From 4c511cd88fa3bd986227122f36af6fbcdceb2b33 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Sun, 17 Aug 2014 16:31:39 +0000
Subject: [PATCH] Fix an off-by-one bug in the target independent llvm-objdump.

It would prevent the display of a single byte instruction before a label.

Patch by Steve King!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215837 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Object/Inputs/trivial-label-test.elf-x86-64 | Bin 0 -> 741 bytes
 test/Object/X86/objdump-label.test               |  10 ++++++++++
 tools/llvm-objdump/llvm-objdump.cpp              |  15 +++++----------
 3 files changed, 15 insertions(+), 10 deletions(-)
 create mode 100644 test/Object/Inputs/trivial-label-test.elf-x86-64
 create mode 100644 test/Object/X86/objdump-label.test

diff --git a/test/Object/Inputs/trivial-label-test.elf-x86-64 b/test/Object/Inputs/trivial-label-test.elf-x86-64
new file mode 100644
index 0000000000000000000000000000000000000000..76f4499a834415d76ea6b21e63bdf91f24eb198e
GIT binary patch
literal 741
zcmb<-^>JfjWMpQ50!9Wq21XbMi7r55JAl~^4D1Xn3=<{*IeI0j6(tOMNyWtsdc_&V
zB}FBPNkA5iuFM7VQxZ!OkxU_v333|<v!Q8sfbyBp#97ezYCt|nKitDmc^5QwFfO`&
zcAx|Y5R<E)2a8^iT`>D~KpZ3haw{^B19H&)2$DB|3a)@E289pItso%@sJIxAMt3_%
z>IPIlFH{|jLbo3#j!v_J1sE~X4kr$Ah`HEJXT~rEVjDA7pM(5^#YbuR`3y;kMGQ%$
GxeNfJK^dU{

literal 0
HcmV?d00001

diff --git a/test/Object/X86/objdump-label.test b/test/Object/X86/objdump-label.test
new file mode 100644
index 00000000000..f8b933451e5
--- /dev/null
+++ b/test/Object/X86/objdump-label.test
@@ -0,0 +1,10 @@
+RUN: llvm-objdump -d %p/../Inputs/trivial-label-test.elf-x86-64 \
+RUN:              | FileCheck %s -check-prefix ELF-x86-64
+
+ELF-x86-64: file format ELF64-x86-64
+ELF-x86-64: Disassembly of section .text:
+ELF-x86-64: foo:
+ELF-x86-64:        0:	90                                           	nop
+ELF-x86-64: bum:
+ELF-x86-64:        1:	90                                           	nop
+
diff --git a/tools/llvm-objdump/llvm-objdump.cpp b/tools/llvm-objdump/llvm-objdump.cpp
index ebcee3b7f63..d7c9df1d6e7 100644
--- a/tools/llvm-objdump/llvm-objdump.cpp
+++ b/tools/llvm-objdump/llvm-objdump.cpp
@@ -494,17 +494,12 @@ static void DisassembleObject(const ObjectFile *Obj, bool InlineRelocs) {
     std::vector<RelocationRef>::const_iterator rel_end = Rels.end();
     // Disassemble symbol by symbol.
     for (unsigned si = 0, se = Symbols.size(); si != se; ++si) {
+
       uint64_t Start = Symbols[si].first;
-      uint64_t End;
-      // The end is either the size of the section or the beginning of the next
-      // symbol.
-      if (si == se - 1)
-        End = SectSize;
-      // Make sure this symbol takes up space.
-      else if (Symbols[si + 1].first != Start)
-        End = Symbols[si + 1].first - 1;
-      else
-        // This symbol has the same address as the next symbol. Skip it.
+      // The end is either the section end or the beginning of the next symbol.
+      uint64_t End = (si == se - 1) ? SectSize : Symbols[si + 1].first;
+      // If this symbol has the same address as the next symbol, then skip it.
+      if (Start == End)
         continue;
 
       outs() << '\n' << Symbols[si].second << ":\n";
-- 
2.34.1