qemu/target/ppc
Markus Armbruster 668f62ec62 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 <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
..
translate target/ppc: Use tcg_gen_gvec_rotlv 2020-06-02 08:42:37 -07:00
arch_dump.c target/ppc: Add helper_mfvscr 2019-02-18 11:00:44 +11:00
compat.c error: Eliminate error_propagate() with Coccinelle, part 1 2020-07-10 15:18:08 +02:00
cpu-models.c target/ppc: Add POWER10 DD1.0 model information 2019-12-17 10:39:48 +11:00
cpu-models.h target/ppc: Add POWER10 DD1.0 model information 2019-12-17 10:39:48 +11:00
cpu-param.h tcg: Split out target/arch/cpu-param.h 2019-06-10 07:03:34 -07:00
cpu-qom.h x86 and machine queue for 5.0 soft freeze 2020-03-19 14:22:46 +00:00
cpu.c target/ppc: support for 32-bit carry and overflow 2017-03-01 11:23:39 +11:00
cpu.h target/ppc: Restrict PPCVirtualHypervisorClass to system-mode 2020-06-12 11:12:45 -04:00
dfp_helper.c target/ppc: remove unnecessary if() around calls to set_dfp{64,128}() in DFP macros 2019-10-04 19:08:21 +10:00
excp_helper.c ppc/spapr: Add hotremovable flag on DIMM LMBs on drmem_v2 2020-05-27 15:29:36 +10:00
fpu_helper.c target/ppc: Fix typo in comments 2020-02-21 09:15:04 +11:00
gdbstub.c gdbstub: Introduce gdb_get_float64() to get 64-bit float registers 2020-05-06 09:29:26 +01:00
helper_regs.h ppc: Ignore the CPU_INTERRUPT_EXITTB interrupt with KVM 2019-12-17 10:39:48 +11:00
helper.h target/ppc: Use tcg_gen_gvec_rotlv 2020-06-02 08:42:37 -07:00
int_helper.c target/ppc: Use tcg_gen_gvec_rotlv 2020-06-02 08:42:37 -07:00
internal.h ppc: Add support for 'mffscrn','mffscrni' instructions 2019-10-04 10:25:23 +10:00
kvm_ppc.h target/ppc: Restrict PPCVirtualHypervisorClass to system-mode 2020-06-12 11:12:45 -04:00
kvm-stub.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
kvm.c target/ppc: Fix wrong interpretation of the disposition flag. 2020-04-17 10:38:29 +10:00
machine.c Include hw/boards.h a bit less 2019-08-16 13:31:53 +02:00
Makefile.objs build: remove CONFIG_LIBDECNUMBER 2017-10-16 18:03:52 +02:00
mem_helper.c target/ppc: Use probe_write for DCBZ 2020-02-03 11:33:11 +11:00
mfrom_table_gen.c target/ppc: Style fixes for mfrom_table.inc.c & mfrom_table_gen.c 2019-04-26 10:42:38 +10:00
mfrom_table.inc.c target/ppc: Style fixes for mfrom_table.inc.c & mfrom_table_gen.c 2019-04-26 10:42:38 +10:00
misc_helper.c target/ppc: add support for Hypervisor Facility Unavailable Exception 2020-02-02 14:07:57 +11:00
mmu_helper.c target: Remove unnecessary CPU() cast 2020-05-15 07:08:14 +02:00
mmu-book3s-v3.c target/ppc: Support for POWER9 native hash 2019-02-26 09:21:25 +11:00
mmu-book3s-v3.h Clean up header guards that don't match their file name 2019-05-13 08:58:55 +02:00
mmu-hash32.c ppc/hash32: Rework R and C bit updates 2019-04-26 11:37:57 +10:00
mmu-hash32.h target/ppc: Manage external HPT via virtual hypervisor 2017-03-01 11:23:39 +11:00
mmu-hash64.c target/ppc: Fix ISA v3.0 (POWER9) slbia implementation 2020-03-24 11:56:14 +11:00
mmu-hash64.h ppc/hash64: Rework R and C bit updates 2019-04-26 11:37:57 +10:00
mmu-radix64.c target/ppc: Fix argument to ppc_radix64_partition_scoped_xlate() again 2020-05-27 15:29:36 +10:00
mmu-radix64.h target/ppc: Pass const pointer to ppc_radix64_get_prot_amr() 2020-05-27 15:29:36 +10:00
monitor.c hmp: Move hmp.h to include/monitor/ 2019-07-02 07:19:45 +02:00
timebase_helper.c hw/ppc: Take QEMU lock when calling ppc_dcr_read/write() 2020-03-24 11:56:37 +11:00
trace-events target/ppc: Handle NMI guest exit 2020-02-03 11:33:10 +11:00
translate_init.inc.c qom: Put name parameter before value / visitor parameter 2020-07-10 15:18:08 +02:00
translate.c target/ppc: Add support for scv and rfscv instructions 2020-05-27 15:29:24 +10:00
user_only_helper.c target/ppc: Convert to CPUClass::tlb_fill 2019-05-10 11:12:50 -07:00