[Object, MachO] Introduce MachOObjectFile::load_commands() range iterator.

Summary:
Now users don't have to manually deal with getFirstLoadCommandInfo() /
getNextLoadCommandInfo(), calculate the number of load segments, etc.

No functionality change.

Test Plan: regression test suite

Reviewers: rafael, lhames, loladiro

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10144

llvm-svn: 238983

1 files changed, 18 insertions, 65 deletions

diff --git a/llvm/tools/llvm-objdump/MachODump.cpp b/llvm/tools/llvm-objdump/MachODump.cpp
index c5590d2eaf8..f5e39fc073d 100644
--- a/llvm/tools/llvm-objdump/MachODump.cpp
+++ b/llvm/tools/llvm-objdump/MachODump.cpp
@@ -281,8 +281,7 @@ static uint64_t DumpDataInCode(const uint8_t *bytes, uint64_t Length,
   return Size;
 }
 
-static void getSectionsAndSymbols(const MachO::mach_header Header,
-                                  MachOObjectFile *MachOObj,
+static void getSectionsAndSymbols(MachOObjectFile *MachOObj,
                                   std::vector<SectionRef> &Sections,
                                   std::vector<SymbolRef> &Symbols,
                                   SmallVectorImpl<uint64_t> &FoundFns,
@@ -300,10 +299,8 @@ static void getSectionsAndSymbols(const MachO::mach_header Header,
     Sections.push_back(Section);
   }
 
-  MachOObjectFile::LoadCommandInfo Command =
-      MachOObj->getFirstLoadCommandInfo();
   bool BaseSegmentAddressSet = false;
-  for (unsigned i = 0;; ++i) {
+  for (const auto &Command : MachOObj->load_commands()) {
     if (Command.C.cmd == MachO::LC_FUNCTION_STARTS) {
       // We found a function starts segment, parse the addresses for later
       // consumption.
@@ -319,11 +316,6 @@ static void getSectionsAndSymbols(const MachO::mach_header Header,
         BaseSegmentAddress = SLC.vmaddr;
       }
     }
-
-    if (i == Header.ncmds - 1)
-      break;
-    else
-      Command = MachOObj->getNextLoadCommandInfo(Command);
   }
 }
 
@@ -386,9 +378,7 @@ static void PrintIndirectSymbolTable(MachOObjectFile *O, bool verbose,
 }
 
 static void PrintIndirectSymbols(MachOObjectFile *O, bool verbose) {
-  uint32_t LoadCommandCount = O->getHeader().ncmds;
-  MachOObjectFile::LoadCommandInfo Load = O->getFirstLoadCommandInfo();
-  for (unsigned I = 0;; ++I) {
+  for (const auto &Load : O->load_commands()) {
     if (Load.C.cmd == MachO::LC_SEGMENT_64) {
       MachO::segment_command_64 Seg = O->getSegment64LoadCommand(Load);
       for (unsigned J = 0; J < Seg.nsects; ++J) {
@@ -446,10 +436,6 @@ static void PrintIndirectSymbols(MachOObjectFile *O, bool verbose) {
         }
       }
     }
-    if (I == LoadCommandCount - 1)
-      break;
-    else
-      Load = O->getNextLoadCommandInfo(Load);
   }
 }
 
@@ -553,9 +539,8 @@ static void PrintLinkOptHints(MachOObjectFile *O) {
 }
 
 static void PrintDylibs(MachOObjectFile *O, bool JustId) {
-  uint32_t LoadCommandCount = O->getHeader().ncmds;
-  MachOObjectFile::LoadCommandInfo Load = O->getFirstLoadCommandInfo();
-  for (unsigned I = 0;; ++I) {
+  unsigned Index = 0;
+  for (const auto &Load : O->load_commands()) {
     if ((JustId && Load.C.cmd == MachO::LC_ID_DYLIB) ||
         (!JustId && (Load.C.cmd == MachO::LC_ID_DYLIB ||
                      Load.C.cmd == MachO::LC_LOAD_DYLIB ||
@@ -595,13 +580,9 @@ static void PrintDylibs(MachOObjectFile *O, bool JustId) {
           outs() << "LC_LOAD_UPWARD_DYLIB ";
         else
           outs() << "LC_??? ";
-        outs() << "command " << I << "\n";
+        outs() << "command " << Index++ << "\n";
       }
     }
-    if (I == LoadCommandCount - 1)
-      break;
-    else
-      Load = O->getNextLoadCommandInfo(Load);
   }
 }
 
@@ -2132,9 +2113,7 @@ static int SymbolizerGetOpInfo(void *DisInfo, uint64_t Pc, uint64_t Offset,
 // it returns a pointer to that string.  Else it returns nullptr.
 static const char *GuessCstringPointer(uint64_t ReferenceValue,
                                        struct DisassembleInfo *info) {
-  uint32_t LoadCommandCount = info->O->getHeader().ncmds;
-  MachOObjectFile::LoadCommandInfo Load = info->O->getFirstLoadCommandInfo();
-  for (unsigned I = 0;; ++I) {
+  for (const auto &Load : info->O->load_commands()) {
     if (Load.C.cmd == MachO::LC_SEGMENT_64) {
       MachO::segment_command_64 Seg = info->O->getSegment64LoadCommand(Load);
       for (unsigned J = 0; J < Seg.nsects; ++J) {
@@ -2178,10 +2157,6 @@ static const char *GuessCstringPointer(uint64_t ReferenceValue,
         }
       }
     }
-    if (I == LoadCommandCount - 1)
-      break;
-    else
-      Load = info->O->getNextLoadCommandInfo(Load);
   }
   return nullptr;
 }
@@ -2192,11 +2167,9 @@ static const char *GuessCstringPointer(uint64_t ReferenceValue,
 // symbol name being referenced by the stub or pointer.
 static const char *GuessIndirectSymbol(uint64_t ReferenceValue,
                                        struct DisassembleInfo *info) {
-  uint32_t LoadCommandCount = info->O->getHeader().ncmds;
-  MachOObjectFile::LoadCommandInfo Load = info->O->getFirstLoadCommandInfo();
   MachO::dysymtab_command Dysymtab = info->O->getDysymtabLoadCommand();
   MachO::symtab_command Symtab = info->O->getSymtabLoadCommand();
-  for (unsigned I = 0;; ++I) {
+  for (const auto &Load : info->O->load_commands()) {
     if (Load.C.cmd == MachO::LC_SEGMENT_64) {
       MachO::segment_command_64 Seg = info->O->getSegment64LoadCommand(Load);
       for (unsigned J = 0; J < Seg.nsects; ++J) {
@@ -2266,10 +2239,6 @@ static const char *GuessIndirectSymbol(uint64_t ReferenceValue,
         }
       }
     }
-    if (I == LoadCommandCount - 1)
-      break;
-    else
-      Load = info->O->getNextLoadCommandInfo(Load);
   }
   return nullptr;
 }
@@ -2356,9 +2325,7 @@ static uint64_t GuessPointerPointer(uint64_t ReferenceValue,
   selref = false;
   msgref = false;
   cfstring = false;
-  uint32_t LoadCommandCount = info->O->getHeader().ncmds;
-  MachOObjectFile::LoadCommandInfo Load = info->O->getFirstLoadCommandInfo();
-  for (unsigned I = 0;; ++I) {
+  for (const auto &Load : info->O->load_commands()) {
     if (Load.C.cmd == MachO::LC_SEGMENT_64) {
       MachO::segment_command_64 Seg = info->O->getSegment64LoadCommand(Load);
       for (unsigned J = 0; J < Seg.nsects; ++J) {
@@ -2403,10 +2370,6 @@ static uint64_t GuessPointerPointer(uint64_t ReferenceValue,
       }
     }
     // TODO: Look for LC_SEGMENT for 32-bit Mach-O files.
-    if (I == LoadCommandCount - 1)
-      break;
-    else
-      Load = info->O->getNextLoadCommandInfo(Load);
   }
   return 0;
 }
@@ -6075,7 +6038,7 @@ static void DisassembleMachO(StringRef Filename, MachOObjectFile *MachOOF,
   SmallVector<uint64_t, 8> FoundFns;
   uint64_t BaseSegmentAddress;
 
-  getSectionsAndSymbols(Header, MachOOF, Sections, Symbols, FoundFns,
+  getSectionsAndSymbols(MachOOF, Sections, Symbols, FoundFns,
                         BaseSegmentAddress);
 
   // Sort the symbols by address, just in case they didn't come in that way.
@@ -8367,15 +8330,12 @@ static void PrintLinkEditDataCommand(MachO::linkedit_data_command ld,
     outs() << "\n";
 }
 
-static void PrintLoadCommands(const MachOObjectFile *Obj, uint32_t ncmds,
-                              uint32_t filetype, uint32_t cputype,
-                              bool verbose) {
-  if (ncmds == 0)
-    return;
+static void PrintLoadCommands(const MachOObjectFile *Obj, uint32_t filetype,
+                              uint32_t cputype, bool verbose) {
   StringRef Buf = Obj->getData();
-  MachOObjectFile::LoadCommandInfo Command = Obj->getFirstLoadCommandInfo();
-  for (unsigned i = 0;; ++i) {
-    outs() << "Load command " << i << "\n";
+  unsigned Index = 0;
+  for (const auto &Command : Obj->load_commands()) {
+    outs() << "Load command " << Index++ << "\n";
     if (Command.C.cmd == MachO::LC_SEGMENT) {
       MachO::segment_command SLC = Obj->getSegmentLoadCommand(Command);
       const char *sg_segname = SLC.segname;
@@ -8494,14 +8454,10 @@ static void PrintLoadCommands(const MachOObjectFile *Obj, uint32_t ncmds,
       // TODO: get and print the raw bytes of the load command.
     }
     // TODO: print all the other kinds of load commands.
-    if (i == ncmds - 1)
-      break;
-    else
-      Command = Obj->getNextLoadCommandInfo(Command);
   }
 }
 
-static void getAndPrintMachHeader(const MachOObjectFile *Obj, uint32_t &ncmds,
+static void getAndPrintMachHeader(const MachOObjectFile *Obj,
                                   uint32_t &filetype, uint32_t &cputype,
                                   bool verbose) {
   if (Obj->is64Bit()) {
@@ -8509,7 +8465,6 @@ static void getAndPrintMachHeader(const MachOObjectFile *Obj, uint32_t &ncmds,
     H_64 = Obj->getHeader64();
     PrintMachHeader(H_64.magic, H_64.cputype, H_64.cpusubtype, H_64.filetype,
                     H_64.ncmds, H_64.sizeofcmds, H_64.flags, verbose);
-    ncmds = H_64.ncmds;
     filetype = H_64.filetype;
     cputype = H_64.cputype;
   } else {
@@ -8517,7 +8472,6 @@ static void getAndPrintMachHeader(const MachOObjectFile *Obj, uint32_t &ncmds,
     H = Obj->getHeader();
     PrintMachHeader(H.magic, H.cputype, H.cpusubtype, H.filetype, H.ncmds,
                     H.sizeofcmds, H.flags, verbose);
-    ncmds = H.ncmds;
     filetype = H.filetype;
     cputype = H.cputype;
   }
@@ -8525,11 +8479,10 @@ static void getAndPrintMachHeader(const MachOObjectFile *Obj, uint32_t &ncmds,
 
 void llvm::printMachOFileHeader(const object::ObjectFile *Obj) {
   const MachOObjectFile *file = dyn_cast<const MachOObjectFile>(Obj);
-  uint32_t ncmds = 0;
   uint32_t filetype = 0;
   uint32_t cputype = 0;
-  getAndPrintMachHeader(file, ncmds, filetype, cputype, !NonVerbose);
-  PrintLoadCommands(file, ncmds, filetype, cputype, !NonVerbose);
+  getAndPrintMachHeader(file, filetype, cputype, !NonVerbose);
+  PrintLoadCommands(file, filetype, cputype, !NonVerbose);
 }
 
 //===----------------------------------------------------------------------===//