From 9a5cd424d5f06fb5293eb264456d89343c557558 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 17 Feb 2016 23:48:20 -0700 Subject: qapi: Visit variants in visit_type_FOO_fields() We initially created the static visit_type_FOO_fields() helper function for reuse of code - we have cases where the initial setup for a visit has different allocation (depending on whether the fields represent a stand-alone type or are embedded as part of a larger type), but where the actual field visits are identical once a pointer is available. Up until the previous patch, visit_type_FOO_fields() was only used for structs (no variants), so it was covering every field for each type where it was emitted. Meanwhile, the code for visiting unions looks like: static visit_type_U_fields() { visit base; visit local_members; } visit_type_U() { visit_start_struct(); visit_type_U_fields(); visit variants; visit_end_struct(); } which splits the fields of the union visit across two functions. Move the code to visit variants to live inside visit_type_U_fields(), while making it conditional on having variants so that all other instances of the helper function remain unchanged. This is also a step closer towards unifying struct and union visits, and towards allowing one union type to be the branch of another flat union. The resulting diff to the generated code is a bit hard to read, but it can be verified that it touches only union types, and that the end result is the following general structure: static visit_type_U_fields() { visit base; visit local_members; visit variants; } visit_type_U() { visit_start_struct(); visit_type_U_fields(); visit_end_struct(); } Signed-off-by: Eric Blake Message-Id: <1455778109-6278-7-git-send-email-eblake@redhat.com> [gen_visit_struct_fields() parameter variants made mandatory] Signed-off-by: Markus Armbruster --- scripts/qapi-visit.py | 106 +++++++++++++++++++++++++------------------------- 1 file changed, 54 insertions(+), 52 deletions(-) (limited to 'scripts') diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py index 1051710ab1..5e91342101 100644 --- a/scripts/qapi-visit.py +++ b/scripts/qapi-visit.py @@ -71,11 +71,16 @@ static void visit_type_implicit_%(c_type)s(Visitor *v, %(c_type)s **obj, Error * return ret -def gen_visit_struct_fields(name, base, members): +def gen_visit_struct_fields(name, base, members, variants): ret = '' if base: ret += gen_visit_fields_decl(base) + if variants: + for var in variants.variants: + # Ugly special case for simple union TODO get rid of it + if not var.simple_union_type(): + ret += gen_visit_implicit_struct(var.type) struct_fields_seen.add(name) ret += mcgen(''' @@ -96,8 +101,49 @@ static void visit_type_%(c_name)s_fields(Visitor *v, %(c_name)s **obj, Error **e ret += gen_visit_fields(members, prefix='(*obj)->') - # 'goto out' produced for base, and by gen_visit_fields() for each member - if base or members: + if variants: + ret += mcgen(''' + if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) { + goto out; + } + switch ((*obj)->%(c_name)s) { +''', + c_name=c_name(variants.tag_member.name)) + + for var in variants.variants: + # TODO ugly special case for simple union + simple_union_type = var.simple_union_type() + ret += mcgen(''' + case %(case)s: +''', + case=c_enum_const(variants.tag_member.type.name, + var.name, + variants.tag_member.type.prefix)) + if simple_union_type: + ret += mcgen(''' + visit_type_%(c_type)s(v, "data", &(*obj)->u.%(c_name)s, &err); +''', + c_type=simple_union_type.c_name(), + c_name=c_name(var.name)) + else: + ret += mcgen(''' + visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err); +''', + c_type=var.type.c_name(), + c_name=c_name(var.name)) + ret += mcgen(''' + break; +''') + + ret += mcgen(''' + default: + abort(); + } +''') + + # 'goto out' produced for base, by gen_visit_fields() for each member, + # and if variants were present + if base or members or variants: ret += mcgen(''' out: @@ -110,7 +156,7 @@ out: def gen_visit_struct(name, base, members): - ret = gen_visit_struct_fields(name, base, members) + ret = gen_visit_struct_fields(name, base, members, None) # FIXME: if *obj is NULL on entry, and visit_start_struct() assigns to # *obj, but then visit_type_FOO_fields() fails, we should clean up *obj @@ -239,12 +285,7 @@ out: def gen_visit_union(name, base, members, variants): - ret = gen_visit_struct_fields(name, base, members) - - for var in variants.variants: - # Ugly special case for simple union TODO get rid of it - if not var.simple_union_type(): - ret += gen_visit_implicit_struct(var.type) + ret = gen_visit_struct_fields(name, base, members, variants) ret += mcgen(''' @@ -260,54 +301,15 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error goto out_obj; } visit_type_%(c_name)s_fields(v, obj, &err); -''', - c_name=c_name(name)) - ret += gen_err_check(label='out_obj') - ret += mcgen(''' - if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) { - goto out_obj; - } - switch ((*obj)->%(c_name)s) { -''', - c_name=c_name(variants.tag_member.name)) - - for var in variants.variants: - # TODO ugly special case for simple union - simple_union_type = var.simple_union_type() - ret += mcgen(''' - case %(case)s: -''', - case=c_enum_const(variants.tag_member.type.name, - var.name, - variants.tag_member.type.prefix)) - if simple_union_type: - ret += mcgen(''' - visit_type_%(c_type)s(v, "data", &(*obj)->u.%(c_name)s, &err); -''', - c_type=simple_union_type.c_name(), - c_name=c_name(var.name)) - else: - ret += mcgen(''' - visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err); -''', - c_type=var.type.c_name(), - c_name=c_name(var.name)) - ret += mcgen(''' - break; -''') - - ret += mcgen(''' - default: - abort(); - } -out_obj: error_propagate(errp, err); err = NULL; +out_obj: visit_end_struct(v, &err); out: error_propagate(errp, err); } -''') +''', + c_name=c_name(name)) return ret -- cgit v1.2.1