From efdbec8b0a49fb67c3844be703548fdc6c1dded0 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 30 Jan 2014 02:49:50 +0000
Subject: Simplify the handling of iterators in ObjectFile.

None of the object file formats reported error on iterator increment. In
retrospect, that is not too surprising: no object format stores symbols or
sections in a linked list or other structure that requires chasing pointers.
As a consequence, all error checking can be done on begin() and end().

This reduces the text segment of bin/llvm-readobj in my machine from 521233 to
518526 bytes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200442 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp    | 24 +++++++++-------------
 lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp | 13 ++++--------
 2 files changed, 14 insertions(+), 23 deletions(-)

(limited to 'lib/ExecutionEngine')

diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index f99d7d0b27..6f9eefb68c 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -115,12 +115,10 @@ ObjectImage *RuntimeDyldImpl::loadObject(ObjectImage *InputObject) {
   // Maximum required total memory to allocate all common symbols
   uint64_t CommonSize = 0;
 
-  error_code err;
   // Parse symbols
   DEBUG(dbgs() << "Parse symbols:\n");
-  for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols();
-       i != e; i.increment(err)) {
-    Check(err);
+  for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols(); i != e;
+       ++i) {
     object::SymbolRef::Type SymType;
     StringRef Name;
     Check(i->getType(SymType));
@@ -173,18 +171,16 @@ ObjectImage *RuntimeDyldImpl::loadObject(ObjectImage *InputObject) {
 
   // Parse and process relocations
   DEBUG(dbgs() << "Parse relocations:\n");
-  for (section_iterator si = obj->begin_sections(),
-       se = obj->end_sections(); si != se; si.increment(err)) {
-    Check(err);
+  for (section_iterator si = obj->begin_sections(), se = obj->end_sections();
+       si != se; ++si) {
     bool isFirstRelocation = true;
     unsigned SectionID = 0;
     StubMap Stubs;
     section_iterator RelocatedSection = si->getRelocatedSection();
 
     for (relocation_iterator i = si->begin_relocations(),
-         e = si->end_relocations(); i != e; i.increment(err)) {
-      Check(err);
-
+                             e = si->end_relocations();
+         i != e; ++i) {
       // If it's the first relocation in this section, find its SectionID
       if (isFirstRelocation) {
         SectionID =
@@ -251,21 +247,21 @@ unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
 
   unsigned StubBufSize = 0,
            StubSize = getMaxStubSize();
-  error_code err;
   const ObjectFile *ObjFile = Obj.getObjectFile();
   // FIXME: this is an inefficient way to handle this. We should computed the
   // necessary section allocation size in loadObject by walking all the sections
   // once.
   if (StubSize > 0) {
     for (section_iterator SI = ObjFile->begin_sections(),
-           SE = ObjFile->end_sections();
-         SI != SE; SI.increment(err), Check(err)) {
+                          SE = ObjFile->end_sections();
+         SI != SE; ++SI) {
       section_iterator RelSecI = SI->getRelocatedSection();
       if (!(RelSecI == Section))
         continue;
 
       for (relocation_iterator I = SI->begin_relocations(),
-             E = SI->end_relocations(); I != E; I.increment(err), Check(err)) {
+                               E = SI->end_relocations();
+           I != E; ++I) {
         StubBufSize += StubSize;
       }
     }
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index 7f3a790d4b..4dbd6794c6 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -621,10 +621,8 @@ void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
                                          RelocationValueRef &Rel) {
   // Get the ELF symbol value (st_value) to compare with Relocation offset in
   // .opd entries
-
-  error_code err;
-  for (section_iterator si = Obj.begin_sections(),
-     se = Obj.end_sections(); si != se; si.increment(err)) {
+  for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
+       si != se; ++si) {
     section_iterator RelSecI = si->getRelocatedSection();
     if (RelSecI == Obj.end_sections())
       continue;
@@ -636,14 +634,12 @@ void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
 
     for (relocation_iterator i = si->begin_relocations(),
          e = si->end_relocations(); i != e;) {
-      check(err);
-
       // The R_PPC64_ADDR64 relocation indicates the first field
       // of a .opd entry
       uint64_t TypeFunc;
       check(i->getType(TypeFunc));
       if (TypeFunc != ELF::R_PPC64_ADDR64) {
-        i.increment(err);
+        ++i;
         continue;
       }
 
@@ -653,10 +649,9 @@ void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
       int64_t Addend;
       check(getELFRelocationAddend(*i, Addend));
 
-      i = i.increment(err);
+      ++i;
       if (i == e)
         break;
-      check(err);
 
       // Just check if following relocation is a R_PPC64_TOC
       uint64_t TypeTOC;
-- 
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