mirror of https://gitee.com/openkylin/qemu.git
![]() 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 <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-35-armbru@redhat.com> |
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.. | ||
Makefile.objs | ||
audio.json | ||
authz.json | ||
block-core.json | ||
block.json | ||
char.json | ||
common.json | ||
control.json | ||
crypto.json | ||
dump.json | ||
error.json | ||
introspect.json | ||
job.json | ||
machine-target.json | ||
machine.json | ||
migration.json | ||
misc-target.json | ||
misc.json | ||
net.json | ||
opts-visitor.c | ||
pragma.json | ||
qapi-clone-visitor.c | ||
qapi-dealloc-visitor.c | ||
qapi-schema.json | ||
qapi-util.c | ||
qapi-visit-core.c | ||
qdev.json | ||
qmp-dispatch.c | ||
qmp-event.c | ||
qmp-registry.c | ||
qobject-input-visitor.c | ||
qobject-output-visitor.c | ||
qom.json | ||
rdma.json | ||
rocker.json | ||
run-state.json | ||
sockets.json | ||
string-input-visitor.c | ||
string-output-visitor.c | ||
tpm.json | ||
trace-events | ||
trace.json | ||
transaction.json | ||
ui.json |