[lld-macho] Initial groundwork for -bitcode_bundle
This diff creates an empty XAR file and copies it into
`__LLVM,__bundle`. Follow-up work will actually populate the contents of
that XAR.
Reviewed By: #lld-macho, gkm
Differential Revision: https://reviews.llvm.org/D100650
GitOrigin-RevId: ca6751043d8899b12baeb48621e61fb352cfee09
diff --git a/MachO/Config.h b/MachO/Config.h
index b07c711..d36a290 100644
--- a/MachO/Config.h
+++ b/MachO/Config.h
@@ -88,6 +88,7 @@
bool saveTemps = false;
bool adhocCodesign = false;
bool emitFunctionStarts = false;
+ bool emitBitcodeBundle = false;
bool timeTraceEnabled = false;
uint32_t headerPad;
uint32_t dylibCompatibilityVersion = 0;
diff --git a/MachO/Driver.cpp b/MachO/Driver.cpp
index 1eba029..6591f73 100644
--- a/MachO/Driver.cpp
+++ b/MachO/Driver.cpp
@@ -31,6 +31,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/BinaryFormat/Magic.h"
+#include "llvm/Config/config.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Object/Archive.h"
#include "llvm/Option/ArgList.h"
@@ -958,6 +959,12 @@
config->demangle = args.hasArg(OPT_demangle);
config->implicitDylibs = !args.hasArg(OPT_no_implicit_dylibs);
config->emitFunctionStarts = !args.hasArg(OPT_no_function_starts);
+ config->emitBitcodeBundle = args.hasArg(OPT_bitcode_bundle);
+
+#ifndef HAVE_LIBXAR
+ if (config->emitBitcodeBundle)
+ error("-bitcode_bundle unsupported because LLD wasn't built with libxar");
+#endif
if (const Arg *arg = args.getLastArg(OPT_install_name)) {
if (config->outputType != MH_DYLIB)
diff --git a/MachO/InputSection.h b/MachO/InputSection.h
index c6324ed..de76a01 100644
--- a/MachO/InputSection.h
+++ b/MachO/InputSection.h
@@ -101,6 +101,7 @@
constexpr const char stubHelper[] = "__stub_helper";
constexpr const char laSymbolPtr[] = "__la_symbol_ptr";
constexpr const char data[] = "__data";
+constexpr const char bitcodeBundle[] = "__bundle";
} // namespace section_names
diff --git a/MachO/Options.td b/MachO/Options.td
index 23a9034..822e74e 100644
--- a/MachO/Options.td
+++ b/MachO/Options.td
@@ -545,7 +545,6 @@
def bitcode_bundle : Flag<["-"], "bitcode_bundle">,
HelpText<"Generate an embedded bitcode bundle in the __LLVM,__bundle section of the output">,
- Flags<[HelpHidden]>,
Group<grp_bitcode>;
def bitcode_hide_symbols : Flag<["-"], "bitcode_hide_symbols">,
HelpText<"With -bitcode_bundle, hide all non-exported symbols from output bitcode bundle.">,
diff --git a/MachO/OutputSection.h b/MachO/OutputSection.h
index c526a83..f858f45 100644
--- a/MachO/OutputSection.h
+++ b/MachO/OutputSection.h
@@ -47,7 +47,6 @@
// Unneeded sections are omitted entirely (header and body).
virtual bool isNeeded() const { return true; }
- // Specifically finalizes addresses and section size, not content.
virtual void finalize() {
// TODO investigate refactoring synthetic section finalization logic into
// overrides of this function.
diff --git a/MachO/OutputSegment.h b/MachO/OutputSegment.h
index 7572123..559aae2 100644
--- a/MachO/OutputSegment.h
+++ b/MachO/OutputSegment.h
@@ -24,6 +24,7 @@
constexpr const char dataConst[] = "__DATA_CONST";
constexpr const char ld[] = "__LD"; // output only with -r
constexpr const char dwarf[] = "__DWARF";
+constexpr const char llvm[] = "__LLVM";
} // namespace segment_names
diff --git a/MachO/SyntheticSections.cpp b/MachO/SyntheticSections.cpp
index 60fd36d..5f48d58 100644
--- a/MachO/SyntheticSections.cpp
+++ b/MachO/SyntheticSections.cpp
@@ -20,6 +20,7 @@
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/Memory.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/Config/config.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/LEB128.h"
@@ -30,6 +31,11 @@
#include <sys/mman.h>
#endif
+#ifdef HAVE_LIBXAR
+#include <fcntl.h>
+#include <xar/xar.h>
+#endif
+
using namespace llvm;
using namespace llvm::MachO;
using namespace llvm::support;
@@ -1033,6 +1039,58 @@
memset(id + fileName.size(), 0, fileNamePad);
}
+BitcodeBundleSection::BitcodeBundleSection()
+ : SyntheticSection(segment_names::llvm, section_names::bitcodeBundle) {}
+
+class ErrorCodeWrapper {
+public:
+ ErrorCodeWrapper(std::error_code ec) : errorCode(ec.value()) {}
+ ErrorCodeWrapper(int ec) : errorCode(ec) {}
+ operator int() const { return errorCode; }
+
+private:
+ int errorCode;
+};
+
+#define CHECK_EC(exp) \
+ do { \
+ ErrorCodeWrapper ec(exp); \
+ if (ec) \
+ fatal(Twine("operation failed with error code ") + Twine(ec) + #exp); \
+ } while (0);
+
+void BitcodeBundleSection::finalize() {
+#ifdef HAVE_LIBXAR
+ using namespace llvm::sys::fs;
+ CHECK_EC(createTemporaryFile("bitcode-bundle", "xar", xarPath));
+
+ xar_t xar(xar_open(xarPath.data(), O_RDWR));
+ if (!xar)
+ fatal("failed to open XAR temporary file at " + xarPath);
+ CHECK_EC(xar_opt_set(xar, XAR_OPT_COMPRESSION, XAR_OPT_VAL_NONE));
+ // FIXME: add more data to XAR
+ CHECK_EC(xar_close(xar));
+
+ file_size(xarPath, xarSize);
+#endif // defined(HAVE_LIBXAR)
+}
+
+void BitcodeBundleSection::writeTo(uint8_t *buf) const {
+ using namespace llvm::sys::fs;
+ file_t handle =
+ CHECK(openNativeFile(xarPath, CD_OpenExisting, FA_Read, OF_None),
+ "failed to open XAR file");
+ std::error_code ec;
+ mapped_file_region xarMap(handle, mapped_file_region::mapmode::readonly,
+ xarSize, 0, ec);
+ if (ec)
+ fatal("failed to map XAR file");
+ memcpy(buf, xarMap.const_data(), xarSize);
+
+ closeFile(handle);
+ remove(xarPath);
+}
+
void macho::createSyntheticSymbols() {
auto addHeaderSymbol = [](const char *name) {
symtab->addSynthetic(name, in.header->isec, 0,
diff --git a/MachO/SyntheticSections.h b/MachO/SyntheticSections.h
index 38d966e..38fee86 100644
--- a/MachO/SyntheticSections.h
+++ b/MachO/SyntheticSections.h
@@ -488,6 +488,18 @@
void writeHashes(uint8_t *buf) const;
};
+class BitcodeBundleSection : public SyntheticSection {
+public:
+ BitcodeBundleSection();
+ uint64_t getSize() const override { return xarSize; }
+ void finalize() override;
+ void writeTo(uint8_t *buf) const override;
+
+private:
+ llvm::SmallString<261> xarPath;
+ uint64_t xarSize;
+};
+
static_assert((CodeSignatureSection::blobHeadersSize % 8) == 0, "");
static_assert((CodeSignatureSection::fixedHeadersSize % 8) == 0, "");
diff --git a/MachO/Writer.cpp b/MachO/Writer.cpp
index 9afe73d..52b69fa 100644
--- a/MachO/Writer.cpp
+++ b/MachO/Writer.cpp
@@ -803,6 +803,8 @@
codeSignatureSection = make<CodeSignatureSection>();
if (config->emitFunctionStarts)
functionStartsSection = make<FunctionStartsSection>();
+ if (config->emitBitcodeBundle)
+ make<BitcodeBundleSection>();
switch (config->outputType) {
case MH_EXECUTE:
diff --git a/test/MachO/bitcode-bundle.ll b/test/MachO/bitcode-bundle.ll
new file mode 100644
index 0000000..7daf96f
--- /dev/null
+++ b/test/MachO/bitcode-bundle.ll
@@ -0,0 +1,42 @@
+; REQUIRES: x86, xar
+; RUN: rm -rf %t; split-file %s %t
+; RUN: opt -module-summary %t/test.ll -o %t/test.o
+; RUN: opt -module-summary %t/foo.ll -o %t/foo.o
+; RUN: %lld -lSystem -bitcode_bundle %t/test.o %t/foo.o -o %t/test
+; RUN: llvm-objdump --macho --section=__LLVM,__bundle %t/test | FileCheck %s
+
+; CHECK: Contents of (__LLVM,__bundle) section
+; CHECK-NEXT: For (__LLVM,__bundle) section: xar header
+; CHECK-NEXT: magic XAR_HEADER_MAGIC
+; CHECK-NEXT: size 28
+; CHECK-NEXT: version 1
+; CHECK-NEXT: toc_length_compressed
+; CHECK-NEXT: toc_length_uncompressed
+; CHECK-NEXT: cksum_alg XAR_CKSUM_SHA1
+; CHECK-NEXT: For (__LLVM,__bundle) section: xar table of contents:
+; CHECK-NEXT: <?xml version="1.0" encoding="UTF-8"?>
+; CHECK-NEXT: <xar>
+; CHECK-NEXT: <toc>
+; CHECK-NEXT: <checksum style="sha1">
+; CHECK-NEXT: <size>20</size>
+; CHECK-NEXT: <offset>0</offset>
+; CHECK-NEXT: </checksum>
+; CHECK-NEXT: <creation-time>{{.*}}</creation-time>
+; CHECK-NEXT: </toc>
+; CHECK-NEXT: </xar>
+
+;--- foo.ll
+target triple = "x86_64-apple-darwin"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @foo() {
+ ret void
+}
+
+;--- test.ll
+target triple = "x86_64-apple-darwin"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @main() {
+ ret void
+}
diff --git a/test/MachO/invalid/no-libxar.ll b/test/MachO/invalid/no-libxar.ll
new file mode 100644
index 0000000..62a2599
--- /dev/null
+++ b/test/MachO/invalid/no-libxar.ll
@@ -0,0 +1,12 @@
+; REQUIRES: x86
+; UNSUPPORTED: xar
+; RUN: opt -module-summary %s -o %t.o
+; RUN: not %lld -lSystem -bitcode_bundle %t.o -o /dev/null 2>&1 | FileCheck %s
+; CHECK: error: -bitcode_bundle unsupported because LLD wasn't built with libxar
+
+target triple = "x86_64-apple-darwin"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @main() {
+ ret void
+}
diff --git a/test/lit.cfg.py b/test/lit.cfg.py
index 670f41f..2251042 100644
--- a/test/lit.cfg.py
+++ b/test/lit.cfg.py
@@ -90,6 +90,9 @@
config.have_libxml2):
config.available_features.add('manifest_tool')
+if config.have_libxar:
+ config.available_features.add('xar')
+
if config.have_libxml2:
config.available_features.add('libxml2')
diff --git a/test/lit.site.cfg.py.in b/test/lit.site.cfg.py.in
index 57fa15e..20d44da 100644
--- a/test/lit.site.cfg.py.in
+++ b/test/lit.site.cfg.py.in
@@ -15,6 +15,7 @@
config.target_triple = "@TARGET_TRIPLE@"
config.python_executable = "@Python3_EXECUTABLE@"
config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_libxar = @HAVE_LIBXAR@
config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
config.ld_lld_default_mingw = @LLD_DEFAULT_LD_LLD_IS_MINGW@
diff --git a/tools/lld/CMakeLists.txt b/tools/lld/CMakeLists.txt
index e77b216..827511d 100644
--- a/tools/lld/CMakeLists.txt
+++ b/tools/lld/CMakeLists.txt
@@ -20,6 +20,10 @@
lldWasm
)
+if(HAVE_LIBXAR)
+ target_link_libraries(lld PRIVATE ${XAR_LIB})
+endif()
+
install(TARGETS lld
RUNTIME DESTINATION bin)
