From 668f62ec621e4e2919fb7d4caa5d805764c5852d Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 7 Jul 2020 18:06:02 +0200 Subject: error: Eliminate error_propagate() with Coccinelle, part 1 When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. Convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... return ... } to if (!foo(..., errp)) { ... ... return ... } where nothing else needs @err. Coccinelle script: @rule1 forall@ identifier fun, err, errp, lbl; expression list args, args2; binary operator op; constant c1, c2; symbol false; @@ if ( ( - fun(args, &err, args2) + fun(args, errp, args2) | - !fun(args, &err, args2) + !fun(args, errp, args2) | - fun(args, &err, args2) op c1 + fun(args, errp, args2) op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; ) } @rule2 forall@ identifier fun, err, errp, lbl; expression list args, args2; expression var; binary operator op; constant c1, c2; symbol false; @@ - var = fun(args, &err, args2); + var = fun(args, errp, args2); ... when != err if ( ( var | !var | var op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; | return var; ) } @depends on rule1 || rule2@ identifier err; @@ - Error *err = NULL; ... when != err Not exactly elegant, I'm afraid. The "when != lbl:" is necessary to avoid transforming if (fun(args, &err)) { goto out } ... out: error_propagate(errp, err); even though other paths to label out still need the error_propagate(). For an actual example, see sclp_realize(). Without the "when strict", Coccinelle transforms vfio_msix_setup(), incorrectly. I don't know what exactly "when strict" does, only that it helps here. The match of return is narrower than what I want, but I can't figure out how to express "return where the operand doesn't use @err". For an example where it's too narrow, see vfio_intx_enable(). Silently fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Converted manually. Line breaks tidied up manually. One nested declaration of @local_err deleted manually. Preexisting unwanted blank line dropped in hw/riscv/sifive_e.c. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Message-Id: <20200707160613.848843-35-armbru@redhat.com> --- qom/object.c | 32 ++++++++------------------------ 1 file changed, 8 insertions(+), 24 deletions(-) (limited to 'qom') diff --git a/qom/object.c b/qom/object.c index 07618816a7..08b2cad445 100644 --- a/qom/object.c +++ b/qom/object.c @@ -800,15 +800,13 @@ bool object_set_propv(Object *obj, va_list vargs) { const char *propname; - Error *local_err = NULL; propname = va_arg(vargs, char *); while (propname != NULL) { const char *value = va_arg(vargs, char *); g_assert(value != NULL); - if (!object_property_parse(obj, propname, value, &local_err)) { - error_propagate(errp, local_err); + if (!object_property_parse(obj, propname, value, errp)) { return false; } propname = va_arg(vargs, char *); @@ -2115,10 +2113,8 @@ static void property_set_str(Object *obj, Visitor *v, const char *name, { StringProperty *prop = opaque; char *value; - Error *local_err = NULL; - if (!visit_type_str(v, name, &value, &local_err)) { - error_propagate(errp, local_err); + if (!visit_type_str(v, name, &value, errp)) { return; } @@ -2195,10 +2191,8 @@ static void property_set_bool(Object *obj, Visitor *v, const char *name, { BoolProperty *prop = opaque; bool value; - Error *local_err = NULL; - if (!visit_type_bool(v, name, &value, &local_err)) { - error_propagate(errp, local_err); + if (!visit_type_bool(v, name, &value, errp)) { return; } @@ -2267,10 +2261,8 @@ static void property_set_enum(Object *obj, Visitor *v, const char *name, { EnumProperty *prop = opaque; int value; - Error *err = NULL; - if (!visit_type_enum(v, name, &value, prop->lookup, &err)) { - error_propagate(errp, err); + if (!visit_type_enum(v, name, &value, prop->lookup, errp)) { return; } prop->set(obj, value, errp); @@ -2419,10 +2411,8 @@ static void property_set_uint8_ptr(Object *obj, Visitor *v, const char *name, { uint8_t *field = opaque; uint8_t value; - Error *local_err = NULL; - if (!visit_type_uint8(v, name, &value, &local_err)) { - error_propagate(errp, local_err); + if (!visit_type_uint8(v, name, &value, errp)) { return; } @@ -2441,10 +2431,8 @@ static void property_set_uint16_ptr(Object *obj, Visitor *v, const char *name, { uint16_t *field = opaque; uint16_t value; - Error *local_err = NULL; - if (!visit_type_uint16(v, name, &value, &local_err)) { - error_propagate(errp, local_err); + if (!visit_type_uint16(v, name, &value, errp)) { return; } @@ -2463,10 +2451,8 @@ static void property_set_uint32_ptr(Object *obj, Visitor *v, const char *name, { uint32_t *field = opaque; uint32_t value; - Error *local_err = NULL; - if (!visit_type_uint32(v, name, &value, &local_err)) { - error_propagate(errp, local_err); + if (!visit_type_uint32(v, name, &value, errp)) { return; } @@ -2485,10 +2471,8 @@ static void property_set_uint64_ptr(Object *obj, Visitor *v, const char *name, { uint64_t *field = opaque; uint64_t value; - Error *local_err = NULL; - if (!visit_type_uint64(v, name, &value, &local_err)) { - error_propagate(errp, local_err); + if (!visit_type_uint64(v, name, &value, errp)) { return; } -- cgit v1.2.3