From a49b05bb61f73eee3ebfa6c985c1d19356d383b5 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames@gmail.com>
Date: Sat, 15 Aug 2020 15:45:49 -0700
Subject: [PATCH] [JITLink][MachO] Use correct symbol scope when N_PEXT is set
 and N_EXT unset.

MachOLinkGraphBuilder has been treating these as hidden, but they should be
treated as local.

Symbols with N_PEXT set and N_EXT unset are produced when hidden symbols are
run through 'ld -r' without passing -keep_private_externs. They will show up
under 'nm -m' as "was private extern", hence the name of the test cases.

Testcase commited as relocatable object to ensure that the test suite doesn't
depend on having 'ld -r' available.
---
 .../lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp |   4 +---
 .../JITLink/X86/Inputs/MachO_x86-64_was_private_extern.o  | Bin 0 -> 480 bytes
 .../JITLink/X86/MachO_x86-64_was_private_extern.test      |   9 +++++++++
 3 files changed, 10 insertions(+), 3 deletions(-)
 create mode 100644 llvm/test/ExecutionEngine/JITLink/X86/Inputs/MachO_x86-64_was_private_extern.o
 create mode 100644 llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_was_private_extern.test

diff --git a/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp b/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp
index fa3f403..cf1bb23 100644
--- a/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp
+++ b/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp
@@ -64,10 +64,8 @@ Linkage MachOLinkGraphBuilder::getLinkage(uint16_t Desc) {
 }
 
 Scope MachOLinkGraphBuilder::getScope(StringRef Name, uint8_t Type) {
-  if (Type & MachO::N_PEXT)
-    return Scope::Hidden;
   if (Type & MachO::N_EXT) {
-    if (Name.startswith("l"))
+    if ((Type & MachO::N_PEXT) || Name.startswith("l"))
       return Scope::Hidden;
     else
       return Scope::Default;
diff --git a/llvm/test/ExecutionEngine/JITLink/X86/Inputs/MachO_x86-64_was_private_extern.o b/llvm/test/ExecutionEngine/JITLink/X86/Inputs/MachO_x86-64_was_private_extern.o
new file mode 100644
index 0000000000000000000000000000000000000000..c1357461b9dd2d67a130dd3acf934b0dc444bf56
GIT binary patch
literal 480
zcmX^A>+L^w1_nlE1|R{%EI@1kVkiJH5J&>?3or{iAr2KT0O<h&7$0aR0|+yL1c4wv
zz9hAx1j2^!LtG<55PTR*7|H;d2XadXkOmvg!q5Oy1ES;OlZ#7=GV{`*g7NXF=E2MX
znE?XLQ1?N22zMd#C4ig>Ky{$7H~^#-fV2@1gJ>X^fq|b3j6rOW8U{8UCQTqE0K_1D
z!~l<8R*<s8{PHbe<%S0ir{(8E&0}DY1%;m+FwkJ`2ZbL$lG%b#KFCfGP+*8p%uCM5
UFN%i-M|^H#W*&o&vmrzt011F2_y7O^

literal 0
HcmV?d00001

diff --git a/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_was_private_extern.test b/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_was_private_extern.test
new file mode 100644
index 0000000..75e3847
--- /dev/null
+++ b/llvm/test/ExecutionEngine/JITLink/X86/MachO_x86-64_was_private_extern.test
@@ -0,0 +1,9 @@
+# RUN: llvm-jitlink -noexec %S/Inputs/MachO_x86-64_was_private_extern.o
+#
+# Perform a no-exec link of MachO_x86-64_was_private_extern.o and verify that
+# it does not generate any errors despite the presence of a 'was private
+# extern' symbol (N_PEXT set, N_EXT unset).
+#
+# The test case for this is a relocatable object file rather than assembly as
+# objects must be run through ld64's 'ld -r' mode to produce them and we can't
+# assume that that is available everywhere.
-- 
2.7.4