IR: Make MDNode::dump() useful by adding addresses

It's horrible to inspect `MDNode`s in a debugger.  All of their operands
that are `MDNode`s get dumped as `<badref>`, since we can't assign
metadata slots in the context of a `Metadata::dump()`.  (Why not?  Why
not assign numbers lazily?  Because then each time you called `dump()`,
a given `MDNode` could have a different lazily assigned number.)

Fortunately, the C memory model gives us perfectly good identifiers for
`MDNode`.  Add pointer addresses to the dumps, transforming this:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <badref>, null}

    (lldb) e ((MDNode*)N->getOperand(2))->dump()
    !{i32 4, !"foo"}

into:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <0x100706ee0>, null}

    (lldb) e ((MDNode*)0x100706ee0)->dump()
    !{i32 4, !"foo"}

and this:

    (lldb) e N->dump()
    0x101200248 = !{<badref>, <badref>, <badref>, <badref>, <badref>}

    (lldb) e N->getOperand(0)
    (const llvm::MDOperand) $0 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(1)
    (const llvm::MDOperand) $1 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(2)
    (const llvm::MDOperand) $2 = {
      MD = 0x0000000101200058
    }
    (lldb) e N->getOperand(3)
    (const llvm::MDOperand) $3 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(4)
    (const llvm::MDOperand) $4 = {
      MD = 0x0000000101200058
    }
    (lldb) e ((MDNode*)0x00000001012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x0000000101200058)->dump()
    !{null}

into:

    (lldb) e N->dump()
    !{<0x1012004e0>, <0x1012004e0>, <0x101200058>, <0x1012004e0>, <0x101200058>}

    (lldb) e ((MDNode*)0x1012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x101200058)->dump()
    !{null}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224325 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith 2014-12-16 07:09:37 +00:00
parent d0e68dcf17
commit 2ebd1efc08
2 changed files with 42 additions and 1 deletions

View File

@ -1362,7 +1362,9 @@ static void WriteAsOperandInternal(raw_ostream &Out, const Metadata *MD,
Machine = new SlotTracker(Context);
int Slot = Machine->getMetadataSlot(N);
if (Slot == -1)
Out << "<badref>";
// Give the pointer value instead of "badref", since this comes up all
// the time when debugging.
Out << "<" << N << ">";
else
Out << '!' << Slot;
return;

View File

@ -22,6 +22,12 @@ namespace {
class MetadataTest : public testing::Test {
protected:
LLVMContext Context;
MDNode *getNode() { return MDNode::get(Context, None); }
MDNode *getNode(Metadata *MD) { return MDNode::get(Context, MD); }
MDNode *getNode(Metadata *MD1, Metadata *MD2) {
Metadata *MDs[] = {MD1, MD2};
return MDNode::get(Context, MDs);
}
};
typedef MetadataTest MDStringTest;
@ -163,6 +169,39 @@ TEST_F(MDNodeTest, SelfReference) {
}
}
TEST_F(MDNodeTest, Print) {
Constant *C = ConstantInt::get(Type::getInt32Ty(Context), 7);
MDString *S = MDString::get(Context, "foo");
MDNode *N0 = getNode();
MDNode *N1 = getNode(N0);
MDNode *N2 = getNode(N0, N1);
Metadata *Args[] = {ConstantAsMetadata::get(C), S, nullptr, N0, N1, N2};
MDNode *N = MDNode::get(Context, Args);
std::string Expected;
{
raw_string_ostream OS(Expected);
OS << "metadata !{";
C->printAsOperand(OS);
OS << ", ";
S->printAsOperand(OS, false);
OS << ", null";
MDNode *Nodes[] = {N0, N1, N2};
for (auto *Node : Nodes)
OS << ", <" << (void *)Node << ">";
OS << "}\n";
}
std::string Actual;
{
raw_string_ostream OS(Actual);
N->print(OS);
}
EXPECT_EQ(Expected, Actual);
}
typedef MetadataTest MetadataAsValueTest;
TEST_F(MetadataAsValueTest, MDNode) {