Add a (nonfunctional) -dyld_info flag to llvm-objdump.

Darwin otool implements this flag as a one-stop solution for
displaying bind and rebase info. As I am working on upstreaming
chained fixup support this command will be useful to write testcases.

Differential Revision: https://reviews.llvm.org/D113573

llvm/docs/CommandGuide/llvm-objdump.rst

@@ -302,6 +302,11 @@ MACH-O ONLY OPTIONS AND COMMANDS
 
   Disassemble just the specified symbol's instructions.
 
+.. option:: --dyld_info
+
+  Print bind and rebase information used by dyld to resolve external
+  references in a final linked binary.
+
 .. option:: --dylibs-used
 
   Display the shared libraries used for linked files.

llvm/test/tools/llvm-objdump/MachO/dyld_info.test

@@ -0,0 +1,7 @@
+RUN: llvm-objdump --macho --dyld_info %p/Inputs/bind.macho-x86_64 \
+RUN:   | FileCheck %s --match-full-lines --strict-whitespace \
+RUN:     --implicit-check-not={{.}}
+
+CHECK:{{.*}}bind.macho-x86_64:
+CHECK-NEXT:dyld information:
+CHECK-NEXT:[not yet implemented].

llvm/tools/llvm-objdump/MachODump.cpp

@@ -81,6 +81,7 @@ bool objdump::DataInCode;
 bool objdump::FunctionStarts;
 bool objdump::LinkOptHints;
 bool objdump::InfoPlist;
+bool objdump::DyldInfo;
 bool objdump::DylibsUsed;
 bool objdump::DylibId;
 bool objdump::Verbose;
@@ -111,6 +112,7 @@ void objdump::parseMachOOptions(const llvm::opt::InputArgList &InputArgs) {
   FunctionStarts = InputArgs.hasArg(OBJDUMP_function_starts);
   LinkOptHints = InputArgs.hasArg(OBJDUMP_link_opt_hints);
   InfoPlist = InputArgs.hasArg(OBJDUMP_info_plist);
+  DyldInfo = InputArgs.hasArg(OBJDUMP_dyld_info);
   DylibsUsed = InputArgs.hasArg(OBJDUMP_dylibs_used);
   DylibId = InputArgs.hasArg(OBJDUMP_dylib_id);
   Verbose = !InputArgs.hasArg(OBJDUMP_non_verbose);
@@ -1182,6 +1184,11 @@ static void PrintLinkOptHints(MachOObjectFile *O) {
   }
 }
 
+static void PrintDyldInfo(MachOObjectFile *O) {
+  outs() << "dyld information:\n";
+  outs() << "[not yet implemented].\n";
+}
+
 static void PrintDylibs(MachOObjectFile *O, bool JustId) {
   unsigned Index = 0;
   for (const auto &Load : O->load_commands()) {
@@ -1900,8 +1907,8 @@ static void ProcessMachO(StringRef Name, MachOObjectFile *MachOOF,
   // UniversalHeaders or ArchiveHeaders.
   if (Disassemble || Relocations || PrivateHeaders || ExportsTrie || Rebase ||
       Bind || SymbolTable || LazyBind || WeakBind || IndirectSymbols ||
-      DataInCode || FunctionStarts || LinkOptHints || DylibsUsed || DylibId ||
-      Rpaths || ObjcMetaData || (!FilterSections.empty())) {
+      DataInCode || FunctionStarts || LinkOptHints || DyldInfo || DylibsUsed ||
+      DylibId || Rpaths || ObjcMetaData || (!FilterSections.empty())) {
     if (LeadingHeaders) {
       outs() << Name;
       if (!ArchiveMemberName.empty())
@@ -1970,6 +1977,8 @@ static void ProcessMachO(StringRef Name, MachOObjectFile *MachOOF,
     DumpSectionContents(FileName, MachOOF, Verbose);
   if (InfoPlist)
     DumpInfoPlistSectionContents(FileName, MachOOF);
+  if (DyldInfo)
+    PrintDyldInfo(MachOOF);
   if (DylibsUsed)
     PrintDylibs(MachOOF, false);
   if (DylibId)

llvm/tools/llvm-objdump/MachODump.h

@@ -36,6 +36,7 @@ void parseMachOOptions(const llvm::opt::InputArgList &InputArgs);
 extern bool Bind;
 extern bool DataInCode;
 extern std::string DisSymName;
+extern bool DyldInfo;
 extern bool DylibId;
 extern bool DylibsUsed;
 extern bool ExportsTrie;

llvm/tools/llvm-objdump/ObjdumpOpts.td

@@ -296,6 +296,12 @@ def info_plist : Flag<["--"], "info-plist">,
            "Mach-O objects (requires --macho)">,
   Group<grp_mach_o>;
 
+def dyld_info : Flag<["--"], "dyld_info">,
+      HelpText<"Print bind and rebase information used by dyld to resolve "
+               "external references in a final linked binary "
+               "(requires --macho)">,
+      Group<grp_mach_o>;
+
 def dylibs_used : Flag<["--"], "dylibs-used">,
   HelpText<"Print the shared libraries used for linked "
            "Mach-O files (requires --macho)">,

llvm/tools/llvm-objdump/OtoolOpts.td

@@ -47,7 +47,6 @@ def X : Flag<["-"], "X">, HelpText<"omit leading addresses or headers">;
 // -addr_slide=arg
 // -function_offsets
 
-
 // Obsolete and unsupported:
 def grp_obsolete : OptionGroup<"kind">,
   HelpText<"Obsolete and unsupported flags">;

llvm/tools/llvm-objdump/llvm-objdump.cpp

@@ -2760,11 +2760,11 @@ int main(int argc, char **argv) {
       !DynamicRelocations && !FileHeaders && !PrivateHeaders && !RawClangAST &&
       !Relocations && !SectionHeaders && !SectionContents && !SymbolTable &&
       !DynamicSymbolTable && !UnwindInfo && !FaultMapSection &&
-      !(MachOOpt &&
-        (Bind || DataInCode || DylibId || DylibsUsed || ExportsTrie ||
-         FirstPrivateHeader || FunctionStarts || IndirectSymbols || InfoPlist ||
-         LazyBind || LinkOptHints || ObjcMetaData || Rebase || Rpaths ||
-         UniversalHeaders || WeakBind || !FilterSections.empty()))) {
+      !(MachOOpt && (Bind || DataInCode || DyldInfo || DylibId || DylibsUsed ||
+                     ExportsTrie || FirstPrivateHeader || FunctionStarts ||
+                     IndirectSymbols || InfoPlist || LazyBind || LinkOptHints ||
+                     ObjcMetaData || Rebase || Rpaths || UniversalHeaders ||
+                     WeakBind || !FilterSections.empty()))) {
     T->printHelp(ToolName);
     return 2;
   }