From b50f7b927b2ae99543c747a480b03969f0e73c87 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Fri, 16 Dec 2016 16:31:10 +0000
Subject: [PATCH] dwarfdump: Support/process relocations on a CU's abbrev_off

Input can be produced by ld -r, for example (a normal LLVM workflow
never hits this - LLVM only ever produces a single abbrev table in an
object (shared by multiple CUs), so the reloc's always 0, and when it's
linked together the relocation's resolved so it doesn't need to be
handled)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289954 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/DebugInfo/DWARF/DWARFUnit.cpp                     |   3 +++
 test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64 | Bin 0 -> 2720 bytes
 test/DebugInfo/dwarfdump-abbrev-off.test              |   8 ++++++++
 3 files changed, 11 insertions(+)
 create mode 100644 test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64
 create mode 100644 test/DebugInfo/dwarfdump-abbrev-off.test

diff --git a/lib/DebugInfo/DWARF/DWARFUnit.cpp b/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 2ddbc507ff6..8e5691aebab 100644
--- a/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -87,7 +87,10 @@ bool DWARFUnit::getStringOffsetSectionItem(uint32_t Index,
 bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
   Length = debug_info.getU32(offset_ptr);
   Version = debug_info.getU16(offset_ptr);
+  auto AI = InfoSection.Relocs.find(*offset_ptr);
   uint64_t AbbrOffset = debug_info.getU32(offset_ptr);
+  if (AI != InfoSection.Relocs.end())
+    AbbrOffset += AI->second.second;
   if (IndexEntry) {
     if (AbbrOffset)
       return false;
diff --git a/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64 b/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64
new file mode 100644
index 0000000000000000000000000000000000000000..bc196b5995bc5ef9534950e10f6dc290ab882fb8
GIT binary patch
literal 2720
zcmb_e&1(};5T8x@Wj|s+{HRtXph6Ygt+8P1S5wqlv4{v&QKW9tZ5z7Tgxxf>MNkon
z9t831LGhqhkKPn7{s{%Wde^fDo!OmfUS2mA#7Fkc%x~uRX5PoX&4Y_m6A8lrX$G8w
znk6W}tLB=X4b?2{fIgU>eER+FXFxq_#_Dx2mb;CC&epc)IM6<X>7mv_-FT{dEpfgp
z)X~hlwl|-yI(|?ndFf$u$Q()!R{SMzF`XG19T^=uk{)#3YSB`#<43?Y^W`#FOM!2>
zrM&H0^QF?f>sSk=qGRP;yRcYrtXZdO1$p1D<QJ@<u<Fd%p6#v#g#dCPedcy%E>nfM
z3>ZCdIMvsjOm*)bNMTh*k5RLGj9#oZVFD@HelL|wo$5H<F}4Q-_u|up4?tVEYLOlS
z*k$o)?3E~5iiBzyH^hoI<{#IH>Pz4j;dG2&sV?lp;jm8poeZ6{Gn<{!>Yxi?+eTqV
zv(bJfk-+fKA^X>kRx(7Qu9J1bH@K+xYB=Smwkr}q@yZbk7nWQy&RLE-#8UEhvwc*-
z)x1L*US)e&!71;4wnr44#*w^d7^m4sD-Z#f8{jt?m-_FseMiF|v%M2#RQCncXf}8(
zm8PyY9jOECOS2@dTGs^Qdc6$Cie%jgwUA`p4y(AjV=6Ay)-ckN;cnJrR9_SP{9TU%
zv^K!I5bss$+{hH&2z4(un6pl9X@17e<$R|KX2n^qfSE59i;jni@3=Ncl$UazU33Cr
z_;@MRtf1nHqiE*~-dw4U906Xb;+U7NP9F;@c7Cxgz%6(V1J1(CoR67gJiNTX3>Gj$
z#m=E7a-~T2e`wor3|ixjb>cCzEOlJoCw9XNRFGee&ZeLMldQ`7BAzx;SdOEl{PG@(
z`ynf90<ff5Y9e1Mdg$P;MFLbXCYHkDLWMuN1^-?H{umFcZ<3ztL<9b7J&^0r;i)b7
z`o8FVx>pF(*Z&O%>iZ{rk&hbW|H=Wk(62V(2}buF-B(!wSdMVv*O<_QIGsf~Km8nc
z5T!mQxt{Pxhdy#@(_`tLjLZLy`I3k7)3-~{|EvN3V+^0Br1R<CkITOv!>4bB&UX>h
z=Y$aaU_R-8Yah_5pAm`|{yLNC`%Jm@{O=KqOZ9~&g-!nVMb_q8-=ZUq|Bd;dgve5#
F>mR?$y{Z5J

literal 0
HcmV?d00001

diff --git a/test/DebugInfo/dwarfdump-abbrev-off.test b/test/DebugInfo/dwarfdump-abbrev-off.test
new file mode 100644
index 00000000000..2937d8cbdde
--- /dev/null
+++ b/test/DebugInfo/dwarfdump-abbrev-off.test
@@ -0,0 +1,8 @@
+RUN: llvm-dwarfdump -debug-dump=info %p/Inputs/dwarfdump-abbrev-off.elf-x86-64 | FileCheck %s
+
+Check that we apply relocations to the abbr_offset - while LLVM never produces
+an object file like this, a reproduction can be produced by linking two simple
+object files together with ld -r.
+
+CHECK: abbr_offset = 0x0000
+CHECK: abbr_offset = 0x0010
-- 
2.11.0