From: Duncan P. N. Exon Smith <dexonsmith@apple.com>
Date: Sat, 6 Dec 2014 02:29:44 +0000 (+0000)
Subject: IR: Disallow function-local metadata attachments
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=09ba28c27c1d606d25924cf36927d433d7b2dc8c;p=oota-llvm.git

IR: Disallow function-local metadata attachments

Metadata attachments to instructions cannot be function-local.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223574 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 93eb490619f..f44af673fcd 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -62,6 +62,8 @@ bool LLParser::ValidateEndOfModule() {
             NumberedMetadata[SlotNo] == nullptr)
           return Error(MDList[i].Loc, "use of undefined metadata '!" +
                        Twine(SlotNo) + "'");
+        assert(!NumberedMetadata[SlotNo]->isFunctionLocal() &&
+               "Unexpected function-local metadata");
         Inst->setMetadata(MDList[i].MDKind, NumberedMetadata[SlotNo]);
       }
     }
@@ -1529,6 +1531,8 @@ bool LLParser::ParseInstructionMetadata(Instruction *Inst,
       if (ParseMetadataListValue(ID, PFS))
         return true;
       assert(ID.Kind == ValID::t_MDNode);
+      if (ID.MDNodeVal->isFunctionLocal())
+        return TokError("unexpected function-local metadata");
       Inst->setMetadata(MDK, ID.MDNodeVal);
     } else {
       unsigned NodeID = 0;
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 9f6d02f88db..72f823c2e3e 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2359,8 +2359,12 @@ std::error_code BitcodeReader::ParseMetadataAttachment() {
           MDKindMap.find(Kind);
         if (I == MDKindMap.end())
           return Error(BitcodeError::InvalidID);
-        Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
-        Inst->setMetadata(I->second, cast<MDNode>(Node));
+        MDNode *Node = cast<MDNode>(MDValueList.getValueFwdRef(Record[i+1]));
+        if (Node->isFunctionLocal())
+          // Drop the attachment.  This used to be legal, but there's no
+          // upgrade path.
+          break;
+        Inst->setMetadata(I->second, Node);
         if (I->second == LLVMContext::MD_tbaa)
           InstsWithTBAATag.push_back(Inst);
       }
diff --git a/lib/IR/Metadata.cpp b/lib/IR/Metadata.cpp
index 45d61a15a6b..e5dfaec74e5 100644
--- a/lib/IR/Metadata.cpp
+++ b/lib/IR/Metadata.cpp
@@ -639,6 +639,8 @@ void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
   
   // Handle the case when we're adding/updating metadata on an instruction.
   if (Node) {
+    assert(!Node->isFunctionLocal() &&
+           "Function-local metadata cannot be attached to instructions");
     LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
     assert(!Info.empty() == hasMetadataHashEntry() &&
            "HasMetadata bit is wonked");
diff --git a/test/Feature/metadata.ll b/test/Feature/metadata.ll
index 2a857bb9c6b..f83b7fe9c32 100644
--- a/test/Feature/metadata.ll
+++ b/test/Feature/metadata.ll
@@ -5,7 +5,7 @@ define void @foo(i32 %x) {
   call void @llvm.zonk(metadata !1, i64 0, metadata !1)
   store i32 0, i32* null, !whatever !0, !whatever_else !{}, !more !{metadata !"hello"}
   store i32 0, i32* null, !whatever !{metadata !"hello", metadata !1, metadata !{}, metadata !2}
-  ret void, !whatever !{i32 %x}
+  ret void
 }
 
 declare void @llvm.zonk(metadata, i64, metadata) nounwind readnone
diff --git a/test/Linker/metadata-a.ll b/test/Linker/metadata-a.ll
index 5a9d2e40b94..76a8c8cbfc7 100644
--- a/test/Linker/metadata-a.ll
+++ b/test/Linker/metadata-a.ll
@@ -1,15 +1,15 @@
 ; RUN: llvm-link %s %p/metadata-b.ll -S -o - | FileCheck %s
 
 ; CHECK: define void @foo(i32 %a)
-; CHECK: ret void, !attach !0, !also !{i32 %a}
+; CHECK: ret void, !attach !0
 ; CHECK: define void @goo(i32 %b)
-; CHECK: ret void, !attach !1, !and !{i32 %b}
+; CHECK: ret void, !attach !1
 ; CHECK: !0 = metadata !{i32 524334, void (i32)* @foo}
 ; CHECK: !1 = metadata !{i32 524334, void (i32)* @goo}
 
 define void @foo(i32 %a) nounwind {
 entry:
-  ret void, !attach !0, !also !{ i32 %a }
+  ret void, !attach !0
 }
 
 !0 = metadata !{i32 524334, void (i32)* @foo}
diff --git a/test/Linker/metadata-b.ll b/test/Linker/metadata-b.ll
index ef0270af075..35d4f66ccba 100644
--- a/test/Linker/metadata-b.ll
+++ b/test/Linker/metadata-b.ll
@@ -3,7 +3,7 @@
 
 define void @goo(i32 %b) nounwind {
 entry:
-  ret void, !attach !0, !and !{ i32 %b }
+  ret void, !attach !0
 }
 
 !0 = metadata !{i32 524334, void (i32)* @goo}