Implement support for dependent libraries. The "source" module's dependent

libraries list is merged into the "destination" module's list. Also, if the
source module is one of the dependent libraries, it is removed from the
list.

llvm-svn: 16282

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/Linker.cpp b/llvm/lib/VMCore/Linker.cpp
index 9e6759313bb..f75729b5194 100644
--- a/llvm/lib/VMCore/Linker.cpp
+++ b/llvm/lib/VMCore/Linker.cpp
@@ -23,6 +23,7 @@
 #include "llvm/SymbolTable.h"
 #include "llvm/Instructions.h"
 #include "llvm/Assembly/Writer.h"
+#include "llvm/System/Path.h"
 #include <iostream>
 #include <sstream>
 using namespace llvm;
@@ -835,6 +836,9 @@ static bool LinkAppendingVars(Module *M,
 // shouldn't be relied on to be consistent.
 //
 bool llvm::LinkModules(Module *Dest, const Module *Src, std::string *ErrorMsg) {
+  assert(Dest != 0 && "Invalid Destination module");
+  assert(Src  != 0 && "Invalid Source Module");
+
   if (Dest->getEndianness() == Module::AnyEndianness)
     Dest->setEndianness(Src->getEndianness());
   if (Dest->getPointerSize() == Module::AnyPointerSize)
@@ -847,6 +851,16 @@ bool llvm::LinkModules(Module *Dest, const Module *Src, std::string *ErrorMsg) {
       Dest->getPointerSize() != Src->getPointerSize())
     std::cerr << "WARNING: Linking two modules of different pointer size!\n";
 
+  // Update the destination module's dependent libraries list with the libraries 
+  // from the source module. There's no opportunity for duplicates here as the
+  // Module ensures that duplicate insertions are discarded.
+  Module::lib_iterator SI = Src->lib_begin();
+  Module::lib_iterator SE = Src->lib_end();
+  while ( SI != SE ) {
+    Dest->addLibrary(*SI);
+    ++SI;
+  }
+
   // LinkTypes - Go through the symbol table of the Src module and see if any
   // types are named in the src module that are not named in the Dst module.
   // Make sure there are no type name conflicts.
@@ -915,6 +929,13 @@ bool llvm::LinkModules(Module *Dest, const Module *Src, std::string *ErrorMsg) {
   //
   if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true;
 
+  // If the source library's module id is in the dependent library list of the
+  // destination library, remove it since that module is now linked in.
+  sys::Path modId;
+  modId.set_file(Src->getModuleIdentifier());
+  if (!modId.is_empty())
+    Dest->removeLibrary(modId.get_basename());
+
   return false;
 }