[ThinLTO] Fix assertions on lazy-loading of Metadata TBAA attachments
Summary:
The issue happens with:
%0 = ....., !tbaa !0
%1 = ....., !tbaa !1
With !0 that references !1.
In this case when loading !0 we generates a temporary for the
operand !1. We now flush it immediately and trigger the load of
!1 before moving on. If we don't we get the temporary when
attaching to %1. This is usually not an issue except that we
eagerly try to update TBAA MDNodes, which is obviously not possible
if we only have a temporary.
Differential Revision: https://reviews.llvm.org/D28423
llvm-svn: 291362
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index c609ff0..89edbbe 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1562,8 +1562,6 @@
SmallVector<uint64_t, 64> Record;
- PlaceholderQueue Placeholders;
-
while (true) {
BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
@@ -1572,7 +1570,6 @@
case BitstreamEntry::Error:
return error("Malformed block");
case BitstreamEntry::EndBlock:
- resolveForwardRefsAndPlaceholders(Placeholders);
return Error::success();
case BitstreamEntry::Record:
// The interesting case.
@@ -1608,10 +1605,13 @@
auto Idx = Record[i + 1];
if (Idx < (MDStringRef.size() + GlobalMetadataBitPosIndex.size()) &&
- !MetadataList.lookup(Idx))
+ !MetadataList.lookup(Idx)) {
// Load the attachment if it is in the lazy-loadable range and hasn't
// been loaded yet.
+ PlaceholderQueue Placeholders;
lazyLoadOneMetadata(Idx, Placeholders);
+ resolveForwardRefsAndPlaceholders(Placeholders);
+ }
Metadata *Node = MetadataList.getMetadataFwdRef(Idx);
if (isa<LocalAsMetadata>(Node))