[PATCH] Fix the --enable-shared build

[Sanjoy Das]

The shared-object build for llvm (i.e. libLLVM-3.5svn.so + tools)
currently breaks on linux when linking opt.  This patch is an attempt
to fix that.

-- Sanjoy
-------------- next part --------------
commit 080fb498017d17af2e4d7563608c7d8a848f20da
Author: Sanjoy Das <sanjoy at azulsystems.com>
Date:   Thu Jun 19 15:38:02 2014 -0700

    Fix the --enable-shared build.
    
    Currently a build configured with ./configure --enable-shared breaks
    with an undefined "llvm::cl::parser<llvm::PassInfo
    const*>::getOption(unsigned int) const" symbol when linking opt.  This
    body for this symbol gets emitted into Pass.o (along with the destructor
    for PassNameParser), but gets linked into libLLVM-3.5svn.so with local
    visibility, causing the link error.
    
    This fix uses the existing EXTERN_TEMPLATE machinery to force a globally
    visible definition for the functions in parser<const PassInfo *> into
    Pass.o.

diff --git a/include/llvm/IR/LegacyPassNameParser.h b/include/llvm/IR/LegacyPassNameParser.h
index e2e4912..a07e3fd 100644
--- a/include/llvm/IR/LegacyPassNameParser.h
+++ b/include/llvm/IR/LegacyPassNameParser.h
@@ -95,6 +95,8 @@ private:
   }
 };
 
+EXTERN_TEMPLATE_INSTANTIATION(class cl::parser<const PassInfo *>);
+
 ///===----------------------------------------------------------------------===//
 /// FilteredPassNameParser class - Make use of the pass registration
 /// mechanism to automatically add a command line argument to opt for
diff --git a/lib/IR/Pass.cpp b/lib/IR/Pass.cpp
index 91d86ae..00ce223 100644
--- a/lib/IR/Pass.cpp
+++ b/lib/IR/Pass.cpp
@@ -234,6 +234,8 @@ PassNameParser::~PassNameParser() {
   // attempting to remove the registration listener is an error.
 }
 
+TEMPLATE_INSTANTIATION(class cl::parser<const PassInfo *>);
+
 //===----------------------------------------------------------------------===//
 //   AnalysisUsage Class Implementation
 //