[mach-o] wire up a dylib's install-name in more places

[t.p.northover]

Summary

Hi,

This adds support for installName to the various transformations an object file may go through. I *think* LC_ID_DYLIB commands will be interepreted and written correctly after this.

I know we were trying to keep tests contained in a single file and avoid using "Inputs/", but I can't think of a way to combine the two yaml files into a single one and get lld to act on them correctly.

Does it look OK?

Cheers.

Tim.

[kledzik]

One other thing to fix: If a dylib is built and there is no -install_name on the command line, whatever path is passed to -o should be used as the install name.

Also what case of multiple yaml docs in one test case file is not working (and leading you to use Inputs/ files)/

lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp

349–353

LC_ID_DYLIB traditionally goes after the LC_SEGMENT commands. So, just move this code up in the function.

713–729

Same here. Move this up so LC_ID_DYLIB lands after LC_SEGMENT commands.

FYI, the timestamp should always be 1. The two _versions come from command line arguments.

[t.p.northover]

Hi Nick,

lib/ReaderWriter/MachO/MachONormalizedFileBinaryReader.cpp

         }
       }
     }
+    if (cmd == LC_ID_DYLIB) {
+      const dylib_command *dl = reinterpret_cast<const dylib_command*>(lc);
+      dylib_command tempDL;
+      if (swap) {
+        tempDL = *dl; swapStruct(tempDL); dl = &tempDL;
+      }
+
+      f->installName = lc + dl->dylib.name;
+    }
     return false;
   });
   if (ec)

lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp

     ++count;
   }
 
+  // If creating a dylib, add LC_ID_DYLIB.
+  if (_file.fileType == llvm::MachO::MH_DYLIB) {
+    size += sizeof(dylib_command) + pointerAlign(_file.installName.size() + 1);
+    ++count;
+  }
+
   // Add LC_LOAD_DYLIB for each dependent dylib.
   for (const DependentDylib &dep : _file.dependentDylibs) {
     size += sizeof(dylib_command) + pointerAlign(dep.path.size()+1);

       lc += sizeof(entry_point_command);
     }
 
+    // Add LC_ID_DYLIB command for dynamic libraries.
+    if (_file.fileType == llvm::MachO::MH_DYLIB) {
+      dylib_command *dc = reinterpret_cast<dylib_command*>(lc);
+      StringRef path = _file.installName;
+      uint32_t size = sizeof(dylib_command) + pointerAlign(path.size() + 1);
+      dc->cmd                         = LC_ID_DYLIB;
+      dc->cmdsize                     = size;
+      dc->dylib.name                  = sizeof(dylib_command); // offset
+      dc->dylib.timestamp             = 0; // FIXME
+      dc->dylib.current_version       = 0; // FIXME
+      dc->dylib.compatibility_version = 0; // FIXME
+      if (_swap)
+        swapStruct(*dc);
+      memcpy(lc + sizeof(dylib_command), path.begin(), path.size());
+      lc[sizeof(dylib_command) + path.size()] = '\0';
+      lc += size;
+    }
+
     // Add LC_LOAD_DYLIB commands
     for (const DependentDylib &dep : _file.dependentDylibs) {
       dylib_command* dc = reinterpret_cast<dylib_command*>(lc);

       lc[sizeof(dylib_command)+dep.path.size()] = '\0';
       lc += size;
     }
-
   }
   return ec;
 }

lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp

   f->arch = context.arch();
   f->fileType = context.outputMachOType();
   f->flags = util.fileFlags();
+  f->installName = context.installName();
   util.copySegmentInfo(normFile);
   util.copySections(normFile);
   util.addDependentDylibs(atomFile, normFile);

lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp

 ErrorOr<std::unique_ptr<lld::File>>
 normalizedDylibToAtoms(const NormalizedFile &normalizedFile, StringRef path,
                        bool copyRefs) {
-  std::unique_ptr<MachODylibFile> file(new MachODylibFile(path));
+  std::unique_ptr<MachODylibFile> file(
+      new MachODylibFile(normalizedFile.installName));
 
   for (auto &sym : normalizedFile.globalSymbols) {
     assert((sym.scope & N_EXT) && "only expect external symbols here");

lib/ReaderWriter/MachO/MachONormalizedFileYAML.cpp

   }
 };
 
-
 template <>
 struct ScalarEnumerationTraits<RebaseType> {
   static void enumeration(IO &io, RebaseType &value) {

test/mach-o/Inputs/use-dylib-install-names.yaml

+--- !mach-o
+arch:            x86_64
+file-type:       MH_OBJECT
+flags:           [  ]
+has-UUID:        false
+OS:              unknown
+sections:
+  - segment:         __TEXT
+    section:         __text
+    type:            S_REGULAR
+    attributes:      [ S_ATTR_PURE_INSTRUCTIONS ]
+    address:         0x0000000000000000
+    content:         [ 0x55, 0x48, 0x89, 0xE5, 0xE8, 0x00, 0x00, 0x00,
+                       0x00, 0xE8, 0x00, 0x00, 0x00, 0x00, 0xE8, 0x00,
+                       0x00, 0x00, 0x00, 0xE8, 0x00, 0x00, 0x00, 0x00,
+                       0xE8, 0x00, 0x00, 0x00, 0x00, 0x5D, 0xE9, 0x00,
+                       0x00, 0x00, 0x00 ]
+global-symbols:
+  - name:            _foo
+    type:            N_SECT
+    scope:           [ N_EXT ]
+    sect:            1
+    value:           0x0000000000000000
+undefined-symbols:
+  - name:            _myGlobal
+    type:            N_UNDF
+    scope:           [ N_EXT ]
+    value:           0x0000000000000000

test/mach-o/dylib-install-names.yaml

+# RUN: lld -flavor darwin -arch x86_64 -install_name libwibble.dylib -dylib %s -o %t.dylib
+# RUN: macho-dump %t.dylib | FileCheck %s --check-prefix=CHECK-BINARY-WRITE
+# RUN: lld -flavor darwin -arch x86_64 %p/Inputs/use-dylib-install-names.yaml %t.dylib -r -print_atoms | FileCheck %s --check-prefix=CHECK-BINARY-READ
+
+--- !mach-o
+arch:            x86_64
+file-type:       MH_OBJECT
+flags:           [ MH_SUBSECTIONS_VIA_SYMBOLS ]
+has-UUID:        false
+OS:              unknown
+sections:
+  - segment:         __TEXT
+    section:         __text
+    type:            S_REGULAR
+    attributes:      [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ]
+    alignment:       4
+    address:         0x0000000000000000
+    content:         [ 0xCC, 0xC3, 0x90, 0xC3, 0x90, 0x90, 0xC3, 0x90,
+                       0x90, 0x90, 0xC3, 0x90, 0x90, 0x90, 0x90, 0xC3,
+                       0x31, 0xC0, 0xC3 ]
+local-symbols:
+  - name:            _myStatic
+    type:            N_SECT
+    sect:            1
+    value:           0x000000000000000B
+global-symbols:
+  - name:            _myGlobal
+    type:            N_SECT
+    scope:           [ N_EXT ]
+    sect:            1
+    value:           0x0000000000000001
+...
+
+
+# CHECK-BINARY-WRITE: (('command', 13)
+# CHECK-BINARY-WRITE-NEXT:  ('size', 40)
+# CHECK-BINARY-WRITE-NEXT:  ('install_name', 'libwibble.dylib')
+
+# CHECK-BINARY-READ: shared-library-atoms:
+# CHECK-BINARY-READ:     - name:          _myGlobal
+# CHECK-BINARY-READ:       load-name:     libwibble.dylib

test/mach-o/lit.local.cfg

 
 # mach-o test cases encode input files in yaml and use .yaml extension
 config.suffixes = ['.yaml']  
+config.excludes = ['Inputs']

test/mach-o/use-simple-dylib.yaml

 # RUN: lld -flavor darwin -arch x86_64 -print_atoms -r %s | FileCheck %s
-# lld -flavor darwin -arch x86_64 -print_atoms -r %s %p/Inputs/simple-dylib.yaml -o - | FileCheck %s
+
 
 --- !mach-o
 arch:            x86_64

     sect:            1
     desc:            [ N_SYMBOL_RESOLVER ]
     value:           0x0000000000000010
+
+install-name:        libspecial.dylib
 ...
 
 

 # CHECK:   - name:            _myVariablePreviouslyKnownAsPrivateExtern
 # CHECK: shared-library-atoms:
 # CHECK:   - name:            _myHidden
-# CHECK:     load-name:       {{.*}}use-simple-dylib.yaml
+# CHECK:     load-name:       libspecial.dylib
 # CHECK:   - name:            _myGlobal
-# CHECK:     load-name:       {{.*}}use-simple-dylib.yaml
+# CHECK:     load-name:       libspecial.dylib
 # CHECK:   - name:            _myHiddenWeak
-# CHECK:     load-name:       {{.*}}use-simple-dylib.yaml
+# CHECK:     load-name:       libspecial.dylib
 # CHECK:   - name:            _myGlobalWeak
-# CHECK:     load-name:       {{.*}}use-simple-dylib.yaml
+# CHECK:     load-name:       libspecial.dylib
 # CHECK:   - name:            _myResolver
-# CHECK:     load-name:       {{.*}}use-simple-dylib.yaml
+# CHECK:     load-name:       libspecial.dylib