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> --- hw/smbios/smbios.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-) (limited to 'hw/smbios/smbios.c') diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c index 87afcf9142..f560826904 100644 --- a/hw/smbios/smbios.c +++ b/hw/smbios/smbios.c @@ -953,7 +953,6 @@ static void save_opt_list(size_t *ndest, const char ***dest, void smbios_entry_add(QemuOpts *opts, Error **errp) { - Error *err = NULL; const char *val; assert(!smbios_immutable); @@ -964,8 +963,7 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) int size; struct smbios_table *table; /* legacy mode only */ - if (!qemu_opts_validate(opts, qemu_smbios_file_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_file_opts, errp)) { return; } @@ -1050,8 +1048,7 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) switch (type) { case 0: - if (!qemu_opts_validate(opts, qemu_smbios_type0_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type0_opts, errp)) { return; } save_opt(&type0.vendor, opts, "vendor"); @@ -1069,8 +1066,7 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) } return; case 1: - if (!qemu_opts_validate(opts, qemu_smbios_type1_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type1_opts, errp)) { return; } save_opt(&type1.manufacturer, opts, "manufacturer"); @@ -1090,8 +1086,7 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) } return; case 2: - if (!qemu_opts_validate(opts, qemu_smbios_type2_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type2_opts, errp)) { return; } save_opt(&type2.manufacturer, opts, "manufacturer"); @@ -1102,8 +1097,7 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) save_opt(&type2.location, opts, "location"); return; case 3: - if (!qemu_opts_validate(opts, qemu_smbios_type3_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type3_opts, errp)) { return; } save_opt(&type3.manufacturer, opts, "manufacturer"); @@ -1113,8 +1107,7 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) save_opt(&type3.sku, opts, "sku"); return; case 4: - if (!qemu_opts_validate(opts, qemu_smbios_type4_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type4_opts, errp)) { return; } save_opt(&type4.sock_pfx, opts, "sock_pfx"); @@ -1125,15 +1118,13 @@ void smbios_entry_add(QemuOpts *opts, Error **errp) save_opt(&type4.part, opts, "part"); return; case 11: - if (!qemu_opts_validate(opts, qemu_smbios_type11_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type11_opts, errp)) { return; } save_opt_list(&type11.nvalues, &type11.values, opts, "value"); return; case 17: - if (!qemu_opts_validate(opts, qemu_smbios_type17_opts, &err)) { - error_propagate(errp, err); + if (!qemu_opts_validate(opts, qemu_smbios_type17_opts, errp)) { return; } save_opt(&type17.loc_pfx, opts, "loc_pfx"); -- cgit 1.4.1