From 0c82561c4c5aced6caaf3a1d56d7704d95e3eae8 Mon Sep 17 00:00:00 2001
From: George Rimar <grimar@accesssoftek.com>
Date: Tue, 4 Oct 2016 08:49:52 +0000
Subject: [PATCH] [ELF] - Do not crash if common symbol has alignment 0.

Testcase contains a common symbol with zero alignment,
previously lld would crash, patch fixes that.

Differential revision: https://reviews.llvm.org/D25085

llvm-svn: 283197
---
 lld/ELF/InputFiles.cpp                                  |   3 +++
 lld/test/ELF/invalid/Inputs/common-symbol-alignment.elf | Bin 0 -> 456 bytes
 lld/test/ELF/invalid/common-symbol-alignment.s          |   6 ++++++
 3 files changed, 9 insertions(+)
 create mode 100644 lld/test/ELF/invalid/Inputs/common-symbol-alignment.elf
 create mode 100644 lld/test/ELF/invalid/common-symbol-alignment.s

diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 9d22956..0981e2c 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -400,6 +400,9 @@ SymbolBody *elf::ObjectFile<ELFT>::createSymbolBody(const Elf_Sym *Sym) {
                                               /*CanOmitFromDynSym*/ false, this)
         ->body();
   case SHN_COMMON:
+    if (Sym->st_value == 0)
+      fatal(getFilename(this) + ": common symbol '" + Name +
+            "' alignment is 0");
     return elf::Symtab<ELFT>::X->addCommon(Name, Sym->st_size, Sym->st_value,
                                            Binding, Sym->st_other,
                                            Sym->getType(), this)
diff --git a/lld/test/ELF/invalid/Inputs/common-symbol-alignment.elf b/lld/test/ELF/invalid/Inputs/common-symbol-alignment.elf
new file mode 100644
index 0000000000000000000000000000000000000000..9e7823b852b2c82881c6f44d75edc268eeafcbd8
GIT binary patch
literal 456
zcmb<-^>JfjWMqH=Mg}_u1P><4z;FV=WN-kp9T-@!s)Q(H2U0=|pZ-I52vQy_&V&$v
zvbce?00X8tgI-B$MF~SvVi7}CY6^p1aY<20ViJ(9%mvXvaU%?~$PwTNYGTHsaRF3J
t1x*e;j6i%4W<yiwfX0V$Szrt(Ee@oy_#PV83=9cSbufE4pnM4^4FF6u5{>`>

literal 0
HcmV?d00001

diff --git a/lld/test/ELF/invalid/common-symbol-alignment.s b/lld/test/ELF/invalid/common-symbol-alignment.s
new file mode 100644
index 0000000..671205f
--- /dev/null
+++ b/lld/test/ELF/invalid/common-symbol-alignment.s
@@ -0,0 +1,6 @@
+# REQUIRES: x86
+
+## common-symbol-alignment.elf contains common symbol with zero alignment.
+# RUN: not ld.lld %S/Inputs/common-symbol-alignment.elf \
+# RUN:   -o %t 2>&1 | FileCheck %s
+# CHECK: common symbol 'bar' alignment is 0
-- 
2.7.4