[Bitcode] Address backwards compat bug in r342631
r342631 expanded bitc::METADATA_LOCATION by one element. The bitcode
metadata loader was changed in a backwards-incompatible way, leading to
crashes when disassembling old bitcode:
assertion: empty() && "PlaceholderQueue hasn't been flushed before being destroyed"
Assertion failed: (empty() && "PlaceholderQueue hasn't been flushed before being destroyed")
This commit teaches the metadata loader to assume that the newly-added
IsImplicitCode bit is 'false' when not present in old bitcode. I've added a
bitcode compat regression test.
rdar://44645820
llvm-svn: 342678
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index 1af17f4..3fe7d22 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1139,7 +1139,7 @@
break;
}
case bitc::METADATA_LOCATION: {
- if (Record.size() != 6)
+ if (Record.size() != 5 && Record.size() != 6)
return error("Invalid record");
IsDistinct = Record[0];
@@ -1147,7 +1147,7 @@
unsigned Column = Record[2];
Metadata *Scope = getMD(Record[3]);
Metadata *InlinedAt = getMDOrNull(Record[4]);
- bool ImplicitCode = Record[5];
+ bool ImplicitCode = Record.size() == 6 && Record[5];
MetadataList.assignValue(
GET_OR_DISTINCT(DILocation, (Context, Line, Column, Scope, InlinedAt,
ImplicitCode)),