Only computeRelativePath() on new members

[marksantaniello]

Summary

When using thin archives, and processing the same archive multiple times, we were mangling existing entries. The root cause is that we were calling computeRelativePath() more than once. Here, we only call it when adding new members to an archive.

Note that D27218 changes the way thin archives are printed, and will break the new unit test included here. Depending on which one lands first, the other will need to be slightly modified.

[davide]

LGTM. Do you need somebody to commit this on your behalf?

[marksantaniello]

Remove trailing whitespace

[marksantaniello]

Previous diff was a mistake. Got the revisions mixed up. Here I add the final newline to the new test.

[marksantaniello]

Thanks @davide, looks like I'm all set since @david2050 already did it.

test/Object/archive-toc.test

+RUN: cd %p
+
 Test reading an archive created by gnu ar
-RUN: env TZ=GMT llvm-ar tv %p/Inputs/GNU.a | FileCheck %s --check-prefix=GNU -strict-whitespace
+RUN: env TZ=GMT llvm-ar tv Inputs/GNU.a | FileCheck %s --check-prefix=GNU -strict-whitespace
 
 GNU:      rw-r--r-- 500/500      8 2004-11-19 02:57:37.000000000 evenlen
 GNU-NEXT: rw-r--r-- 500/500      7 2004-11-19 02:57:21.000000000 oddlen
 GNU-NEXT: rwxr-xr-x 500/500   1465 2004-11-19 03:01:31.000000000 very_long_bytecode_file_name.bc
 GNU-NEXT: rw-r--r-- 500/500   2280 2004-11-19 03:04:30.000000000 IsNAN.o
 
 
 Test reading an archive createdy by Mac OS X ar
-RUN: env TZ=GMT llvm-ar tv %p/Inputs/MacOSX.a | FileCheck %s --check-prefix=OSX -strict-whitespace
+RUN: env TZ=GMT llvm-ar tv Inputs/MacOSX.a | FileCheck %s --check-prefix=OSX -strict-whitespace
 
 OSX-NOT: __.SYMDEF
 OSX:      rw-r--r-- 501/501      8 2004-11-19 02:57:37.000000000 evenlen
 OSX-NEXT: rw-r--r-- 501/501      8 2004-11-19 02:57:21.000000000 oddlen
 OSX-NEXT: rw-r--r-- 502/502   1465 2010-02-04 06:59:14.000000000 very_long_bytecode_file_name.bc
 OSX-NEXT: rw-r--r-- 501/501   2280 2004-11-19 04:32:06.000000000 IsNAN.o
 
 Test reading an archive created on Solaris by /usr/ccs/bin/ar
-RUN: env TZ=GMT llvm-ar tv %p/Inputs/SVR4.a | FileCheck %s -strict-whitespace
+RUN: env TZ=GMT llvm-ar tv Inputs/SVR4.a | FileCheck %s -strict-whitespace
 
 Test reading an archive created on Solaris by /usr/xpg4/bin/ar
-RUN: env TZ=GMT llvm-ar tv %p/Inputs/xpg4.a | FileCheck %s -strict-whitespace
+RUN: env TZ=GMT llvm-ar tv Inputs/xpg4.a | FileCheck %s -strict-whitespace
 
 CHECK:      rw-r--r-- 1002/102      8 2004-11-19 03:24:02.000000000 evenlen
 CHECK-NEXT: rw-r--r-- 1002/102      7 2004-11-19 03:24:02.000000000 oddlen
 CHECK-NEXT: rwxr-xr-x 1002/102   1465 2004-11-19 03:24:02.000000000 very_long_bytecode_file_name.bc
 CHECK-NEXT: rw-r--r-- 1002/102   2280 2004-11-19 03:24:02.000000000 IsNAN.o
 
 Test reading a thin archive created by gnu ar
-RUN: env TZ=GMT llvm-ar tv %p/Inputs/thin.a | FileCheck %s --check-prefix=THIN -strict-whitespace
+RUN: env TZ=GMT llvm-ar tv Inputs/thin.a | FileCheck %s --check-prefix=THIN -strict-whitespace
 
-THIN:      rw-r--r-- 1000/1000      8 2014-12-16 00:56:27.000000000 evenlen
-THIN-NEXT: rw-r--r-- 1000/1000      7 2014-12-16 00:56:27.000000000 oddlen
-THIN-NEXT: rwxr-xr-x 1000/1000   1465 2014-12-16 00:56:27.000000000 very_long_bytecode_file_name.bc
-THIN-NEXT: rw-r--r-- 1000/1000   2280 2014-12-16 00:56:27.000000000 IsNAN.o
+THIN:      rw-r--r-- 1000/1000      8 2014-12-16 00:56:27.000000000 Inputs/evenlen
+THIN-NEXT: rw-r--r-- 1000/1000      7 2014-12-16 00:56:27.000000000 Inputs/oddlen
+THIN-NEXT: rwxr-xr-x 1000/1000   1465 2014-12-16 00:56:27.000000000 Inputs/very_long_bytecode_file_name.bc
+THIN-NEXT: rw-r--r-- 1000/1000   2280 2014-12-16 00:56:27.000000000 Inputs/IsNAN.o
 
 Test reading an archive with just a symbol table. We use to reject them.
-RUN: llvm-ar tv %p/Inputs/symtab-only.a | FileCheck --allow-empty --check-prefix=EMPTY %s
+RUN: llvm-ar tv Inputs/symtab-only.a | FileCheck --allow-empty --check-prefix=EMPTY %s
 EMPTY-NOT: {{.}}
 
 Test reading a thin archive with directory names.
-RUN: env TZ=GMT llvm-ar tv %p/Inputs/thin-path.a | FileCheck %s --check-prefix=THINPATH -strict-whitespace
+RUN: env TZ=GMT llvm-ar tv Inputs/thin-path.a | FileCheck %s --check-prefix=THINPATH -strict-whitespace
 
-THINPATH: rw-r--r-- 0/0   1224 1970-01-01 00:00:00.000000000 test.o
-THINPATH-NEXT: rw-r--r-- 0/0   1224 1970-01-01 00:00:00.000000000 t/test2.o
+THINPATH: rw-r--r-- 0/0   1224 1970-01-01 00:00:00.000000000 Inputs/test.o
+THINPATH-NEXT: rw-r--r-- 0/0   1224 1970-01-01 00:00:00.000000000 Inputs/t/test2.o

tools/llvm-ar/llvm-ar.cpp

if (Verbose) {
     Expected<uint64_t> Size = C.getSize();
     failIfError(Size.takeError());
     outs() << ' ' << format("%6llu", Size.get());
     auto ModTimeOrErr = C.getLastModified();
     failIfError(ModTimeOrErr.takeError());
     outs() << ' ' << ModTimeOrErr.get();
     outs() << ' ';
   }
+
+  if (C.getParent()->isThin()) {
+    outs() << sys::path::parent_path(ArchiveName);
+    outs() << sys::path::get_separator();
+  }
   outs() << Name << "\n";
 }
 
 // Implement the 'x' operation. This function extracts files back to the file
 // system.
 static void doExtract(StringRef Name, const object::Archive::Child &C) {
   // Retain the original mode.
   Expected<sys::fs::perms> ModeOrErr = C.getAccessMode();