This patch makes the DWARF-to-CTF conversion process aware of the new DW_TAG_GNU annotation DIEs. The DIEs are converted to an internal-only CTF representation as appropriate and added to the compilation unit CTF container.
gcc/ * dwarf2ctf.cc (handle_debug_annotations): New function. (gen_ctf_sou_type): Call it here, if appropriate. Don't try to create member types for children that are not DW_TAG_member. (gen_ctf_function_type): Call handle_debug_annotations if appropriate. (gen_ctf_variable): Likewise. (gen_ctf_function): Likewise. (gen_ctf_type): Likewise. --- gcc/dwarf2ctf.cc | 112 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 111 insertions(+), 1 deletion(-) diff --git a/gcc/dwarf2ctf.cc b/gcc/dwarf2ctf.cc index 393aa92d71d..65714e5d3b9 100644 --- a/gcc/dwarf2ctf.cc +++ b/gcc/dwarf2ctf.cc @@ -32,6 +32,12 @@ along with GCC; see the file COPYING3. If not see static ctf_id_t gen_ctf_type (ctf_container_ref, dw_die_ref); +static void +gen_ctf_variable (ctf_container_ref, dw_die_ref); + +static void +handle_debug_annotations (ctf_container_ref, dw_die_ref, ctf_id_t, int); + /* All the DIE structures we handle come from the DWARF information generated by GCC. However, there are three situations where we need to create our own created DIE structures because GCC doesn't @@ -547,6 +553,7 @@ gen_ctf_sou_type (ctf_container_ref ctfc, dw_die_ref sou, uint32_t kind) /* Now process the struct members. */ { dw_die_ref c; + int idx = 0; c = dw_get_die_child (sou); if (c) @@ -559,6 +566,12 @@ gen_ctf_sou_type (ctf_container_ref ctfc, dw_die_ref sou, uint32_t kind) c = dw_get_die_sib (c); + if (dw_get_die_tag (c) != DW_TAG_member) + continue; + + if (c == dw_get_die_child (sou)) + idx = 0; + field_name = get_AT_string (c, DW_AT_name); field_type = ctf_get_AT_type (c); field_location = ctf_get_AT_data_member_location (c); @@ -626,6 +639,12 @@ gen_ctf_sou_type (ctf_container_ref ctfc, dw_die_ref sou, uint32_t kind) field_name, field_type_id, field_location); + + /* Handle BTF tags on the member. */ + if (btf_debuginfo_p ()) + handle_debug_annotations (ctfc, c, sou_type_id, idx); + + idx++; } while (c != dw_get_die_child (sou)); } @@ -716,6 +735,9 @@ gen_ctf_function_type (ctf_container_ref ctfc, dw_die_ref function, arg_type = gen_ctf_type (ctfc, ctf_get_AT_type (c)); /* Add the argument to the existing CTF function type. */ ctf_add_function_arg (ctfc, function, arg_name, arg_type); + + if (btf_debuginfo_p ()) + handle_debug_annotations (ctfc, c, function_type_id, i - 1); } else /* This is a local variable. Ignore. */ @@ -828,6 +850,10 @@ gen_ctf_variable (ctf_container_ref ctfc, dw_die_ref die) /* Skip updating the number of global objects at this time. This is updated later after pre-processing as some CTF variable records although generated now, will not be emitted later. [PR105089]. */ + + /* Handle any BTF tags on the variable. */ + if (btf_debuginfo_p ()) + handle_debug_annotations (ctfc, die, CTF_NULL_TYPEID, -1); } /* Add a CTF function record for the given input DWARF DIE. */ @@ -845,8 +871,12 @@ gen_ctf_function (ctf_container_ref ctfc, dw_die_ref die) counter. Note that DWARF encodes function types in both DW_TAG_subroutine_type and DW_TAG_subprogram in exactly the same way. */ - (void) gen_ctf_function_type (ctfc, die, true /* from_global_func */); + function_type_id = gen_ctf_function_type (ctfc, die, true /* from_global_func */); ctfc->ctfc_num_global_funcs += 1; + + /* Handle any BTF tags on the function itself. */ + if (btf_debuginfo_p ()) + handle_debug_annotations (ctfc, die, function_type_id, -1); } /* Add CTF type record(s) for the given input DWARF DIE and return its type id. @@ -923,6 +953,10 @@ gen_ctf_type (ctf_container_ref ctfc, dw_die_ref die) break; } + /* Handle any BTF tags on the type. */ + if (btf_debuginfo_p () && !unrecog_die) + handle_debug_annotations (ctfc, die, type_id, -1); + /* For all types unrepresented in CTF, use an explicit CTF type of kind CTF_K_UNKNOWN. */ if ((type_id == CTF_NULL_TYPEID) && (!unrecog_die)) @@ -931,6 +965,82 @@ gen_ctf_type (ctf_container_ref ctfc, dw_die_ref die) return type_id; } +/* BTF support. Handle any annotations attached to a given DIE, and generate + intermediate CTF types for them. BTF tags are inserted into the type chain + at this point. The return value is the CTF type ID of the last type tag + created (for type chaining), or the same as the argument TYPE_ID if there are + no type tags. + Note that despite the name, the BTF spec seems to allow decl tags on types + as well as declarations. */ + +static void +handle_debug_annotations (ctf_container_ref ctfc, dw_die_ref die, + ctf_id_t type_id, int component_idx) +{ + dw_die_ref c; + const char * name = NULL; + const char * value = NULL; + ctf_dtdef_ref dtd = ctf_dtd_lookup (ctfc, die); + ctf_id_t target_id, tag_id; + + if (dtd) + target_id = dtd->dtd_data.ctti_type; + else + target_id = CTF_NULL_TYPEID; + + c = dw_get_die_child (die); + if (c) + do + { + if (dw_get_die_tag (c) != DW_TAG_GNU_annotation) + { + c = dw_get_die_sib (c); + continue; + } + + name = get_AT_string (c, DW_AT_name); + + /* BTF decl tags add an arbitrary annotation to the thing they + annotate. The annotated thing could be a variable or a type. */ + if (strcmp (name, "debug_annotate_decl") == 0) + { + value = get_AT_string (c, DW_AT_const_value); + if (!ctf_type_exists (ctfc, c, &tag_id)) + (void) ctf_add_reftype (ctfc, CTF_ADD_ROOT, value, + type_id, CTF_K_DECL_TAG, c); + ctf_dtdef_ref dtd = ctf_dtd_lookup (ctfc, c); + dtd->dtd_u.dtu_btfnote.component_idx = component_idx; + } + + /* BTF type tags are part of the type chain similar to cvr quals. + But the type tag DIEs are children of the DIEs they annotate. + + For each type tag on this type, create a CTF type for it and + insert it into the type chain: + - The first tag refers to the type referred to by the parent. + - Each subsequent tag refers to the prior tag. + - The parent type is updated to refer to the last tag. + + Given this type chain requirement, the representation of type + tags in BTF only makes sense for pointer types. Should this be + enforced here? */ + else if (strcmp (name, "debug_annotate_type") == 0) + { + gcc_assert (dtd); + value = get_AT_string (c, DW_AT_const_value); + + if (!ctf_type_exists (ctfc, c, &tag_id)) + tag_id = ctf_add_reftype (ctfc, CTF_ADD_ROOT, value, + target_id, CTF_K_TYPE_TAG, c); + + dtd->dtd_data.ctti_type = tag_id; + target_id = tag_id; + } + c = dw_get_die_sib (c); + } + while (c != dw_get_die_child (die)); +} + /* Prepare for output and write out the CTF debug information. */ static void -- 2.36.1