[lld] r298034 - COFF: Do not create empty temporary archives for /msvclto.

[Peter Collingbourne via llvm-commits]

Author: pcc
Date: Thu Mar 16 21:04:22 2017
New Revision: 298034

URL: http://llvm.org/viewvc/llvm-project?rev=298034&view=rev
Log:
COFF: Do not create empty temporary archives for /msvclto.

The MSVC linker doesn't support them.

Differential Revision: https://reviews.llvm.org/D31067

Modified:
    lld/trunk/COFF/Driver.cpp
    lld/trunk/test/COFF/msvclto-archive.ll

Modified: lld/trunk/COFF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Driver.cpp?rev=298034&r1=298033&r2=298034&view=diff
==============================================================================
--- lld/trunk/COFF/Driver.cpp (original)
+++ lld/trunk/COFF/Driver.cpp Thu Mar 16 21:04:22 2017
@@ -475,9 +475,6 @@ filterBitcodeFiles(StringRef Path, std::
   if (!needsRebuilding(MBRef))
     return Path.str();
 
-  log("Creating a temporary archive for " + Path +
-      " to remove bitcode files");
-
   std::unique_ptr<Archive> File =
       check(Archive::create(MBRef),
             MBRef.getBufferIdentifier() + ": failed to parse archive");
@@ -487,6 +484,11 @@ filterBitcodeFiles(StringRef Path, std::
     if (identify_magic(Member.getBuffer()) != file_magic::bitcode)
       New.emplace_back(Member);
 
+  if (New.empty())
+    return None;
+
+  log("Creating a temporary archive for " + Path + " to remove bitcode files");
+
   SmallString<128> S;
   if (auto EC = sys::fs::createTemporaryFile("lld-" + sys::path::stem(Path),
                                              ".lib", S))

Modified: lld/trunk/test/COFF/msvclto-archive.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/msvclto-archive.ll?rev=298034&r1=298033&r2=298034&view=diff
==============================================================================
--- lld/trunk/test/COFF/msvclto-archive.ll (original)
+++ lld/trunk/test/COFF/msvclto-archive.ll Thu Mar 16 21:04:22 2017
@@ -1,5 +1,7 @@
 ;; Make sure we re-create archive files to strip bitcode files.
 
+;; Do not create empty archives because the MSVC linker
+;; doesn't support them.
 ; RUN: llvm-as -o %t.obj %s
 ; RUN: rm -f %t-main1.a
 ; RUN: llvm-ar cru %t-main1.a %t.obj
@@ -8,7 +10,7 @@
 ; RUN: lld-link %t-main1.a %t.dir/bitcode.obj /msvclto /out:%t.exe /opt:lldlto=1 /opt:icf \
 ; RUN:   /entry:main /verbose > %t.log || true
 ; RUN: FileCheck -check-prefix=BC %s < %t.log
-; BC: Creating a temporary archive for
+; BC-NOT: Creating a temporary archive for
 
 ; RUN: rm -f %t-main2.a
 ; RUN: llvm-ar cru %t-main2.a %t.dir/bitcode.obj