IR, Bitcode: Change bitcode reader to no longer own its memory buffer.

Unique ownership is just one possible ownership pattern for the memory buffer
underlying the bitcode reader. In practice, as this patch shows, ownership can
often reside at a higher level. With the upcoming change to allow multiple
modules in a single bitcode file, it will no longer be appropriate for
modules to generally have unique ownership of their memory buffer.

The C API exposes the ownership relation via the LLVMGetBitcodeModuleInContext
and LLVMGetBitcodeModuleInContext2 functions, so we still need some way for
the module to own the memory buffer. This patch does so by adding an owned
memory buffer field to Module, and using it in a few other places where it
is convenient.

Differential Revision: https://reviews.llvm.org/D26384

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286214 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 2 deletions

diff --git a/lib/LTO/LTOBackend.cpp b/lib/LTO/LTOBackend.cpp
index b00c37f7254..0885c0b8484 100644
--- a/lib/LTO/LTOBackend.cpp
+++ b/lib/LTO/LTOBackend.cpp
@@ -352,8 +352,7 @@ Error lto::thinBackend(Config &Conf, unsigned Task, AddStreamFn AddStream,
   auto ModuleLoader = [&](StringRef Identifier) {
     assert(Mod.getContext().isODRUniquingDebugTypes() &&
            "ODR Type uniquing should be enabled on the context");
-    return std::move(getLazyBitcodeModule(MemoryBuffer::getMemBuffer(
-                                              ModuleMap[Identifier], false),
+    return std::move(getLazyBitcodeModule(ModuleMap[Identifier],
                                           Mod.getContext(),
                                           /*ShouldLazyLoadMetadata=*/true)
                          .get());