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| author | Adrian Prantl <aprantl@apple.com> | 2020-01-16 14:21:03 -0800 |
|---|---|---|
| committer | Hans Wennborg <hans@chromium.org> | 2020-02-19 14:20:33 +0100 |
| commit | 7751f0c191518b377d9b71bdd17281abec83945a (patch) | |
| tree | 0ccae336d37723d00d0053ec2dd0ce0d0ca7d5ec /lldb/source | |
| parent | d5f8656a68c25e93c5c8f03e0670fecb16609d40 (diff) | |
| download | bcm5719-llvm-7751f0c191518b377d9b71bdd17281abec83945a.tar.gz bcm5719-llvm-7751f0c191518b377d9b71bdd17281abec83945a.zip | |
Add testing for DW_OP_piece and fix a bug with small Scalar values.
By switching to Scalars that are backed by explicitly-sized APInts we
can avoid a bug that increases the buffer reserved for a small piece
to the next-largest host integer type.
This manifests as "DW_OP_piece for offset foo but top of stack is of size bar".
Differential Revision: https://reviews.llvm.org/D72879
(cherry picked from commit 7b0d58e339b271e3b1d9dc14b781b57fa0262e3a)
Diffstat (limited to 'lldb/source')
| -rw-r--r-- | lldb/source/Expression/DWARFExpression.cpp | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp index 69c84640ef9..0f8eea754c2 100644 --- a/lldb/source/Expression/DWARFExpression.cpp +++ b/lldb/source/Expression/DWARFExpression.cpp @@ -2128,7 +2128,8 @@ bool DWARFExpression::Evaluate( case Value::eValueTypeScalar: { uint32_t bit_size = piece_byte_size * 8; uint32_t bit_offset = 0; - if (!curr_piece_source_value.GetScalar().ExtractBitfield( + Scalar &scalar = curr_piece_source_value.GetScalar(); + if (!scalar.ExtractBitfield( bit_size, bit_offset)) { if (error_ptr) error_ptr->SetErrorStringWithFormat( @@ -2139,7 +2140,14 @@ bool DWARFExpression::Evaluate( .GetByteSize()); return false; } - curr_piece = curr_piece_source_value; + // Create curr_piece with bit_size. By default Scalar + // grows to the nearest host integer type. + llvm::APInt fail_value(1, 0, false); + llvm::APInt ap_int = scalar.UInt128(fail_value); + assert(ap_int.getBitWidth() >= bit_size); + llvm::ArrayRef<uint64_t> buf{ap_int.getRawData(), + ap_int.getNumWords()}; + curr_piece.GetScalar() = Scalar(llvm::APInt(bit_size, buf)); } break; case Value::eValueTypeVector: { @@ -2161,7 +2169,7 @@ bool DWARFExpression::Evaluate( if (op_piece_offset == 0) { // This is the first piece, we should push it back onto the stack // so subsequent pieces will be able to access this piece and add - // to it + // to it. if (pieces.AppendDataToHostBuffer(curr_piece) == 0) { if (error_ptr) error_ptr->SetErrorString("failed to append piece data"); @@ -2169,7 +2177,7 @@ bool DWARFExpression::Evaluate( } } else { // If this is the second or later piece there should be a value on - // the stack + // the stack. if (pieces.GetBuffer().GetByteSize() != op_piece_offset) { if (error_ptr) error_ptr->SetErrorStringWithFormat( |
