From d94d5bbbf91589aafbf9c902f3839d3a51db6484 Mon Sep 17 00:00:00 2001
From: "Duncan P. N. Exon Smith" <dexonsmith@apple.com>
Date: Fri, 20 Mar 2015 19:26:58 +0000
Subject: [PATCH] Verifier: Check that !dbg attachments have the right type

A WIP patch makes `DIDescriptor` accessors more strict, which in turn
causes the `DebugInfoFinder` to crash on wrongly typed `!dbg`
attachments.  Catch that error up front in
`Verifier::visitInstruction()`.

Also remove a test that we "handle" invalid `!dbg` attachments, added
back in r99938.  We don't want to handle those anymore.

Note: I'm *not* recursing and verifying the debug info graph reachable
from this node; that work is already done by `verifyDebugInfo()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232834 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/IR/Verifier.cpp                           |  7 ++++
 .../2010-03-30-InvalidDbgInfoCrash.ll         | 36 -------------------
 test/DebugInfo/location-verifier.ll           |  2 +-
 test/Verifier/dbg.ll                          | 12 +++++++
 4 files changed, 20 insertions(+), 37 deletions(-)
 delete mode 100644 test/DebugInfo/2010-03-30-InvalidDbgInfoCrash.ll
 create mode 100644 test/Verifier/dbg.ll

diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index ce765b14420..4f0e3388d58 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -2556,6 +2556,13 @@ void Verifier::visitInstruction(Instruction &I) {
            &I);
   }
 
+  // Don't recurse into !dbg attachments (leave that for verifyDebugInfo()),
+  // but at least check that it's a legal type.
+  if (MDNode *N = I.getDebugLoc().getAsMDNode()) {
+    Assert(isa<MDLocation>(N),
+           "invalid !dbg metadata attachment", &I, N);
+  }
+
   InstsInThisBlock.insert(&I);
 }
 
diff --git a/test/DebugInfo/2010-03-30-InvalidDbgInfoCrash.ll b/test/DebugInfo/2010-03-30-InvalidDbgInfoCrash.ll
deleted file mode 100644
index 8bc6c6a0b3a..00000000000
--- a/test/DebugInfo/2010-03-30-InvalidDbgInfoCrash.ll
+++ /dev/null
@@ -1,36 +0,0 @@
-; RUN: llc < %s -o /dev/null
-
-define void @baz(i32 %i) nounwind ssp {
-entry:
-  call void @llvm.dbg.declare(metadata !0, metadata !1, metadata !MDExpression()), !dbg !0
-  ret void, !dbg !0
-}
-
-declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
-
-!llvm.dbg.cu = !{!5}
-!llvm.module.flags = !{!22}
-
-!0 = !{{ [0 x i8] }** undef}
-!1 = !MDLocalVariable(tag: DW_TAG_auto_variable, name: "x", line: 11, scope: !2, file: !4, type: !9)
-!2 = distinct !MDLexicalBlock(line: 8, column: 0, file: !20, scope: !3)
-!3 = !MDSubprogram(name: "baz", linkageName: "baz", line: 8, isLocal: true, isDefinition: true, virtualIndex: 6, isOptimized: false, file: !20, scope: null, type: !6)
-!4 = !MDFile(filename: "2007-12-VarArrayDebug.c", directory: "/Users/sabre/llvm/test/FrontendC/")
-!5 = !MDCompileUnit(language: DW_LANG_C89, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: true, emissionKind: 0, file: !20, enums: !21, retainedTypes: !21)
-!6 = !MDSubroutineType(types: !7)
-!7 = !{null, !8}
-!8 = !MDBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
-!9 = !MDDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, file: !20, scope: !4, baseType: !10)
-!10 = !MDCompositeType(tag: DW_TAG_structure_type, line: 11, size: 8, align: 8, file: !20, scope: !3, elements: !11)
-!11 = !{!12}
-!12 = !MDDerivedType(tag: DW_TAG_member, name: "b", line: 11, size: 8, align: 8, file: !20, scope: !10, baseType: !13)
-!13 = !MDDerivedType(tag: DW_TAG_typedef, name: "A", line: 11, file: !20, scope: !3, baseType: !14)
-!14 = !MDCompositeType(tag: DW_TAG_array_type, size: 8, align: 8, file: !20, scope: !4, baseType: !15, elements: !16)
-!15 = !MDBasicType(tag: DW_TAG_base_type, name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
-!16 = !{!17}
-!17 = !MDSubrange(count: 1)
-!18 = !{!"llvm.mdnode.fwdref.19"}
-!19 = !{!"llvm.mdnode.fwdref.23"}
-!20 = !MDFile(filename: "2007-12-VarArrayDebug.c", directory: "/Users/sabre/llvm/test/FrontendC/")
-!21 = !{i32 0}
-!22 = !{i32 1, !"Debug Info Version", i32 3}
diff --git a/test/DebugInfo/location-verifier.ll b/test/DebugInfo/location-verifier.ll
index d35c7323669..f49fd591578 100644
--- a/test/DebugInfo/location-verifier.ll
+++ b/test/DebugInfo/location-verifier.ll
@@ -29,5 +29,5 @@ attributes #0 = { nounwind ssp uwtable }
 !11 = !{i32 1, !"PIC Level", i32 2}
 !12 = !{!"clang version 3.7.0 "}
 ; An old-style MDLocation should not pass verify.
-; CHECK: DISubprogram does not Verify
+; CHECK: invalid !dbg metadata attachment
 !13 = !{i32 2, i32 2, !4, null}
diff --git a/test/Verifier/dbg.ll b/test/Verifier/dbg.ll
new file mode 100644
index 00000000000..20b80ff2efe
--- /dev/null
+++ b/test/Verifier/dbg.ll
@@ -0,0 +1,12 @@
+; RUN: not llvm-as -disable-output <%s 2>&1 | FileCheck %s
+
+define void @foo() {
+  ret void, !dbg !{}
+}
+
+; CHECK: invalid !dbg metadata attachment
+; CHECK-NEXT: ret void, !dbg ![[LOC:[0-9]+]]
+; CHECK-NEXT: ![[LOC]] = !{}
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"Debug Info Version", i32 3}