[llvm] r263143 - Materialize metadata in IRLinker before value mapping

[Teresa Johnson via llvm-commits]

Author: tejohnson
Date: Thu Mar 10 12:47:03 2016
New Revision: 263143

URL: http://llvm.org/viewvc/llvm-project?rev=263143&view=rev
Log:
Materialize metadata in IRLinker before value mapping

Summary:
Unless we plan to do later postpass metadata linking (ThinLTO special mode),
always invoke metadata materialization at the start of IRLinker::run().
This avoids the need for clients who use lazy metadata loading to
explicitly invoke materializeMetadata before the IRMover, which in
turn invokes IRLinker::run and needs materialized metadata for mapping.

Came up in the context of an LLD issue (D17982).

Reviewers: rafael

Subscribers: silvas, llvm-commits

Differential Revision: http://reviews.llvm.org/D17992

Modified:
    llvm/trunk/lib/Linker/IRMover.cpp

Modified: llvm/trunk/lib/Linker/IRMover.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Linker/IRMover.cpp?rev=263143&r1=263142&r2=263143&view=diff
==============================================================================
--- llvm/trunk/lib/Linker/IRMover.cpp (original)
+++ llvm/trunk/lib/Linker/IRMover.cpp Thu Mar 10 12:47:03 2016
@@ -1492,6 +1492,11 @@ static std::string mergeTriples(const Tr
 }
 
 bool IRLinker::run() {
+  // Ensure metadata materialized before value mapping.
+  if (shouldLinkMetadata() && SrcM->getMaterializer())
+    if (SrcM->getMaterializer()->materializeMetadata())
+      return true;
+
   // Inherit the target data from the source module if the destination module
   // doesn't have one already.
   if (DstM.getDataLayout().isDefault())
@@ -1559,13 +1564,9 @@ bool IRLinker::run() {
     // Even if just linking metadata we should link decls above in case
     // any are referenced by metadata. IRLinker::shouldLink ensures that
     // we don't actually link anything from source.
-    if (IsMetadataLinkingPostpass) {
-      // Ensure metadata materialized
-      if (SrcM->getMaterializer()->materializeMetadata())
-        return true;
+    if (IsMetadataLinkingPostpass)
       SrcM->getMaterializer()->saveMetadataList(MetadataToIDs,
                                                 /* OnlyTempMD = */ false);
-    }
 
     linkNamedMDNodes();