BTF supports 64-bits enumerators with following encoding:
struct btf_type:
name_off: 0 or offset to a valid C identifier
info.kind_flag: 0 for unsigned, 1 for signed
info.kind: BTF_KIND_ENUM64
info.vlen: number of enum values
size: 1/2/4/8
The btf_type is followed by info.vlen number of:
struct btf_enum64
{
uint32_t name_off; /* Offset in string section of enumerator name. */
uint32_t val_lo32; /* lower 32-bit value for a 64-bit value Enumerator */
uint32_t val_hi32; /* high 32-bit value for a 64-bit value Enumerator */
};
So, a new btf_enum64 structure was added to represent BTF_KIND_ENUM64
and a new field dtd_enum_unsigned in ctf_dtdef structure to distinguish
when CTF enum is a signed or unsigned type, later that information is
used to encode the BTF enum type.
gcc/ChangeLog:
* btfout.cc (btf_calc_num_vbytes): Compute enumeration size depending of
enumerator type btf_enum{,64}.
(btf_asm_type): Update btf_kflag according to enumeration type sign
using dtd_enum_unsigned field for both: BTF_KIND_ENUM{,64}.
(btf_asm_enum_const): New argument to represent the size of
the BTF enum type, writing the enumerator constant value for
32 bits, if it's 64 bits then explicitly writes lower 32-bits
value and higher 32-bits value.
(output_asm_btf_enum_list): Add enumeration size argument.
* ctfc.cc (ctf_add_enum): New argument to represent CTF enum
basic information.
(ctf_add_generic): Use of ei_{name. size, unsigned} to build the
dtd structure containing enumeration information.
(ctf_add_enumerator): Update comment mention support for BTF
enumeration in 64-bits.
* dwarf2ctf.cc (gen_ctf_enumeration_type): Extract signedness
for enumeration type and use it in ctf_add_enum.
* ctfc.h (ctf_dmdef): Update dmd_value to HOST_WIDE_INT to allow
use 32/64 bits enumerators.
information.
(ctf_dtdef): New field to describe enum signedness.
include/
* btf.h (btf_enum64): Add new definition and new symbolic
constant to BTF_KIND_ENUM64 and BTF_KF_ENUM_{UN,}SIGNED.
gcc/testsuite/ChangeLog:
* gcc.dg/debug/btf/btf-enum-1.c: Update testcase, with correct
info.kflags encoding.
* gcc.dg/debug/btf/btf-enum64-1.c: New testcase.
Guillermo E. Martinez
8422861bdd