From 61de142984aa6cb1acfe4725183193d04e437420 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Fri, 5 Jul 2013 13:03:07 +0000
Subject: [PATCH] Don't create an archive if, for example, we are asked to
 print the index.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185697 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Object/ar-create.test | 17 +++++++++++++++++
 tools/llvm-ar/llvm-ar.cpp  | 21 +++++++++++++++++++--
 2 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 test/Object/ar-create.test

diff --git a/test/Object/ar-create.test b/test/Object/ar-create.test
new file mode 100644
index 00000000000..40e391da029
--- /dev/null
+++ b/test/Object/ar-create.test
@@ -0,0 +1,17 @@
+Test which operations create an archive and which don't.
+
+RUN: touch %t
+RUN: rm -f %t.foo.a
+RUN: not llvm-ar p %t.foo.a %t 2>&1 | FileCheck %s
+RUN: not llvm-ar d %t.foo.a %t 2>&1 | FileCheck %s
+RUN: not llvm-ar m %t.foo.a %t 2>&1 | FileCheck %s
+RUN: not llvm-ar t %t.foo.a %t 2>&1 | FileCheck %s
+RUN: not llvm-ar x %t.foo.a %t 2>&1 | FileCheck %s
+
+RUN: llvm-ar q %t.foo.a %t 2>&1 | FileCheck --check-prefix=CREATE %s
+RUN: rm -f %t.foo.a
+RUN: llvm-ar r %t.foo.a %t 2>&1 | FileCheck --check-prefix=CREATE %s
+RUN: rm -f %t.foo.a
+
+CHECK: .foo.a': No such file or directory
+CREATE: creating {{.*}}.foo.a
diff --git a/tools/llvm-ar/llvm-ar.cpp b/tools/llvm-ar/llvm-ar.cpp
index 53707154910..515f8991e84 100644
--- a/tools/llvm-ar/llvm-ar.cpp
+++ b/tools/llvm-ar/llvm-ar.cpp
@@ -642,6 +642,21 @@ doReplaceOrInsert(std::string* ErrMsg) {
   return false;
 }
 
+bool shouldCreateArchive(ArchiveOperation Op) {
+  switch (Op) {
+  case Print:
+  case Delete:
+  case Move:
+  case DisplayTable:
+  case Extract:
+    return false;
+
+  case QuickAppend:
+  case ReplaceOrInsert:
+    return true;
+  }
+}
+
 // main - main program for llvm-ar .. see comments in the code
 int main(int argc, char **argv) {
   program_name = argv[0];
@@ -665,13 +680,15 @@ int main(int argc, char **argv) {
   ArchiveOperation Operation = parseCommandLine();
 
   // Create or open the archive object.
-  if (!llvm::sys::fs::exists(ArchiveName)) {
+  if (shouldCreateArchive(Operation) && !llvm::sys::fs::exists(ArchiveName)) {
     // Produce a warning if we should and we're creating the archive
     if (!Create)
       errs() << argv[0] << ": creating " << ArchiveName << "\n";
     TheArchive = Archive::CreateEmpty(ArchiveName, Context);
     TheArchive->writeToDisk();
-  } else {
+  }
+
+  if (!TheArchive) {
     std::string Error;
     TheArchive = Archive::OpenAndLoad(ArchiveName, Context, &Error);
     if (TheArchive == 0) {