Commit Graph

3 Commits

Author SHA1 Message Date
Adrian Prantl 9b23df63ec Implement DW_OP_convert
This patch adds basic support for DW_OP_convert[1] for integer
types. Recent versions of LLVM's optimizer may insert this opcode into
DWARF expressions. DW_OP_convert is effectively a type cast operation
that takes a reference to a base type DIE (or zero) and then casts the
value at the top of the DWARF stack to that type. Internally this
works by changing the bit size of the APInt that is used as backing
storage for LLDB's DWARF stack.

I managed to write a unit test for this by implementing a mock YAML
object file / module that takes debug info sections in yaml2obj
format.

[1] Typed DWARF stack. http://www.dwarfstd.org/ShowIssue.php?issue=140425.1

<rdar://problem/48167864>

Differential Revision: https://reviews.llvm.org/D67369

llvm-svn: 371532
2019-09-10 16:17:38 +00:00
Pavel Labath e588b8b664 DWARFExpression: Simplify class interface
Summary:
The DWARFExpression methods have a lot of arguments. This removes two of
them by removing the ability to slice the expression via two offset+size
parameters. This is a functionality that it is not always needed, and
when it is, we already have a different handy way of slicing a data
extractor which we can use instead.

Reviewers: JDevlieghere, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D66745

llvm-svn: 370027
2019-08-27 07:49:41 +00:00
Pavel Labath b07a799752 DWARFExpression: Fix implementation of DW_OP_pick
Summary:
The DWARF spec states that the DWARF stack arguments are numbered from
the top. Our implementation of DW_OP_pick was counting them from the
bottom.

This bug probably wasn't noticed because nobody (except my upcoming
postfix-to-DWARF converter) uses DW_OP_pick, but I've cross-checked with
gdb to confirm that counting from the top is the expected behavior.

This patch fixes the implementation to match the spec and gdb behavior
and adds a test.

Reviewers: jasonmolenda, clayborg

Subscribers: mgorny, aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D61182

llvm-svn: 359436
2019-04-29 10:55:22 +00:00