[llvm-ar] Support multiple dashed options

This allows syntax like:
$ llvm-ar -c -r -u file.a file.o

This is in addition to the other formats that are already supported:
$ llvm-ar cru file.a file.o
$ llvm-ar -cru file.a file.o

Patch by Tom Anderson!

Differential Revision: https://reviews.llvm.org/D44452

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328716 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Object/ArchiveWriter.cpp

@@ -35,15 +35,6 @@
 
 using namespace llvm;
 
-// The SYM64 format is used when an archive's member offsets are larger than
-// 32-bits can hold. The need for this shift in format is detected by
-// writeArchive. To test this we need to generate a file with a member that has
-// an offset larger than 32-bits but this demands a very slow test. To speed
-// the test up we use this flag to pretend like the cutoff happens before
-// 32-bits and instead happens at some much smaller value.
-static cl::opt<int> Sym64Threshold("sym64-threshold", cl::Hidden,
-                                   cl::init(32));
-
 NewArchiveMember::NewArchiveMember(MemoryBufferRef BufRef)
     : Buf(MemoryBuffer::getMemBuffer(BufRef, false)),
       MemberName(BufRef.getBufferIdentifier()) {}
@@ -490,6 +481,19 @@ Error llvm::writeArchive(StringRef ArcName,
       // We assume 32-bit symbols to see if 32-bit symbols are possible or not.
       MaxOffset += M.Symbols.size() * 4;
     }
+
+    // The SYM64 format is used when an archive's member offsets are larger than
+    // 32-bits can hold. The need for this shift in format is detected by
+    // writeArchive. To test this we need to generate a file with a member that
+    // has an offset larger than 32-bits but this demands a very slow test. To
+    // speed the test up we use this environment variable to pretend like the
+    // cutoff happens before 32-bits and instead happens at some much smaller
+    // value.
+    const char *Sym64Env = std::getenv("SYM64_THRESHOLD");
+    int Sym64Threshold = 32;
+    if (Sym64Env)
+      StringRef(Sym64Env).getAsInteger(10, Sym64Threshold);
+
     // If LastOffset isn't going to fit in a 32-bit varible we need to switch
     // to 64-bit. Note that the file can be larger than 4GB as long as the last
     // member starts before the 4GB offset.

test/Object/archive-GNU64-write.test

@@ -5,7 +5,7 @@
 # RUN: dd if=%t of=%t bs=1 count=0 seek=1M
 # RUN: rm -f %t.lib
 # RUN: cp %t %t2
-# RUN: llvm-ar -sym64-threshold=19 cr %t.lib %t %t2 %p/Inputs/trivial-object-test.elf-x86-64
+# RUN: SYM64_THRESHOLD=19 llvm-ar cr %t.lib %t %t2 %p/Inputs/trivial-object-test.elf-x86-64
 # RUN: llvm-nm --print-armap %t.lib | FileCheck %s
 # RUN: grep SYM64 %t.lib
 

test/tools/llvm-ar/default-add.test

@@ -14,5 +14,21 @@ RUN: not grep -q __.SYMDEF %t.ar
 RUN: llvm-ar crs %t.ar %t-macho.o
 RUN: not grep -q __.SYMDEF %t.ar
 
+RUN: rm -f %t.ar
+Test that multiple dashed options works.
+RUN: llvm-ar -c -r -s %t.ar %t-macho.o
+RUN: grep -q __.SYMDEF %t.ar
+Test with duplicated options.
+RUN: llvm-ar -c -r -s -c -s %t.ar %t-coff.o
+RUN: grep -q __.SYMDEF %t.ar
+
+RUN: rm -f %t.ar
+Test with the options in a different order.
+RUN: llvm-ar rsc %t.ar %t-macho.o
+RUN: grep -q __.SYMDEF %t.ar
+Test with options everywhere.
+RUN: llvm-ar rsc -cs -sc %t.ar %t-coff.o -cs -sc
+RUN: grep -q __.SYMDEF %t.ar
+
 Ensure that we select the existing format when updating.