[mac/lld] fill in current and compatibility version for LC_LOAD_(WEAK_)DYLIB

[thakis]

Summary

Not sure if anything actually depends on this, but it makes otool -L
output look nicer.

[int3]

lgtm

lld/test/MachO/implicit-dylibs.s

45 ↗

(On Diff #311995)

I think stub-link.s might be a better place to test this, since it contains a variety of generic TBD-related tests, whereas this file is more specifically for implicit dylib behavior.

[thakis]

Thanks! Moved the test.

lld/MachO/InputFiles.h

public:
   explicit DylibFile(MemoryBufferRef mb, DylibFile *umbrella = nullptr);
 
   explicit DylibFile(const llvm::MachO::InterfaceFile &interface,
                      DylibFile *umbrella = nullptr);
 
   static bool classof(const InputFile *f) { return f->kind() == DylibKind; }
 
   StringRef dylibName;
+  uint32_t compatibilityVersion = 0;
+  uint32_t currentVersion = 0;
   uint64_t ordinal = 0; // Ordinal numbering starts from 1, so 0 is a sentinel
   bool reexport = false;
   bool forceWeakImport = false;
 };
 
 // .a file
 class ArchiveFile : public InputFile {
 public:

lld/MachO/InputFiles.cpp

if (umbrella == nullptr)
     umbrella = this;
 
   auto *buf = reinterpret_cast<const uint8_t *>(mb.getBufferStart());
   auto *hdr = reinterpret_cast<const mach_header_64 *>(mb.getBufferStart());
 
   // Initialize dylibName.
   if (const load_command *cmd = findCommand(hdr, LC_ID_DYLIB)) {
     auto *c = reinterpret_cast<const dylib_command *>(cmd);
+    currentVersion = read32le(&c->dylib.current_version);
+    compatibilityVersion = read32le(&c->dylib.compatibility_version);
     dylibName = reinterpret_cast<const char *>(cmd) + read32le(&c->dylib.name);
   } else {
     error("dylib " + toString(this) + " missing LC_ID_DYLIB load command");
     return;
   }
 
   // Initialize symbols.
   DylibFile *exportingFile = isImplicitlyLinked(dylibName) ? this : umbrella;

 }
 
 DylibFile::DylibFile(const InterfaceFile &interface, DylibFile *umbrella)
     : InputFile(DylibKind, interface) {
   if (umbrella == nullptr)
     umbrella = this;
 
   dylibName = saver.save(interface.getInstallName());
+  compatibilityVersion = interface.getCompatibilityVersion().rawValue();
+  currentVersion = interface.getCurrentVersion().rawValue();
   DylibFile *exportingFile = isImplicitlyLinked(dylibName) ? this : umbrella;
   auto addSymbol = [&](const Twine &name) -> void {
     symbols.push_back(symtab->addDylib(saver.save(name), exportingFile,
                                        /*isWeakDef=*/false,
                                        /*isTlv=*/false));
   };
   // TODO(compnerd) filter out symbols based on the target platform
   // TODO: handle weak defs, thread locals

lld/MachO/Writer.cpp

void Writer::createLoadCommands() {
 
   uint64_t dylibOrdinal = 1;
   for (InputFile *file : inputFiles) {
     if (auto *dylibFile = dyn_cast<DylibFile>(file)) {
       // TODO: dylibs that are only referenced by weak refs should also be
       // loaded via LC_LOAD_WEAK_DYLIB.
       LoadCommandType lcType =
           dylibFile->forceWeakImport ? LC_LOAD_WEAK_DYLIB : LC_LOAD_DYLIB;
-      in.header->addLoadCommand(make<LCDylib>(lcType, dylibFile->dylibName));
+      in.header->addLoadCommand(make<LCDylib>(lcType, dylibFile->dylibName,
+                                              dylibFile->compatibilityVersion,
+                                              dylibFile->currentVersion));
       dylibFile->ordinal = dylibOrdinal++;
 
       if (dylibFile->reexport)
         in.header->addLoadCommand(
             make<LCDylib>(LC_REEXPORT_DYLIB, dylibFile->dylibName));
     }
   }
 

lld/test/MachO/dylink.s

 # REQUIRES: x86
 # RUN: mkdir -p %t
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %p/Inputs/libhello.s \
 # RUN:   -o %t/libhello.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %p/Inputs/libgoodbye.s \
 # RUN:   -o %t/libgoodbye.o
-# RUN: %lld -dylib -install_name \
-# RUN:   @executable_path/libhello.dylib %t/libhello.o -o %t/libhello.dylib
+# RUN: %lld -dylib -install_name @executable_path/libhello.dylib \
+# RUN:   -compatibility_version 10 -current_version 11 \
+# RUN:   %t/libhello.o -o %t/libhello.dylib
 # RUN: %lld -dylib -install_name \
 # RUN:   @executable_path/libgoodbye.dylib %t/libgoodbye.o -o %t/libgoodbye.dylib
 
 ## Make sure we are using the export trie and not the symbol table when linking
 ## against these dylibs.
 # RUN: llvm-strip %t/libhello.dylib
 # RUN: llvm-strip %t/libgoodbye.dylib
 # RUN: llvm-nm %t/libhello.dylib 2>&1 | FileCheck %s --check-prefix=NOSYM

 
 # RUN: llvm-objdump --macho --all-headers %t/dylink | FileCheck %s \
 # RUN:   --check-prefix=LOAD --implicit-check-not LC_LOAD_DYLIB
 ## Check that we don't create duplicate LC_LOAD_DYLIBs.
 # RUN: %lld -o %t/dylink -L%t -lhello -lhello -lgoodbye -lgoodbye %t/dylink.o
 # RUN: llvm-objdump --macho --all-headers %t/dylink | FileCheck %s \
 # RUN:   --check-prefix=LOAD --implicit-check-not LC_LOAD_DYLIB
 
-# LOAD:              cmd LC_LOAD_DYLIB
-# LOAD-NEXT:     cmdsize
-# LOAD-NEXT:        name @executable_path/libhello.dylib
-# LOAD:              cmd LC_LOAD_DYLIB
-# LOAD-NEXT:     cmdsize
-# LOAD-NEXT:        name @executable_path/libgoodbye.dylib
+# LOAD:                        cmd LC_LOAD_DYLIB
+# LOAD-NEXT:               cmdsize
+# LOAD-NEXT:                  name @executable_path/libhello.dylib
+# LOAD-NEXT:            time stamp
+# LOAD-NEXT:       current version 11.0.0
+# LOAD-NEXT: compatibility version 10.0.0
+# LOAD:                        cmd LC_LOAD_DYLIB
+# LOAD-NEXT:               cmdsize
+# LOAD-NEXT:                  name @executable_path/libgoodbye.dylib
 
 .section __TEXT,__text
 .globl _main
 
 _main:
   movl $0x2000004, %eax # write() syscall
   mov $1, %rdi # stdout
   movq _hello_world@GOTPCREL(%rip), %rsi

lld/test/MachO/stub-link.s

 # CHECK: Bind table:
 # CHECK-DAG: __DATA_CONST __got 0x[[ADDR]] pointer 0 libSystem ___nan
 # CHECK-DAG: __DATA __data {{.*}} pointer 0 CoreFoundation _OBJC_CLASS_$_NSObject
 # CHECK-DAG: __DATA __data {{.*}} pointer 0 CoreFoundation _OBJC_METACLASS_$_NSObject
 # CHECK-DAG: __DATA __data {{.*}} pointer 0 CoreFoundation _OBJC_IVAR_$_NSConstantArray._count
 # CHECK-DAG: __DATA __data {{.*}} pointer 0 CoreFoundation _OBJC_EHTYPE_$_NSException
 # CHECK-DAG: __DATA __data {{.*}} pointer 0 libc++abi      ___gxx_personality_v0
 
+# RUN: llvm-objdump --macho --all-headers %t/test | \
+# RUN:     FileCheck --check-prefix=LOAD %s
+
+# LOAD:          cmd LC_LOAD_DYLIB
+# LOAD-NEXT:               cmdsize
+# LOAD-NEXT:                  name /usr/lib/libSystem.B.dylib
+# LOAD-NEXT:            time stamp
+# LOAD-NEXT:       current version 1.1.0
+# LOAD-NEXT: compatibility version
+
 .section __TEXT,__text
 .global _main
 
 _main:
 ## This symbol is defined in an inner TAPI document within libSystem.tbd.
   movq ___nan@GOTPCREL(%rip), %rax
   ret