[obj2yaml][yaml2obj] Support for MachO weak bindings

This adds support for YAML round tripping dyld info weak bindings. The storage and format of these is the same as regular bind opcodes, they are just interpreted differently by dyld.

llvm-svn: 270911

llvm/include/llvm/ObjectYAML/MachOYAML.h

@@ -74,6 +74,7 @@ struct BindOpcode {
 struct LinkEditData {
   std::vector<MachOYAML::RebaseOpcode> RebaseOpcodes;
   std::vector<MachOYAML::BindOpcode> BindOpcodes;
+  std::vector<MachOYAML::BindOpcode> WeakBindOpcodes;
 };
 
 struct Object {

llvm/lib/ObjectYAML/MachOYAML.cpp

@@ -101,6 +101,7 @@ void MappingTraits<MachOYAML::LinkEditData>::mapping(
     IO &IO, MachOYAML::LinkEditData &LinkEditData) {
   IO.mapOptional("RebaseOpcodes", LinkEditData.RebaseOpcodes);
   IO.mapOptional("BindOpcodes", LinkEditData.BindOpcodes);
+  IO.mapOptional("WeakBindOpcodes", LinkEditData.WeakBindOpcodes);
 }
 
 void MappingTraits<MachOYAML::RebaseOpcode>::mapping(

llvm/test/ObjectYAML/MachO/weak_bind_opcode.yaml

@@ -0,0 +1,133 @@
+# RUN: yaml2obj -format=macho %s | obj2yaml | FileCheck %s
+
+--- !mach-o
+FileHeader:      
+  magic:           0xFEEDFACF
+  cputype:         0x01000007
+  cpusubtype:      0x80000003
+  filetype:        0x00000002
+  ncmds:           4
+  sizeofcmds:      224
+  flags:           0x00218085
+  reserved:        0x00000000
+LoadCommands:    
+  - cmd:             LC_SEGMENT_64
+    cmdsize:         72
+    segname:         __LINKEDIT
+    vmaddr:          4294979584
+    vmsize:          4096
+    fileoff:         1024
+    filesize:        2508
+    maxprot:         7
+    initprot:        1
+    nsects:          0
+    flags:           0
+  - cmd:             LC_DYLD_INFO_ONLY
+    cmdsize:         48
+    rebase_off:      1024
+    rebase_size:     8
+    bind_off:        0
+    bind_size:       0
+    weak_bind_off:   1032
+    weak_bind_size:  96
+    lazy_bind_off:   1128
+    lazy_bind_size:  624
+    export_off:      1752
+    export_size:     48
+  - cmd:             LC_SYMTAB
+    cmdsize:         24
+    symoff:          1816
+    nsyms:           30
+    stroff:          2436
+    strsize:         1096
+  - cmd:             LC_DYSYMTAB
+    cmdsize:         80
+    ilocalsym:       0
+    nlocalsym:       9
+    iextdefsym:      9
+    nextdefsym:      2
+    iundefsym:       11
+    nundefsym:       19
+    tocoff:          0
+    ntoc:            0
+    modtaboff:       0
+    nmodtab:         0
+    extrefsymoff:    0
+    nextrefsyms:     0
+    indirectsymoff:  2296
+    nindirectsyms:   35
+    extreloff:       0
+    nextrel:         0
+    locreloff:       0
+    nlocrel:         0
+LinkEditData:    
+  WeakBindOpcodes:     
+    - Opcode:          BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
+      Imm:             1
+    - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+      Imm:             0
+      Symbol:          __ZNSt3__14coutE
+    - Opcode:          BIND_OPCODE_SET_TYPE_IMM
+      Imm:             1
+    - Opcode:          BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB
+      Imm:             2
+      ULEBExtraData:   
+        - 0x0000000000000000
+    - Opcode:          BIND_OPCODE_DO_BIND
+      Imm:             0
+    - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+      Imm:             0
+      Symbol:          __ZNSt3__15ctypeIcE2idE
+    - Opcode:          BIND_OPCODE_DO_BIND
+      Imm:             0
+    - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+      Imm:             0
+      Symbol:          ___gxx_personality_v0
+    - Opcode:          BIND_OPCODE_DO_BIND
+      Imm:             0
+    - Opcode:          BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
+      Imm:             2
+    - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+      Imm:             0
+      Symbol:          dyld_stub_binder
+    - Opcode:          BIND_OPCODE_DO_BIND
+      Imm:             0
+    - Opcode:          BIND_OPCODE_DONE
+      Imm:             0
+...
+
+#CHECK: LinkEditData:    
+#CHECK:   WeakBindOpcodes:     
+#CHECK:     - Opcode:          BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
+#CHECK:       Imm:             1
+#CHECK:     - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+#CHECK:       Imm:             0
+#CHECK:       Symbol:          __ZNSt3__14coutE
+#CHECK:     - Opcode:          BIND_OPCODE_SET_TYPE_IMM
+#CHECK:       Imm:             1
+#CHECK:     - Opcode:          BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB
+#CHECK:       Imm:             2
+#CHECK:       ULEBExtraData:   
+#CHECK:         - 0x0000000000000000
+#CHECK:     - Opcode:          BIND_OPCODE_DO_BIND
+#CHECK:       Imm:             0
+#CHECK:     - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+#CHECK:       Imm:             0
+#CHECK:       Symbol:          __ZNSt3__15ctypeIcE2idE
+#CHECK:     - Opcode:          BIND_OPCODE_DO_BIND
+#CHECK:       Imm:             0
+#CHECK:     - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+#CHECK:       Imm:             0
+#CHECK:       Symbol:          ___gxx_personality_v0
+#CHECK:     - Opcode:          BIND_OPCODE_DO_BIND
+#CHECK:       Imm:             0
+#CHECK:     - Opcode:          BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
+#CHECK:       Imm:             2
+#CHECK:     - Opcode:          BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM
+#CHECK:       Imm:             0
+#CHECK:       Symbol:          dyld_stub_binder
+#CHECK:     - Opcode:          BIND_OPCODE_DO_BIND
+#CHECK:       Imm:             0
+#CHECK:     - Opcode:          BIND_OPCODE_DONE
+#CHECK:       Imm:             0
+

llvm/tools/obj2yaml/macho2yaml.cpp

@@ -197,6 +197,8 @@ void MachODumper::dumpLoadCommands(std::unique_ptr<MachOYAML::Object> &Y) {
 void MachODumper::dumpLinkEdit(std::unique_ptr<MachOYAML::Object> &Y) {
   dumpRebaseOpcodes(Y);
   dumpBindOpcodes(Y->LinkEdit.BindOpcodes, Obj.getDyldInfoBindOpcodes());
+  dumpBindOpcodes(Y->LinkEdit.WeakBindOpcodes,
+                  Obj.getDyldInfoWeakBindOpcodes());
 }
 
 void MachODumper::dumpRebaseOpcodes(std::unique_ptr<MachOYAML::Object> &Y) {

llvm/tools/yaml2obj/yaml2macho.cpp

@@ -46,6 +46,8 @@ private:
   Error writeLoadCommands(raw_ostream &OS);
   Error writeSectionData(raw_ostream &OS);
   Error writeLinkEditData(raw_ostream &OS);
+  void writeBindOpcodes(raw_ostream &OS, uint64_t offset,
+                        std::vector<MachOYAML::BindOpcode> &BindOpcodes);
 
   void ZeroToOffset(raw_ostream &OS, size_t offset);
 
@@ -264,6 +266,27 @@ Error MachOWriter::writeSectionData(raw_ostream &OS) {
   return Error::success();
 }
 
+void MachOWriter::writeBindOpcodes(
+    raw_ostream &OS, uint64_t offset,
+    std::vector<MachOYAML::BindOpcode> &BindOpcodes) {
+  ZeroToOffset(OS, offset);
+
+  for (auto Opcode : BindOpcodes) {
+    uint8_t OpByte = Opcode.Opcode | Opcode.Imm;
+    OS.write(reinterpret_cast<char *>(&OpByte), 1);
+    for (auto Data : Opcode.ULEBExtraData) {
+      encodeULEB128(Data, OS);
+    }
+    for (auto Data : Opcode.SLEBExtraData) {
+      encodeSLEB128(Data, OS);
+    }
+    if (!Opcode.Symbol.empty()) {
+      OS.write(Opcode.Symbol.data(), Opcode.Symbol.size());
+      OS.write("\0", 1);
+    }
+  }
+}
+
 Error MachOWriter::writeLinkEditData(raw_ostream &OS) {
   MachOYAML::LinkEditData &LinkEdit = Obj.LinkEdit;
   MachO::dyld_info_command *DyldInfoOnlyCmd = 0;
@@ -289,22 +312,9 @@ Error MachOWriter::writeLinkEditData(raw_ostream &OS) {
     }
   }
 
-  ZeroToOffset(OS, DyldInfoOnlyCmd->bind_off);
+  writeBindOpcodes(OS, DyldInfoOnlyCmd->bind_off, LinkEdit.BindOpcodes);
-
+  writeBindOpcodes(OS, DyldInfoOnlyCmd->weak_bind_off,
-  for (auto Opcode : LinkEdit.BindOpcodes) {
+                   LinkEdit.WeakBindOpcodes);
-    uint8_t OpByte = Opcode.Opcode | Opcode.Imm;
-    OS.write(reinterpret_cast<char *>(&OpByte), 1);
-    for (auto Data : Opcode.ULEBExtraData) {
-      encodeULEB128(Data, OS);
-    }
-    for (auto Data : Opcode.SLEBExtraData) {
-      encodeSLEB128(Data, OS);
-    }
-    if(!Opcode.Symbol.empty()) {
-      OS.write(Opcode.Symbol.data(), Opcode.Symbol.size());
-      OS.write("\0", 1);
-    }
-  }
 
   // Fill to the end of the string table
   ZeroToOffset(OS, SymtabCmd->stroff + SymtabCmd->strsize);