[C++11] Introduce ObjectFile::sections().

Summary:
This adds ObjectFile::section_iterator_range, that allows to write
range-based for-loops running over all sections of a given file.
Several files from lib/ are converted to the new interface. Similar fixes
should be applied to a variety of llvm-* tools.

Reviewers: rafael

Reviewed By: rafael

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3069

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203799 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 63 insertions, 55 deletions

diff --git a/include/llvm/Object/ObjectFile.h b/include/llvm/Object/ObjectFile.h
index d39a9423e0..a3301dbe43 100644
--- a/include/llvm/Object/ObjectFile.h
+++ b/include/llvm/Object/ObjectFile.h
@@ -289,6 +289,11 @@ public:
   virtual section_iterator section_begin() const = 0;
   virtual section_iterator section_end() const = 0;
 
+  typedef iterator_range<section_iterator> section_iterator_range;
+  section_iterator_range sections() const {
+    return section_iterator_range(section_begin(), section_end());
+  }
+
   virtual library_iterator needed_library_begin() const = 0;
   virtual library_iterator needed_library_end() const = 0;
 
diff --git a/lib/DebugInfo/DWARFContext.cpp b/lib/DebugInfo/DWARFContext.cpp
index 94935e2568..8a245a0301 100644
--- a/lib/DebugInfo/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARFContext.cpp
@@ -605,16 +605,14 @@ static bool consumeCompressedDebugSectionHeader(StringRef &data,
   return true;
 }
 
-DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
-  IsLittleEndian(Obj->isLittleEndian()),
-  AddressSize(Obj->getBytesInAddress()) {
-  for (object::section_iterator i = Obj->section_begin(),
-                                e = Obj->section_end();
-       i != e; ++i) {
+DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj)
+    : IsLittleEndian(Obj->isLittleEndian()),
+      AddressSize(Obj->getBytesInAddress()) {
+  for (const SectionRef &Section : Obj->sections()) {
     StringRef name;
-    i->getName(name);
+    Section.getName(name);
     StringRef data;
-    i->getContents(data);
+    Section.getContents(data);
 
     name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
 
@@ -634,7 +632,7 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
       UncompressedSections.push_back(std::move(UncompressedSection));
     }
 
-    StringRef *Section =
+    StringRef *SectionData =
         StringSwitch<StringRef *>(name)
             .Case("debug_info", &InfoSection.Data)
             .Case("debug_abbrev", &AbbrevSection)
@@ -656,8 +654,8 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
             .Case("debug_addr", &AddrSection)
             // Any more debug info sections go here.
             .Default(0);
-    if (Section) {
-      *Section = data;
+    if (SectionData) {
+      *SectionData = data;
       if (name == "debug_ranges") {
         // FIXME: Use the other dwo range section when we emit it.
         RangeDWOSection = data;
@@ -665,12 +663,12 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
     } else if (name == "debug_types") {
       // Find debug_types data by section rather than name as there are
       // multiple, comdat grouped, debug_types sections.
-      TypesSections[*i].Data = data;
+      TypesSections[Section].Data = data;
     } else if (name == "debug_types.dwo") {
-      TypesDWOSections[*i].Data = data;
+      TypesDWOSections[Section].Data = data;
     }
 
-    section_iterator RelocatedSection = i->getRelocatedSection();
+    section_iterator RelocatedSection = Section.getRelocatedSection();
     if (RelocatedSection == Obj->section_end())
       continue;
 
@@ -698,11 +696,11 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
         continue;
     }
 
-    if (i->relocation_begin() != i->relocation_end()) {
+    if (Section.relocation_begin() != Section.relocation_end()) {
       uint64_t SectionSize;
       RelocatedSection->getSize(SectionSize);
-      for (object::relocation_iterator reloc_i = i->relocation_begin(),
-                                       reloc_e = i->relocation_end();
+      for (object::relocation_iterator reloc_i = Section.relocation_begin(),
+                                       reloc_e = Section.relocation_end();
            reloc_i != reloc_e; ++reloc_i) {
         uint64_t Address;
         reloc_i->getOffset(Address);
diff --git a/lib/MC/MCObjectDisassembler.cpp b/lib/MC/MCObjectDisassembler.cpp
index 5851bdfdb7..2cd7031f82 100644
--- a/lib/MC/MCObjectDisassembler.cpp
+++ b/lib/MC/MCObjectDisassembler.cpp
@@ -87,20 +87,24 @@ MCModule *MCObjectDisassembler::buildModule(bool withCFG) {
 }
 
 void MCObjectDisassembler::buildSectionAtoms(MCModule *Module) {
-  for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
-       SI != SE; ++SI) {
-    bool isText; SI->isText(isText);
-    bool isData; SI->isData(isData);
+  for (const SectionRef &Section : Obj.sections()) {
+    bool isText;
+    Section.isText(isText);
+    bool isData;
+    Section.isData(isData);
     if (!isData && !isText)
       continue;
 
-    uint64_t StartAddr; SI->getAddress(StartAddr);
-    uint64_t SecSize; SI->getSize(SecSize);
+    uint64_t StartAddr;
+    Section.getAddress(StartAddr);
+    uint64_t SecSize;
+    Section.getSize(SecSize);
     if (StartAddr == UnknownAddressOrSize || SecSize == UnknownAddressOrSize)
       continue;
     StartAddr = getEffectiveLoadAddr(StartAddr);
 
-    StringRef Contents; SI->getContents(Contents);
+    StringRef Contents;
+    Section.getContents(Contents);
     StringRefMemoryObject memoryObject(Contents, StartAddr);
 
     // We don't care about things like non-file-backed sections yet.
@@ -108,7 +112,8 @@ void MCObjectDisassembler::buildSectionAtoms(MCModule *Module) {
       continue;
     uint64_t EndAddr = StartAddr + SecSize - 1;
 
-    StringRef SecName; SI->getName(SecName);
+    StringRef SecName;
+    Section.getName(SecName);
 
     if (isText) {
       MCTextAtom *Text = 0;
@@ -495,17 +500,16 @@ MCMachOObjectDisassembler::MCMachOObjectDisassembler(
     : MCObjectDisassembler(MOOF, Dis, MIA), MOOF(MOOF),
       VMAddrSlide(VMAddrSlide), HeaderLoadAddress(HeaderLoadAddress) {
 
-  for (section_iterator SI = MOOF.section_begin(), SE = MOOF.section_end();
-       SI != SE; ++SI) {
+  for (const SectionRef &Section : MOOF.sections()) {
     StringRef Name;
-    SI->getName(Name);
+    Section.getName(Name);
     // FIXME: We should use the S_ section type instead of the name.
     if (Name == "__mod_init_func") {
       DEBUG(dbgs() << "Found __mod_init_func section!\n");
-      SI->getContents(ModInitContents);
+      Section.getContents(ModInitContents);
     } else if (Name == "__mod_exit_func") {
       DEBUG(dbgs() << "Found __mod_exit_func section!\n");
-      SI->getContents(ModExitContents);
+      Section.getContents(ModExitContents);
     }
   }
 }
diff --git a/lib/MC/MCObjectSymbolizer.cpp b/lib/MC/MCObjectSymbolizer.cpp
index 8aafcf6ee7..4548a7d425 100644
--- a/lib/MC/MCObjectSymbolizer.cpp
+++ b/lib/MC/MCObjectSymbolizer.cpp
@@ -51,11 +51,11 @@ MCMachObjectSymbolizer::MCMachObjectSymbolizer(
     : MCObjectSymbolizer(Ctx, RelInfo, MOOF), MOOF(MOOF), StubsStart(0),
       StubsCount(0), StubSize(0), StubsIndSymIndex(0) {
 
-  for (section_iterator SI = MOOF->section_begin(), SE = MOOF->section_end();
-       SI != SE; ++SI) {
-    StringRef Name; SI->getName(Name);
+  for (const SectionRef &Section : MOOF->sections()) {
+    StringRef Name;
+    Section.getName(Name);
     if (Name == "__stubs") {
-      SectionRef StubsSec = *SI;
+      SectionRef StubsSec = Section;
       if (MOOF->is64Bit()) {
         MachO::section_64 S = MOOF->getSection64(StubsSec.getRawDataRefImpl());
         StubsIndSymIndex = S.reserved1;
@@ -230,40 +230,41 @@ const RelocationRef *MCObjectSymbolizer::findRelocationAt(uint64_t Addr) {
 }
 
 void MCObjectSymbolizer::buildSectionList() {
-  for (section_iterator SI = Obj->section_begin(), SE = Obj->section_end();
-       SI != SE; ++SI) {
-    bool RequiredForExec; SI->isRequiredForExecution(RequiredForExec);
+  for (const SectionRef &Section : Obj->sections()) {
+    bool RequiredForExec;
+    Section.isRequiredForExecution(RequiredForExec);
     if (RequiredForExec == false)
       continue;
-    uint64_t SAddr; SI->getAddress(SAddr);
-    uint64_t SSize; SI->getSize(SSize);
-    SortedSectionList::iterator It = std::lower_bound(SortedSections.begin(),
-                                                      SortedSections.end(),
-                                                      SAddr,
-                                                      SectionStartsBefore);
+    uint64_t SAddr;
+    Section.getAddress(SAddr);
+    uint64_t SSize;
+    Section.getSize(SSize);
+    SortedSectionList::iterator It =
+        std::lower_bound(SortedSections.begin(), SortedSections.end(), SAddr,
+                         SectionStartsBefore);
     if (It != SortedSections.end()) {
       uint64_t FoundSAddr; It->getAddress(FoundSAddr);
       if (FoundSAddr < SAddr + SSize)
         llvm_unreachable("Inserting overlapping sections");
     }
-    SortedSections.insert(It, *SI);
+    SortedSections.insert(It, Section);
   }
 }
 
 void MCObjectSymbolizer::buildRelocationByAddrMap() {
-  for (section_iterator SI = Obj->section_begin(), SE = Obj->section_end();
-       SI != SE; ++SI) {
-    section_iterator RelSecI = SI->getRelocatedSection();
+  for (const SectionRef &Section : Obj->sections()) {
+    section_iterator RelSecI = Section.getRelocatedSection();
     if (RelSecI == Obj->section_end())
       continue;
 
     uint64_t StartAddr; RelSecI->getAddress(StartAddr);
     uint64_t Size; RelSecI->getSize(Size);
-    bool RequiredForExec; RelSecI->isRequiredForExecution(RequiredForExec);
+    bool RequiredForExec;
+    RelSecI->isRequiredForExecution(RequiredForExec);
     if (RequiredForExec == false || Size == 0)
       continue;
-    for (relocation_iterator RI = SI->relocation_begin(),
-                             RE = SI->relocation_end();
+    for (relocation_iterator RI = Section.relocation_begin(),
+                             RE = Section.relocation_end();
          RI != RE; ++RI) {
       // FIXME: libObject is inconsistent regarding error handling. The
       // overwhelming majority of methods always return object_error::success,
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 5dd9e5596b..fb8a214679 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -313,16 +313,16 @@ static void printRelocationTargetName(const MachOObjectFile *O,
 
     // If we couldn't find a symbol that this relocation refers to, try
     // to find a section beginning instead.
-    for (section_iterator SI = O->section_begin(), SE = O->section_end();
-         SI != SE; ++SI) {
+    for (const SectionRef &Section : O->sections()) {
       error_code ec;
       uint64_t Addr;
       StringRef Name;
 
-      if ((ec = SI->getAddress(Addr)))
+      if ((ec = Section.getAddress(Addr)))
         report_fatal_error(ec.message());
-      if (Addr != Val) continue;
-      if ((ec = SI->getName(Name)))
+      if (Addr != Val)
+        continue;
+      if ((ec = Section.getName(Name)))
         report_fatal_error(ec.message());
       fmt << Name;
       return;