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00, 0xe4, 0xff, 0xff, 0xff,
 107     0xff, 0xff, 0xff, 0xff, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 108     0x00, 0x00, 0x00, 0x00, 0x1c, 0x00, 0x00, 0x00, 0x34, 0x00, 0x00, 0x00,
 109     0xc8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x04, 0x00, 0x00, 0x00,
 110     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 111     0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x7a, 0x50, 0x4c,
 112     0x52, 0x00, 0x01, 0x78, 0x1e, 0x07, 0x9b, 0x9d, 0xff, 0xff, 0xff, 0x10,
 113     0x10, 0x0c, 0x1f, 0x00, 0x38, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00,
 114     0x8c, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x68, 0x00, 0x00, 0x00,
 115     0x00, 0x00, 0x00, 0x00, 0x08, 0x7b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 116     0xff, 0x44, 0x0e, 0x20, 0x48, 0x0c, 0x1d, 0x10, 0x9e, 0x01, 0x9d, 0x02,
 117     0x0a, 0x02, 0x48, 0x0c, 0x1f, 0x20, 0x48, 0x0e, 0x00, 0xde, 0xdd, 0x44,
 118     0x0b, 0x00, 0x00, 0x00, 0x64, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x2d,
 119     0x4c, 0x00, 0x00, 0x00, 0x0b, 0x00, 0x00, 0x2d, 0x40, 0x00, 0x00, 0x00,
 120     0x0a, 0x00, 0x00, 0x2d, 0x0c, 0x00, 0x00, 0x00, 0x0d, 0x00, 0x00, 0x2d,
 121     0x10, 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x7d, 0x40, 0x00, 0x00, 0x00,
 122     0x01, 0x00, 0x00, 0x06, 0x20, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x06,
 123     0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x06, 0x85, 0x00, 0x00, 0x00,
 124     0x04, 0x00, 0x00, 0x1e, 0x85, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x0e,
 125     0x74, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x1e, 0x74, 0x00, 0x00, 0x00,
 126     0x05, 0x00, 0x00, 0x0e, 0x63, 0x00, 0x00, 0x00, 0x0c, 0x00, 0x00, 0x7d,
 127     0x38, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x1e, 0x38, 0x00, 0x00, 0x00,
 128     0x07, 0x00, 0x00, 0x0e, 0x1c, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x1e,
 129     0x1c, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x0e, 0x70, 0x00, 0x00, 0x00,
 130     0x0e, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 131     0x54, 0x00, 0x00, 0x00, 0x0e, 0x02, 0x00, 0x00, 0x70, 0x00, 0x00, 0x00,
 132     0x00, 0x00, 0x00, 0x00, 0x76, 0x00, 0x00, 0x00, 0x0e, 0x02, 0x00, 0x00,
 133     0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4e, 0x00, 0x00, 0x00,
 134     0x0e, 0x03, 0x00, 0x00, 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 135     0x48, 0x00, 0x00, 0x00, 0x0e, 0x04, 0x00, 0x00, 0xe8, 0x00, 0x00, 0x00,
 136     0x00, 0x00, 0x00, 0x00, 0x45, 0x00, 0x00, 0x00, 0x0f, 0x01, 0x00, 0x00,
 137     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x42, 0x00, 0x00, 0x00,
 138     0x0f, 0x01, 0x00, 0x00, 0x68, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 139     0x3f, 0x00, 0x00, 0x00, 0x0f, 0x01, 0x00, 0x00, 0x6c, 0x00, 0x00, 0x00,
 140     0x00, 0x00, 0x00, 0x00, 0x2c, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
 141     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
 142     0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 143     0x08, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 144     0x00, 0x00, 0x00, 0x00, 0x1b, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
 145     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5a, 0x00, 0x00, 0x00,
 146     0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 147     0x3c, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 148     0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x5f, 0x5a, 0x54, 0x49, 0x69, 0x00,
 149     0x5f, 0x5f, 0x5f, 0x63, 0x78, 0x61, 0x5f, 0x62, 0x65, 0x67, 0x69, 0x6e,
 150     0x5f, 0x63, 0x61, 0x74, 0x63, 0x68, 0x00, 0x5f, 0x5f, 0x5f, 0x63, 0x78,
 151     0x61, 0x5f, 0x65, 0x6e, 0x64, 0x5f, 0x63, 0x61, 0x74, 0x63, 0x68, 0x00,
 152     0x5f, 0x5f, 0x55, 0x6e, 0x77, 0x69, 0x6e, 0x64, 0x5f, 0x52, 0x65, 0x73,
 153     0x75, 0x6d, 0x65, 0x00, 0x5f, 0x65, 0x00, 0x5f, 0x63, 0x00, 0x5f, 0x62,
 154     0x00, 0x5f, 0x61, 0x00, 0x6c, 0x74, 0x6d, 0x70, 0x33, 0x00, 0x6c, 0x74,
 155     0x6d, 0x70, 0x32, 0x00, 0x6c, 0x74, 0x6d, 0x70, 0x31, 0x00, 0x5f, 0x5f,
 156     0x5f, 0x67, 0x78, 0x78, 0x5f, 0x70, 0x65, 0x72, 0x73, 0x6f, 0x6e, 0x61,
 157     0x6c, 0x69, 0x74, 0x79, 0x5f, 0x76, 0x30, 0x00, 0x6c, 0x74, 0x6d, 0x70,
 158     0x30, 0x00, 0x47, 0x43, 0x43, 0x5f, 0x65, 0x78, 0x63, 0x65, 0x70, 0x74,
 159     0x5f, 0x74, 0x61, 0x62, 0x6c, 0x65, 0x30, 0x00};
 160
 161 llvm::MemoryBufferRef
 162     TestObject(StringRef(reinterpret_cast<const char *>(TestObjectBytes),
 163                          sizeof(TestObjectBytes)),
 164                "foo.o");
 165
 166 TEST(EHFrameCFIBlockInspector, BasicSuccessCase) {
 167   // Create a LinkGraph from the test object above and verify that
 168   // (1) There are two CIEs -- one with a personality function and one
 169   //     without.
 170   // (2) There are three FDEs -- two attached to the CIE with no
 171   //     personality, one attached to the CIE with a personality.
 172   // (3) Each FDE has an edge pointing to the CIE at the correct offset.
 173   // (4) Each function has exactly one FDE pointing at it.
 174
 175   auto G = cantFail(createLinkGraphFromMachOObject_arm64(
 176       TestObject, std::make_shared<orc::SymbolStringPool>()));
 177   cantFail(createEHFrameSplitterPass_MachO_arm64()(*G));
 178   cantFail(createEHFrameEdgeFixerPass_MachO_arm64()(*G));
 179
 180   auto *EHFrame = G->findSectionByName("__TEXT,__eh_frame");
 181   assert(EHFrame && "eh-frame missing?");
 182
 183   SmallVector<Block *, 2> CIEs;
 184   for (auto *B : EHFrame->blocks()) {
 185     auto CFIBI = EHFrameCFIBlockInspector::FromEdgeScan(*B);
 186     if (CFIBI.isCIE()) {
 187       CIEs.push_back(B);
 188       // If this CIE has an edge, check that getPersonalityEdge returns it.
 189       if (B->edges_size() != 0) {
 190         EXPECT_TRUE(!!CFIBI.getPersonalityEdge());
 191       }
 192     }
 193   }
 194   ASSERT_EQ(CIEs.size(), 2U);
 195
 196   // Make sure that the CIE with no edges is CIEs[0].
 197   if (CIEs[1]->edges_empty())
 198     std::swap(CIEs[0], CIEs[1]);
 199
 200   EXPECT_TRUE(CIEs[0]->edges_empty());
 201   EXPECT_EQ(CIEs[1]->edges_size(), 1U);
 202
 203   std::set<StringRef> Targets;
 204   for (auto *B : EHFrame->blocks()) {
 205     auto CFIBI = EHFrameCFIBlockInspector::FromEdgeScan(*B);
 206     if (CFIBI.isFDE()) {
 207       ASSERT_TRUE(!!CFIBI.getCIEEdge());
 208       ASSERT_TRUE(CFIBI.getCIEEdge()->getTarget().isDefined());
 209       auto &CIE = CFIBI.getCIEEdge()->getTarget().getBlock();
 210       ASSERT_TRUE(&CIE == CIEs[0] || &CIE == CIEs[1]);
 211
 212       ASSERT_TRUE(!!CFIBI.getPCBeginEdge());
 213       auto &PCBeginTarget = CFIBI.getPCBeginEdge()->getTarget();
 214       ASSERT_TRUE(PCBeginTarget.hasName());
 215       Targets.insert(*PCBeginTarget.getName());
 216
 217       // If the FDE points at CIEs[0] (the CIE without a personality) then it
 218       // should not have an LSDA. If it points to CIEs[1] then it should have
 219       // an LSDA.
 220       if (&CIE == CIEs[0])
 221         EXPECT_EQ(CFIBI.getLSDAEdge(), nullptr);
 222       else
 223         EXPECT_NE(CFIBI.getLSDAEdge(), nullptr);
 224     }
 225   }
 226
 227   EXPECT_EQ(Targets.size(), 3U) << "Unexpected number of FDEs";
 228   EXPECT_EQ(Targets.count("_a"), 1U);
 229   EXPECT_EQ(Targets.count("_b"), 1U);
 230   EXPECT_EQ(Targets.count("_c"), 1U);
 231 }
 232
 233 TEST(EHFrameCFIBlockInspector, ExternalPCBegin) {
 234   // Check that we don't crash if we transform the target of an FDE into an
 235   // external symbol before running edge-fixing.
 236   auto G = cantFail(createLinkGraphFromMachOObject_arm64(
 237       TestObject, std::make_shared<orc::SymbolStringPool>()));
 238
 239   // Make '_a' external.
 240   for (auto *Sym : G->defined_symbols())
 241     if (Sym->hasName() && *Sym->getName() == "_a") {
 242       G->makeExternal(*Sym);
 243       break;
 244     }
 245
 246   // Run the splitter and edge-fixer passes.
 247   cantFail(createEHFrameSplitterPass_MachO_arm64()(*G));
 248   cantFail(createEHFrameEdgeFixerPass_MachO_arm64()(*G));
 249 }