[llvm] r257825 - [Verifier] Check parentage of GVs in dbg metadata

[Keno Fischer via llvm-commits]

Author: kfischer
Date: Thu Jan 14 16:42:02 2016
New Revision: 257825

URL: http://llvm.org/viewvc/llvm-project?rev=257825&view=rev
Log:
[Verifier] Check parentage of GVs in dbg metadata

Summary:
Before this the Verifier didn't complain if the GlobalVariable
referenced from a DIGlobalVariable was not in fact in the correct
module (it would crash while writing bitcode though). Fix this by
always checking parantage of GlobalValues while walking constant
expressions and changing the DIGlobalVariable visitor to also
visit the constant it contains.

Reviewers: rafael
Differential Revision: http://reviews.llvm.org/D16059

Modified:
    llvm/trunk/lib/IR/Verifier.cpp
    llvm/trunk/unittests/IR/VerifierTest.cpp

Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=257825&r1=257824&r2=257825&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Thu Jan 14 16:42:02 2016
@@ -1097,6 +1097,7 @@ void Verifier::visitDIGlobalVariable(con
     Assert(isa<ConstantAsMetadata>(V) &&
                !isa<Function>(cast<ConstantAsMetadata>(V)->getValue()),
            "invalid global varaible ref", &N, V);
+    visitConstantExprsRecursively(cast<ConstantAsMetadata>(V)->getValue());
   }
   if (auto *Member = N.getRawStaticDataMemberDeclaration()) {
     Assert(isa<DIDerivedType>(Member), "invalid static data member declaration",
@@ -1561,13 +1562,19 @@ void Verifier::visitConstantExprsRecursi
     if (const auto *CE = dyn_cast<ConstantExpr>(C))
       visitConstantExpr(CE);
 
+    if (const auto *GV = dyn_cast<GlobalValue>(C)) {
+      // Global Values get visited separately, but we do need to make sure
+      // that the global value is in the correct module
+      Assert(GV->getParent() == M, "Referencing global in another module!",
+             EntryC, M, GV, GV->getParent());
+      continue;
+    }
+
     // Visit all sub-expressions.
     for (const Use &U : C->operands()) {
       const auto *OpC = dyn_cast<Constant>(U);
       if (!OpC)
         continue;
-      if (isa<GlobalValue>(OpC))
-        continue; // Global values get visited separately.
       if (!ConstantExprVisited.insert(OpC).second)
         continue;
       Stack.push_back(OpC);

Modified: llvm/trunk/unittests/IR/VerifierTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/VerifierTest.cpp?rev=257825&r1=257824&r2=257825&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/VerifierTest.cpp (original)
+++ llvm/trunk/unittests/IR/VerifierTest.cpp Thu Jan 14 16:42:02 2016
@@ -9,6 +9,7 @@
 
 #include "llvm/IR/Verifier.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalAlias.h"
@@ -119,7 +120,28 @@ TEST(VerifierTest, CrossModuleRef) {
   F3->eraseFromParent();
 }
 
+TEST(VerifierTest, CrossModuleMetadataRef) {
+  LLVMContext &C = getGlobalContext();
+  Module M1("M1", C);
+  Module M2("M2", C);
+  GlobalVariable *newGV =
+      new GlobalVariable(M1, Type::getInt8Ty(C), false,
+                         GlobalVariable::ExternalLinkage, NULL, "Some Global");
+
+  DIBuilder dbuilder(M2);
+  auto CU = dbuilder.createCompileUnit(dwarf::DW_LANG_Julia, "test.jl", ".",
+                                       "unittest", false, "", 0);
+  auto File = dbuilder.createFile("test.jl", ".");
+  auto Ty = dbuilder.createBasicType("Int8", 8, 8, dwarf::DW_ATE_signed);
+  dbuilder.createGlobalVariable(CU, "_SOME_GLOBAL", "_SOME_GLOBAL", File, 1, Ty,
+                                false, newGV);
+  dbuilder.finalize();
 
-
+  std::string Error;
+  raw_string_ostream ErrorOS(Error);
+  EXPECT_TRUE(verifyModule(M2, &ErrorOS));
+  EXPECT_TRUE(StringRef(ErrorOS.str())
+                  .startswith("Referencing global in another module!"));
+}
 }
 }