[DEBUG_INFO][NVPTX] Generate DW_AT_address_class to get the values in debugger.
Summary:
According to
https://docs.nvidia.com/cuda/archive/10.0/ptx-writers-guide-to-interoperability/index.html#cuda-specific-dwarf,
the compiler should emit the DW_AT_address_class attribute for all
variable and parameter. It means, that DW_AT_address_class attribute
should be used in the non-standard way to support compatibility with the
cuda-gdb debugger.
Clang is able to generate the information about the variable address
class. This information is emitted as the expression sequence
`DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef`. The patch
tries to find all such expressions and transform them into
`DW_AT_address_class <DWARF Address Space>` if target is NVPTX and the debugger is gdb.
If the expression is not found, then default values are used. For the
local variables <DWARF Address Space> is set to ADDR_local_space(6), for
the globals <DWARF Address Space> is set to ADDR_global_space(5). The
values are taken from the table in the same section 5.2. CUDA-Specific
DWARF Definitions.
Reviewers: echristo, probinson
Subscribers: jholewinski, aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D57157
llvm-svn: 353203
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
index 40e6873..385f6e7 100644
--- a/llvm/include/llvm/IR/DebugInfoMetadata.h
+++ b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -2510,6 +2510,12 @@
/// return true with an offset of zero.
bool extractIfOffset(int64_t &Offset) const;
+ /// Checks if the last 4 elements of the expression are DW_OP_constu <DWARF
+ /// Address Space> DW_OP_swap DW_OP_xderef and extracts the <DWARF Address
+ /// Space>.
+ static const DIExpression *extractAddressClass(const DIExpression *Expr,
+ unsigned &AddrClass);
+
/// Constants for DIExpression::prepend.
enum { NoDeref = false, WithDeref = true, WithStackValue = true };