[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

llvm-svn: 203799
diff --git a/llvm/lib/MC/MCObjectDisassembler.cpp b/llvm/lib/MC/MCObjectDisassembler.cpp
index 5851bdf..2cd7031 100644
--- a/llvm/lib/MC/MCObjectDisassembler.cpp
+++ b/llvm/lib/MC/MCObjectDisassembler.cpp
@@ -87,20 +87,24 @@
 }
 
 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 @@
       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 @@
     : 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/llvm/lib/MC/MCObjectSymbolizer.cpp b/llvm/lib/MC/MCObjectSymbolizer.cpp
index 8aafcf6..4548a7d 100644
--- a/llvm/lib/MC/MCObjectSymbolizer.cpp
+++ b/llvm/lib/MC/MCObjectSymbolizer.cpp
@@ -51,11 +51,11 @@
     : 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 @@
 }
 
 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,