From 13d5c58951083fd44481974a2beb764914f20907 Mon Sep 17 00:00:00 2001
From: "Duncan P. N. Exon Smith" <dexonsmith@apple.com>
Date: Wed, 6 Apr 2016 02:06:40 +0000
Subject: [PATCH] AsmParser: Don't crash on unresolved !tbaa

Instead of crashing, give a nice error.  As a drive-by, fix the location
associated with the errors for unresolved metadata (the location was off
by one token).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265507 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/AsmParser/LLParser.cpp              |  9 +++++----
 test/Assembler/invalid-mdnode-badref.ll |  2 +-
 test/Assembler/missing-tbaa.ll          | 11 +++++++++++
 3 files changed, 17 insertions(+), 5 deletions(-)
 create mode 100644 test/Assembler/missing-tbaa.ll

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 3eb52ea2282..369dbb38f7c 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -100,9 +100,6 @@ void LLParser::restoreParsingState(const SlotMapping *Slots) {
 /// ValidateEndOfModule - Do final validity and sanity checks at the end of the
 /// module.
 bool LLParser::ValidateEndOfModule() {
-  for (unsigned I = 0, E = InstsWithTBAATag.size(); I < E; I++)
-    UpgradeInstWithTBAATag(InstsWithTBAATag[I]);
-
   // Handle any function attribute group forward references.
   for (std::map<Value*, std::vector<unsigned> >::iterator
          I = ForwardRefAttrGroups.begin(), E = ForwardRefAttrGroups.end();
@@ -205,6 +202,9 @@ bool LLParser::ValidateEndOfModule() {
       N.second->resolveCycles();
   }
 
+  for (unsigned I = 0, E = InstsWithTBAATag.size(); I < E; I++)
+    UpgradeInstWithTBAATag(InstsWithTBAATag[I]);
+
   // Look for intrinsic functions and CallInst that need to be upgraded
   for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; )
     UpgradeCallsToIntrinsic(&*FI++); // must be post-increment, as we remove
@@ -601,6 +601,7 @@ bool LLParser::ParseMDString(MDString *&Result) {
 //   ::= '!' MDNodeNumber
 bool LLParser::ParseMDNodeID(MDNode *&Result) {
   // !{ ..., !42, ... }
+  LocTy IDLoc = Lex.getLoc();
   unsigned MID = 0;
   if (ParseUInt32(MID))
     return true;
@@ -613,7 +614,7 @@ bool LLParser::ParseMDNodeID(MDNode *&Result) {
 
   // Otherwise, create MDNode forward reference.
   auto &FwdRef = ForwardRefMDNodes[MID];
-  FwdRef = std::make_pair(MDTuple::getTemporary(Context, None), Lex.getLoc());
+  FwdRef = std::make_pair(MDTuple::getTemporary(Context, None), IDLoc);
 
   Result = FwdRef.first.get();
   NumberedMetadata[MID].reset(Result);
diff --git a/test/Assembler/invalid-mdnode-badref.ll b/test/Assembler/invalid-mdnode-badref.ll
index cfa03e0b3c6..5c28ef05493 100644
--- a/test/Assembler/invalid-mdnode-badref.ll
+++ b/test/Assembler/invalid-mdnode-badref.ll
@@ -1,5 +1,5 @@
 ; RUN: not llvm-as < %s -disable-output 2>&1 | FileCheck %s
 !named = !{!0}
 
-; CHECK: [[@LINE+1]]:14: error: use of undefined metadata '!1'
+; CHECK: [[@LINE+1]]:13: error: use of undefined metadata '!1'
 !0 = !{!0, !1}
diff --git a/test/Assembler/missing-tbaa.ll b/test/Assembler/missing-tbaa.ll
new file mode 100644
index 00000000000..38fe754b603
--- /dev/null
+++ b/test/Assembler/missing-tbaa.ll
@@ -0,0 +1,11 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+; Check that !tbaa upgrade doesn't crash on undefined metadata (it should give
+; an error).
+
+define void @foo() {
+entry:
+  store i8 undef, i8* undef,
+; CHECK: :[[@LINE+1]]:10: error: use of undefined metadata '!1'
+  !tbaa !1
+  unreachable
+}
-- 
2.11.0