From cbe392629b55999f2bd37e10048b0e00630a9d0d Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@google.com>
Date: Tue, 2 Feb 2016 22:48:04 +0000
Subject: [PATCH] ELF: Do not exit if it cannot open an output file.

It can fail to open an output file for various reasons, including
lack of permission, too long filename, or the output file is not
a mmap'able file.

llvm-svn: 259596
---
 lld/ELF/Writer.cpp       | 14 +++++++++-----
 lld/test/ELF/driver.test | 11 +++++++++++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 3a317b3..1e94b03 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -56,7 +56,7 @@ private:
   void assignAddresses();
   void buildSectionMap();
   void fixAbsoluteSymbols();
-  void openFile(StringRef OutputPath);
+  bool openFile();
   void writeHeader();
   void writeSections();
   bool isDiscarded(InputSectionBase<ELFT> *IS) const;
@@ -172,7 +172,8 @@ template <class ELFT> void Writer<ELFT>::run() {
     return;
   assignAddresses();
   fixAbsoluteSymbols();
-  openFile(Config->OutputFile);
+  if (!openFile())
+    return;
   writeHeader();
   writeSections();
   if (HasError)
@@ -1384,11 +1385,14 @@ template <class ELFT> void Writer<ELFT>::writeHeader() {
     Sec->writeHeaderTo(++SHdrs);
 }
 
-template <class ELFT> void Writer<ELFT>::openFile(StringRef Path) {
+template <class ELFT> bool Writer<ELFT>::openFile() {
   ErrorOr<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
-      FileOutputBuffer::create(Path, FileSize, FileOutputBuffer::F_executable);
-  fatal(BufferOrErr, "failed to open " + Path);
+      FileOutputBuffer::create(Config->OutputFile, FileSize,
+                               FileOutputBuffer::F_executable);
+  if (error(BufferOrErr, "failed to open " + Config->OutputFile))
+    return false;
   Buffer = std::move(*BufferOrErr);
+  return true;
 }
 
 // Write section contents to a mmap'ed file.
diff --git a/lld/test/ELF/driver.test b/lld/test/ELF/driver.test
index 13f040e..70fe7ba 100644
--- a/lld/test/ELF/driver.test
+++ b/lld/test/ELF/driver.test
@@ -1,3 +1,5 @@
+# REQUIRES: x86
+
 # RUN: not ld.lld -unknown1 -unknown2 -m foo /no/such/file -lnosuchlib \
 # RUN:   2>&1 | FileCheck %s
 
@@ -7,3 +9,12 @@
 # CHECK: Unknown emulation: foo
 # CHECK: cannot open /no/such/file
 # CHECK: Unable to find library -lnosuchlib
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: not ld.lld %t -o /dev/null 2>&1 | FileCheck -check-prefix=CHECK2 %s
+
+# CHECK2: failed to open
+
+.globl _start
+_start:
+  nop
-- 
2.7.4