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Merge pull request #5846 from jckarter/refactor-section-registration
Runtime: Refactor platform-dependent image inspection code.
2 parents 81f9fa2 + 87b27c6 commit e9ce682

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9 files changed

+454
-368
lines changed

9 files changed

+454
-368
lines changed

‎stdlib/public/runtime/CMakeLists.txt

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@@ -40,6 +40,9 @@ set(swift_runtime_sources
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ErrorDefaultImpls.cpp
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Heap.cpp
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HeapObject.cpp
43+
ImageInspectionMachO.cpp
44+
ImageInspectionELF.cpp
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ImageInspectionWin32.cpp
4346
KnownMetadata.cpp
4447
Metadata.cpp
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MetadataLookup.cpp

‎stdlib/public/runtime/CygwinPort.cpp

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@@ -32,112 +32,6 @@ using namespace swift;
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static std::mutex swiftOnceMutex;
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35-
int swift::_swift_dl_iterate_phdr(int (*Callback)(struct dl_phdr_info *info,
36-
size_t size, void *data),
37-
void *data) {
38-
DWORD procId = GetCurrentProcessId();
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HANDLE procHandle =
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OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, procId);
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if (!procHandle) {
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swift::fatalError(/* flags = */ 0, "OpenProcess() failed");
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return 0;
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}
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int lastRet = 0;
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std::vector<HMODULE> modules(1024);
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DWORD neededSize;
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BOOL ret = EnumProcessModules(procHandle, modules.data(),
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modules.size() * sizeof(HMODULE), &neededSize);
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if (!ret) {
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swift::fatalError(/* flags = */ 0, "EnumProcessModules() failed");
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return 0;
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}
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if (modules.size() * sizeof(HMODULE) < neededSize) {
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modules.resize(neededSize / sizeof(HMODULE));
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ret = EnumProcessModules(procHandle, modules.data(),
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modules.size() * sizeof(HMODULE), &neededSize);
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}
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if (!ret) {
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swift::fatalError(/* flags = */ 0, "EnumProcessModules() failed");
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return 0;
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}
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for (unsigned i = 0; i < neededSize / sizeof(HMODULE); i++) {
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char modName[MAX_PATH];
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if (!GetModuleFileNameExA(procHandle, modules[i], modName,
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sizeof(modName))) {
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swift::fatalError(/* flags = */ 0, "GetModuleFileNameExA() failed");
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}
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dl_phdr_info hdr;
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hdr.dlpi_name = modName;
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hdr.dlpi_addr = modules[i];
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lastRet = Callback(&hdr, sizeof(hdr), data);
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if (lastRet != 0)
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break;
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}
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CloseHandle(procHandle);
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return lastRet;
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}
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uint8_t *swift::_swift_getSectionDataPE(void *handle, const char *sectionName,
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unsigned long *sectionSize) {
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// In Cygwin, dlopen() returns PE/COFF image pointer.
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// This is relying on undocumented feature of Windows API LoadLibrary().
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unsigned char *peStart = (unsigned char *)handle;
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const int kLocationOfNtHeaderOffset = 0x3C;
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int ntHeadersOffset =
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*reinterpret_cast<int32_t *>(peStart + kLocationOfNtHeaderOffset);
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bool assert1 =
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peStart[ntHeadersOffset] == 'P' && peStart[ntHeadersOffset + 1] == 'E';
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if (!assert1) {
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swift::fatalError(/* flags = */ 0, "_swift_getSectionDataPE()'s finding PE failed");
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}
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unsigned char *coff = peStart + ntHeadersOffset + 4;
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int16_t numberOfSections = *(int16_t *)(coff + 2);
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// SizeOfOptionalHeader
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int16_t sizeOfOptionalHeader = *(int16_t *)(coff + 16);
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const int kCoffFileHeaderSize = 20;
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unsigned char *sectionTableBase =
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coff + kCoffFileHeaderSize + sizeOfOptionalHeader;
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// Section Header Record
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const int kSectionRecordSize = 40;
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unsigned char *sectionHeader = sectionTableBase;
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for (int i = 0; i < numberOfSections; i++) {
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uint32_t virtualSize = *(uint32_t *)&sectionHeader[8];
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uint32_t virtualAddress = *(uint32_t *)&sectionHeader[12];
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char nameOfThisSection[9];
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memcpy(nameOfThisSection, sectionHeader, 8);
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nameOfThisSection[8] = '\0';
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if (strcmp(sectionName, nameOfThisSection) == 0) {
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*sectionSize = virtualSize;
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return (uint8_t *)handle + virtualAddress;
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}
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sectionHeader += kSectionRecordSize;
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}
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return nullptr;
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}
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14135
#if !defined(_MSC_VER)
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void swift::_swift_once_f(uintptr_t *predicate, void *context,
14337
void (*function)(void *)) {

‎stdlib/public/runtime/ImageInspection.h

Lines changed: 42 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,42 @@
1+
//===--- ImageInspection.h - Image inspection routines --------------------===//
2+
//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// This file includes routines that extract metadata from executable and
14+
// dynamic library image files generated by the Swift compiler. The
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// concrete implementations vary greatly by platform.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_RUNTIME_IMAGE_INSPECTION_H
20+
#define SWIFT_RUNTIME_IMAGE_INSPECTION_H
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#include <cstdint>
23+
24+
namespace swift {
25+
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/// Load the metadata from the image necessary to find a type's
27+
/// protocol conformance.
28+
void initializeProtocolConformanceLookup();
29+
30+
/// Load the metadata from the image necessary to find a type by name.
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void initializeTypeMetadataRecordLookup();
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// Callbacks to register metadata from an image to the runtime.
34+
35+
void addImageProtocolConformanceBlockCallback(const void *start,
36+
uintptr_t size);
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void addImageTypeMetadataRecordBlockCallback(const void *start,
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uintptr_t size);
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} // end namespace swift
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#endif // SWIFT_RUNTIME_IMAGE_INSPECTION_H

‎stdlib/public/runtime/ImageInspectionELF.cpp

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@@ -0,0 +1,101 @@
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//===--- ImageInspectionELFDynamic.cpp - ELF image inspection -------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// This file includes routines that interact with ld*.so on ELF-based platforms
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// to extract runtime metadata embedded in dynamically linked ELF images
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// generated by the Swift compiler.
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//
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//===----------------------------------------------------------------------===//
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#if defined(__ELF__) || defined(__ANDROID__)
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#include "ImageInspection.h"
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#include <elf.h>
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#include <link.h>
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#include <dlfcn.h>
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#include <string.h>
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27+
using namespace swift;
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29+
/// The symbol name in the image that identifies the beginning of the
30+
/// protocol conformances table.
31+
static const char ProtocolConformancesSymbol[] =
32+
".swift2_protocol_conformances_start";
33+
/// The symbol name in the image that identifies the beginning of the
34+
/// type metadata record table.
35+
static const char TypeMetadataRecordsSymbol[] =
36+
".swift2_type_metadata_start";
37+
38+
/// Context arguments passed down from dl_iterate_phdr to its callback.
39+
struct InspectArgs {
40+
/// Symbol name to look up.
41+
const char *symbolName;
42+
/// Callback function to invoke with the metadata block.
43+
void (*addBlock)(const void *start, uintptr_t size);
44+
};
45+
46+
static int iteratePHDRCallback(struct dl_phdr_info *info,
47+
size_t size, void *data) {
48+
const InspectArgs *inspectArgs = reinterpret_cast<const InspectArgs *>(data);
49+
void *handle;
50+
if (!info->dlpi_name || info->dlpi_name[0] == '\0') {
51+
handle = dlopen(nullptr, RTLD_LAZY);
52+
} else {
53+
handle = dlopen(info->dlpi_name, RTLD_LAZY | RTLD_NOLOAD);
54+
}
55+
56+
if (!handle) {
57+
// Not a shared library.
58+
return 0;
59+
}
60+
61+
const char *conformances =
62+
reinterpret_cast<const char*>(dlsym(handle, inspectArgs->symbolName));
63+
64+
if (!conformances) {
65+
// if there are no conformances, don't hold this handle open.
66+
dlclose(handle);
67+
return 0;
68+
}
69+
70+
// Extract the size of the conformances block from the head of the section.
71+
uint64_t conformancesSize;
72+
memcpy(&conformancesSize, conformances, sizeof(conformancesSize));
73+
conformances += sizeof(conformancesSize);
74+
75+
inspectArgs->addBlock(conformances, conformancesSize);
76+
77+
dlclose(handle);
78+
return 0;
79+
}
80+
81+
void swift::initializeProtocolConformanceLookup() {
82+
// Search the loaded dls. This only searches the already
83+
// loaded ones.
84+
// FIXME: Find a way to have this continue to happen for dlopen-ed images.
85+
// rdar://problem/19045112
86+
InspectArgs ProtocolConformanceArgs = {
87+
ProtocolConformancesSymbol,
88+
addImageProtocolConformanceBlockCallback
89+
};
90+
dl_iterate_phdr(iteratePHDRCallback, &ProtocolConformanceArgs);
91+
}
92+
93+
void swift::initializeTypeMetadataRecordLookup() {
94+
InspectArgs TypeMetadataRecordArgs = {
95+
TypeMetadataRecordsSymbol,
96+
addImageTypeMetadataRecordBlockCallback
97+
};
98+
dl_iterate_phdr(iteratePHDRCallback, &TypeMetadataRecordArgs);
99+
}
100+
101+
#endif // defined(__ELF__) || defined(__ANDROID__)

‎stdlib/public/runtime/ImageInspectionMachO.cpp

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@@ -0,0 +1,73 @@
1+
//===--- ImageInspectionMachO.cpp - Mach-O image inspection ---------------===//
2+
//
3+
// This source file is part of the Swift.org open source project
4+
//
5+
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
6+
// Licensed under Apache License v2.0 with Runtime Library Exception
7+
//
8+
// See http://swift.org/LICENSE.txt for license information
9+
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
10+
//
11+
//===----------------------------------------------------------------------===//
12+
//
13+
// This file includes routines that interact with dyld on Mach-O-based platforms
14+
// to extract runtime metadata embedded in images generated by the Swift
15+
// compiler.
16+
//
17+
//===----------------------------------------------------------------------===//
18+
19+
#if defined(__APPLE__) && defined(__MACH__)
20+
21+
#include "ImageInspection.h"
22+
#include <mach-o/dyld.h>
23+
#include <mach-o/getsect.h>
24+
#include <assert.h>
25+
26+
using namespace swift;
27+
28+
namespace {
29+
/// The Mach-O section name for the section containing protocol conformances.
30+
/// This lives within SEG_TEXT.
31+
constexpr const char ProtocolConformancesSection[] = "__swift2_proto";
32+
/// The Mach-O section name for the section containing type references.
33+
/// This lives within SEG_TEXT.
34+
constexpr const char TypeMetadataRecordSection[] = "__swift2_types";
35+
36+
template<const char *SECTION_NAME,
37+
void CONSUME_BLOCK(const void *start, uintptr_t size)>
38+
void addImageCallback(const mach_header *mh, intptr_t vmaddr_slide) {
39+
#ifdef __LP64__
40+
using mach_header_platform = mach_header_64;
41+
assert(mh->magic == MH_MAGIC_64 && "loaded non-64-bit image?!");
42+
#else
43+
using mach_header_platform = mach_header;
44+
#endif
45+
46+
// Look for a __swift2_proto section.
47+
unsigned long size;
48+
const uint8_t *section =
49+
getsectiondata(reinterpret_cast<const mach_header_platform *>(mh),
50+
SEG_TEXT, SECTION_NAME,
51+
&size);
52+
53+
if (!section)
54+
return;
55+
56+
CONSUME_BLOCK(section, size);
57+
}
58+
59+
} // end anonymous namespace
60+
61+
void swift::initializeProtocolConformanceLookup() {
62+
_dyld_register_func_for_add_image(
63+
addImageCallback<ProtocolConformancesSection,
64+
addImageProtocolConformanceBlockCallback>);
65+
}
66+
void swift::initializeTypeMetadataRecordLookup() {
67+
_dyld_register_func_for_add_image(
68+
addImageCallback<TypeMetadataRecordSection,
69+
addImageTypeMetadataRecordBlockCallback>);
70+
71+
}
72+
73+
#endif // defined(__APPLE__) && defined(__MACH__)

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