From d7bea75d35a44023efc9d481d3a1a2600677b2ef Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 29 Jan 2016 06:48:38 -0700 Subject: qapi: Avoid use of misnamed DO_UPCAST() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The macro DO_UPCAST() is incorrectly named: it converts from a parent class to a derived class (which is a downcast). Better, and more consistent with some of the other qapi visitors, is to use the container_of() macro through a to_FOO() helper. Names like 'to_ov()' may be a bit short, but for a static helper it doesn't hurt too much, and matches existing practice in files like qmp-input-visitor.c. Our current definition of container_of() is weaker than DO_UPCAST(), in that it does not require the derived class to have Visitor as its first member, but this does not hurt our usage patterns in qapi visitors. Signed-off-by: Eric Blake Reviewed-by: Marc-André Lureau Message-Id: <1454075341-13658-3-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster --- qapi/string-output-visitor.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'qapi/string-output-visitor.c') diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index b04cec4..b0313cb 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -67,6 +67,11 @@ struct StringOutputVisitor GList *ranges; }; +static StringOutputVisitor *to_sov(Visitor *v) +{ + return container_of(v, StringOutputVisitor, visitor); +} + static void string_output_set(StringOutputVisitor *sov, char *string) { if (sov->string) { @@ -120,7 +125,7 @@ static void format_string(StringOutputVisitor *sov, Range *r, bool next, static void print_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); GList *l; switch (sov->list_mode) { @@ -196,7 +201,7 @@ static void print_type_int(Visitor *v, int64_t *obj, const char *name, static void print_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' }; uint64_t div, val; char *out; @@ -227,14 +232,14 @@ static void print_type_size(Visitor *v, uint64_t *obj, const char *name, static void print_type_bool(Visitor *v, bool *obj, const char *name, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); string_output_set(sov, g_strdup(*obj ? "true" : "false")); } static void print_type_str(Visitor *v, char **obj, const char *name, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); char *out; if (sov->human) { @@ -248,14 +253,14 @@ static void print_type_str(Visitor *v, char **obj, const char *name, static void print_type_number(Visitor *v, double *obj, const char *name, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); string_output_set(sov, g_strdup_printf("%f", *obj)); } static void start_list(Visitor *v, const char *name, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); /* we can't traverse a list in a list */ assert(sov->list_mode == LM_NONE); @@ -266,7 +271,7 @@ start_list(Visitor *v, const char *name, Error **errp) static GenericList * next_list(Visitor *v, GenericList **list, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); GenericList *ret = NULL; if (*list) { if (sov->head) { @@ -293,7 +298,7 @@ next_list(Visitor *v, GenericList **list, Error **errp) static void end_list(Visitor *v, Error **errp) { - StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); + StringOutputVisitor *sov = to_sov(v); assert(sov->list_mode == LM_STARTED || sov->list_mode == LM_END || -- cgit v1.1 From 4c40314a35816de635e7170eaacdc0c35be83a8a Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 29 Jan 2016 06:48:49 -0700 Subject: qapi: Prefer type_int64 over type_int in visitors The qapi builtin type 'int' is basically shorthand for the type 'int64'. In fact, since no visitor was providing the optional type_int64() callback, visit_type_int64() was just always falling back to type_int(), cementing the equivalence between the types. However, some visitors are providing a type_uint64() callback. For purposes of code consistency, it is nicer if all visitors use the paired type_int64/type_uint64 names rather than the mismatched type_int/type_uint64. So this patch just renames the signed int callbacks in place, dropping the type_int() callback as redundant, and a later patch will focus on the unsigned int callbacks. Add some FIXMEs to questionable reuse of errp in code touched by the rename, while at it (the reuse works as long as the callbacks don't modify value when setting an error, but it's not a good example to set) - a later patch will then fix those. No change in functionality here, although further cleanups are in the pipeline. Signed-off-by: Eric Blake Message-Id: <1454075341-13658-14-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster --- qapi/string-output-visitor.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'qapi/string-output-visitor.c') diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index b0313cb..cf8dfc8 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -122,8 +122,8 @@ static void format_string(StringOutputVisitor *sov, Range *r, bool next, } } -static void print_type_int(Visitor *v, int64_t *obj, const char *name, - Error **errp) +static void print_type_int64(Visitor *v, int64_t *obj, const char *name, + Error **errp) { StringOutputVisitor *sov = to_sov(v); GList *l; @@ -346,7 +346,7 @@ StringOutputVisitor *string_output_visitor_new(bool human) v->string = g_string_new(NULL); v->human = human; v->visitor.type_enum = output_type_enum; - v->visitor.type_int = print_type_int; + v->visitor.type_int64 = print_type_int64; v->visitor.type_size = print_type_size; v->visitor.type_bool = print_type_bool; v->visitor.type_str = print_type_str; -- cgit v1.1 From f755dea79dc81b0d6a8f6414e0672e165e28d8ba Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 29 Jan 2016 06:48:50 -0700 Subject: qapi: Make all visitors supply uint64 callbacks Our qapi visitor contract supports multiple integer visitors, but left the type_uint64 visitor as optional (falling back on type_int64); which in turn can lead to awkward behavior with numbers larger than INT64_MAX (the user has to be aware of twos complement, and deal with negatives). This patch does not address the disparity in handling large values as negatives. It merely moves the fallback from uint64 to int64 from the visitor core to the visitors, where the issue can actually be fixed, by implementing the missing type_uint64() callbacks on top of the respective type_int64() callbacks, and with a FIXME comment explaining why that's wrong. With that done, we now have a type_uint64() callback in every driver, so we can make it mandatory from the core. And although the type_int64() callback can cover the entire valid range of type_uint{8,16,32} on valid user input, using type_uint64() to avoid mixed signedness makes more sense. Signed-off-by: Eric Blake Message-Id: <1454075341-13658-15-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster --- qapi/string-output-visitor.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'qapi/string-output-visitor.c') diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index cf8dfc8..8400c8b 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -198,6 +198,14 @@ static void print_type_int64(Visitor *v, int64_t *obj, const char *name, } } +static void print_type_uint64(Visitor *v, uint64_t *obj, const char *name, + Error **errp) +{ + /* FIXME: print_type_int64 mishandles values over INT64_MAX */ + int64_t i = *obj; + print_type_int64(v, &i, name, errp); +} + static void print_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp) { @@ -347,6 +355,7 @@ StringOutputVisitor *string_output_visitor_new(bool human) v->human = human; v->visitor.type_enum = output_type_enum; v->visitor.type_int64 = print_type_int64; + v->visitor.type_uint64 = print_type_uint64; v->visitor.type_size = print_type_size; v->visitor.type_bool = print_type_bool; v->visitor.type_str = print_type_str; -- cgit v1.1 From 0b2a0d6bb2446060944061e53e87d0c7addede79 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 29 Jan 2016 06:48:56 -0700 Subject: qapi: Swap 'name' in visit_* callbacks to match public API MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Signed-off-by: Eric Blake Reviewed-by: Marc-André Lureau Message-Id: <1454075341-13658-21-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster --- qapi/string-output-visitor.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'qapi/string-output-visitor.c') diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index 8400c8b..3ce6a3b 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -122,7 +122,7 @@ static void format_string(StringOutputVisitor *sov, Range *r, bool next, } } -static void print_type_int64(Visitor *v, int64_t *obj, const char *name, +static void print_type_int64(Visitor *v, const char *name, int64_t *obj, Error **errp) { StringOutputVisitor *sov = to_sov(v); @@ -198,16 +198,16 @@ static void print_type_int64(Visitor *v, int64_t *obj, const char *name, } } -static void print_type_uint64(Visitor *v, uint64_t *obj, const char *name, +static void print_type_uint64(Visitor *v, const char *name, uint64_t *obj, Error **errp) { /* FIXME: print_type_int64 mishandles values over INT64_MAX */ int64_t i = *obj; - print_type_int64(v, &i, name, errp); + print_type_int64(v, name, &i, errp); } -static void print_type_size(Visitor *v, uint64_t *obj, const char *name, - Error **errp) +static void print_type_size(Visitor *v, const char *name, uint64_t *obj, + Error **errp) { StringOutputVisitor *sov = to_sov(v); static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' }; @@ -237,14 +237,14 @@ static void print_type_size(Visitor *v, uint64_t *obj, const char *name, string_output_set(sov, out); } -static void print_type_bool(Visitor *v, bool *obj, const char *name, +static void print_type_bool(Visitor *v, const char *name, bool *obj, Error **errp) { StringOutputVisitor *sov = to_sov(v); string_output_set(sov, g_strdup(*obj ? "true" : "false")); } -static void print_type_str(Visitor *v, char **obj, const char *name, +static void print_type_str(Visitor *v, const char *name, char **obj, Error **errp) { StringOutputVisitor *sov = to_sov(v); @@ -258,7 +258,7 @@ static void print_type_str(Visitor *v, char **obj, const char *name, string_output_set(sov, out); } -static void print_type_number(Visitor *v, double *obj, const char *name, +static void print_type_number(Visitor *v, const char *name, double *obj, Error **errp) { StringOutputVisitor *sov = to_sov(v); -- cgit v1.1 From 08f9541dec51700abef0c37994213164ca4e4fc9 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 29 Jan 2016 06:48:59 -0700 Subject: qapi: Drop unused error argument for list and implicit struct No backend was setting an error when ending the visit of a list or implicit struct, or when moving to the next list node. Make the callers a bit easier to follow by making this a part of the contract, and removing the errp argument - callers can then unconditionally end an object as part of cleanup without having to think about whether a second error is dominated by a first, because there is no second error. A later patch will then tackle the larger task of splitting visit_end_struct(), which can indeed set an error. Signed-off-by: Eric Blake Message-Id: <1454075341-13658-24-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster --- qapi/string-output-visitor.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'qapi/string-output-visitor.c') diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index 3ce6a3b..b980bd3 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -1,7 +1,7 @@ /* * String printing Visitor * - * Copyright Red Hat, Inc. 2012 + * Copyright Red Hat, Inc. 2012-2016 * * Author: Paolo Bonzini * @@ -276,8 +276,7 @@ start_list(Visitor *v, const char *name, Error **errp) sov->head = true; } -static GenericList * -next_list(Visitor *v, GenericList **list, Error **errp) +static GenericList *next_list(Visitor *v, GenericList **list) { StringOutputVisitor *sov = to_sov(v); GenericList *ret = NULL; @@ -303,8 +302,7 @@ next_list(Visitor *v, GenericList **list, Error **errp) return ret; } -static void -end_list(Visitor *v, Error **errp) +static void end_list(Visitor *v) { StringOutputVisitor *sov = to_sov(v); -- cgit v1.1