Add support for the 's' operation to llvm-ar.

If no other operation is specified, 's' becomes an operation instead of an
modifier. The s operation just creates a symbol table. It is the same as
running ranlib.

We assume the archive was created by a sane ar (like llvm-ar or gnu ar) and
if the symbol table is present, then it is current. We use that to optimize
the most common case: a broken build system that thinks it has to run ranlib.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187353 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/Object/Archive.cpp b/lib/Object/Archive.cpp
index c6cf219..71efca2 100644
--- a/lib/Object/Archive.cpp
+++ b/lib/Object/Archive.cpp
@@ -385,7 +385,7 @@ Archive::Symbol Archive::Symbol::getNext() const {
 }
 
 Archive::symbol_iterator Archive::begin_symbols() const {
-  if (SymbolTable == end_children())
+  if (!hasSymbolTable())
     return symbol_iterator(Symbol(this, 0, 0));
 
   const char *buf = SymbolTable->getBuffer().begin();
@@ -408,7 +408,7 @@ Archive::symbol_iterator Archive::begin_symbols() const {
 }
 
 Archive::symbol_iterator Archive::end_symbols() const {
-  if (SymbolTable == end_children())
+  if (!hasSymbolTable())
     return symbol_iterator(Symbol(this, 0, 0));
 
   const char *buf = SymbolTable->getBuffer().begin();
@@ -444,3 +444,7 @@ Archive::child_iterator Archive::findSym(StringRef name) const {
   }
   return end_children();
 }
+
+bool Archive::hasSymbolTable() const {
+  return SymbolTable != end_children();
+}