[Metadata] Extend 'count' field of DISubrange to take a metadata node
Summary:
This patch extends the DISubrange 'count' field to take either a
(signed) constant integer value or a reference to a DILocalVariable
or DIGlobalVariable.
This is patch [1/3] in a series to extend LLVM's DISubrange Metadata
node to support debugging of C99 variable length arrays and vectors with
runtime length like the Scalable Vector Extension for AArch64. It is
also a first step towards representing more complex cases like arrays
in Fortran.
Reviewers: echristo, pcc, aprantl, dexonsmith, clayborg, kristof.beyls, dblaikie
Reviewed By: aprantl
Subscribers: rnk, probinson, fhahn, aemerson, rengolin, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D41695
llvm-svn: 323313
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 11c28ba..bee4d11 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -1325,7 +1325,9 @@
const DISubrange *Subrange = cast<DISubrange>(Element);
assert(Subrange->getLowerBound() == 0 &&
"codeview doesn't support subranges with lower bounds");
- int64_t Count = Subrange->getCount();
+ int64_t Count = -1;
+ if (auto *CI = Subrange->getCount().dyn_cast<ConstantInt*>())
+ Count = CI->getSExtValue();
// Forward declarations of arrays without a size and VLAs use a count of -1.
// Emit a count of zero in these cases to match what MSVC does for arrays