Re: [Cocci] [RFC] treewide: cleanup unreachable breaks
On Sat, 17 Oct 2020, Joe Perches wrote: > On Sat, 2020-10-17 at 09:09 -0700, t...@redhat.com wrote: > > From: Tom Rix > > > > This is a upcoming change to clean up a new warning treewide. > > I am wondering if the change could be one mega patch (see below) or > > normal patch per file about 100 patches or somewhere half way by collecting > > early acks. > > > > clang has a number of useful, new warnings see > > https://clang.llvm.org/docs/DiagnosticsReference.html > > > > This change cleans up -Wunreachable-code-break > > https://clang.llvm.org/docs/DiagnosticsReference.html#wunreachable-code-break > > for 266 of 485 warnings in this week's linux-next, allyesconfig on x86_64. > > Early acks/individual patches by subsystem would be good. > Better still would be an automated cocci script. Coccinelle is not especially good at this, because it is based on control flow, and a return or goto diverts the control flow away from the break. A hack to solve the problem is to put an if around the return or goto, but that gives the break a meaningless file name and line number. I collected the following list, but it only has 439 results, so fewer than clang. But maybe there are some files that are not considered by clang in the x86 allyesconfig configuration. Probably checkpatch is the best solution here, since it is not configuration sensitive and doesn't care about control flow. julia drivers/scsi/mvumi.c: function mvumi_cfg_hw_reg line 114 drivers/watchdog/geodewdt.c: function geodewdt_ioctl line 18 drivers/media/usb/b2c2/flexcop-usb.c: function flexcop_usb_init line 21 drivers/media/usb/b2c2/flexcop-usb.c: function flexcop_usb_memory_req line 20 drivers/tty/nozomi.c: function write_mem32 line 17 drivers/tty/nozomi.c: function write_mem32 line 25 drivers/tty/nozomi.c: function read_mem32 line 17 drivers/tty/nozomi.c: function read_mem32 line 21 sound/soc/codecs/wl1273.c: function wl1273_startup line 27 drivers/iio/adc/meson_saradc.c: function meson_sar_adc_iio_info_read_raw line 12 drivers/iio/adc/meson_saradc.c: function meson_sar_adc_iio_info_read_raw line 19 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c: function map_transmitter_id_to_phy_instance line 6 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c: function map_transmitter_id_to_phy_instance line 9 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c: function map_transmitter_id_to_phy_instance line 12 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c: function map_transmitter_id_to_phy_instance line 15 drivers/media/tuners/mt2063.c: function mt2063_init line 81 drivers/nfc/st21nfca/core.c: function st21nfca_hci_im_transceive line 46 arch/sh/boards/mach-landisk/gio.c: function gio_ioctl line 53 drivers/gpu/drm/mgag200/mgag200_mode.c: function mgag200_crtc_set_plls line 11 drivers/gpu/drm/mgag200/mgag200_mode.c: function mgag200_crtc_set_plls line 15 drivers/gpu/drm/mgag200/mgag200_mode.c: function mgag200_crtc_set_plls line 18 drivers/gpu/drm/mgag200/mgag200_mode.c: function mgag200_crtc_set_plls line 22 drivers/gpu/drm/mgag200/mgag200_mode.c: function mgag200_crtc_set_plls line 25 drivers/media/dvb-frontends/cx24117.c: function cx24117_attach line 16 drivers/block/xen-blkback/blkback.c: function dispatch_rw_block_io line 48 drivers/platform/x86/sony-laptop.c: function __sony_nc_gfx_switch_status_get line 16 drivers/platform/x86/sony-laptop.c: function __sony_nc_gfx_switch_status_get line 22 drivers/platform/x86/sony-laptop.c: function __sony_nc_gfx_switch_status_get line 31 drivers/char/mwave/mwavedd.c: function mwave_ioctl line 288 drivers/scsi/be2iscsi/be_mgmt.c: function beiscsi_adap_family_disp line 15 drivers/scsi/be2iscsi/be_mgmt.c: function beiscsi_adap_family_disp line 19 drivers/scsi/be2iscsi/be_mgmt.c: function beiscsi_adap_family_disp line 22 drivers/scsi/be2iscsi/be_mgmt.c: function beiscsi_adap_family_disp line 27 drivers/iio/imu/bmi160/bmi160_core.c: function bmi160_write_raw line 11 drivers/block/z2ram.c: function z2_open line 138 drivers/net/wireless/realtek/rtlwifi/rtl8723ae/hw.c: function _rtl8723e_set_media_status line 38 samples/hidraw/hid-example.c: function bus_str line 6 samples/hidraw/hid-example.c: function bus_str line 9 samples/hidraw/hid-example.c: function bus_str line 12 samples/hidraw/hid-example.c: function bus_str line 15 samples/hidraw/hid-example.c: function bus_str line 18 drivers/scsi/ipr.c: function ipr_pci_error_detected line 10 drivers/gpio/gpio-bd70528.c: function bd70528_gpio_set_config line 11 drivers/gpio/gpio-bd70528.c: function bd70528_gpio_set_config line 17 drivers/gpio/gpio-bd70528.c: function bd70528_gpio_set_config line 21 drivers/pinctrl/pinctrl-rockchip.c: function rockchip_pinconf_get line 71 drivers/pinctrl/pinctrl-rockchip.c: function rockchip_pinconf_set line 74 drivers/gpu/drm/amd/display/include/signal_types.h: function dc_is_dvi_signal line 6 security/keys/trusted-keys/trusted_tpm1.c: function datablob_parse line 63 arch/x86/math-emu/fpu_trig.c: function
Re: [Cocci] [RFC] treewide: cleanup unreachable breaks
On Sat, 2020-10-17 at 20:21 +0200, Julia Lawall wrote: > On Sat, 17 Oct 2020, Joe Perches wrote: > > On Sat, 2020-10-17 at 09:09 -0700, t...@redhat.com wrote: > > > From: Tom Rix > > > > > > This is a upcoming change to clean up a new warning treewide. > > > I am wondering if the change could be one mega patch (see below) or > > > normal patch per file about 100 patches or somewhere half way by > > > collecting > > > early acks. > > > > > > clang has a number of useful, new warnings see > > > https://clang.llvm.org/docs/DiagnosticsReference.html > > > > > > This change cleans up -Wunreachable-code-break > > > https://clang.llvm.org/docs/DiagnosticsReference.html#wunreachable-code-break > > > for 266 of 485 warnings in this week's linux-next, allyesconfig on x86_64. > > > > Early acks/individual patches by subsystem would be good. > > Better still would be an automated cocci script. > > Coccinelle is not especially good at this, because it is based on control > flow, and a return or goto diverts the control flow away from the break. > A hack to solve the problem is to put an if around the return or goto, but > that gives the break a meaningless file name and line number. I collected > the following list, but it only has 439 results, so fewer than clang. But > maybe there are some files that are not considered by clang in the x86 > allyesconfig configuration. > > Probably checkpatch is the best solution here, since it is not > configuration sensitive and doesn't care about control flow. Likely the clang compiler is the best option here. It might be useful to add -Wunreachable-code-break to W=1 or just always enable it if it isn't already enabled. diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 95e4cdb94fe9..3819787579d5 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -32,6 +32,7 @@ KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable) KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable) KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned) KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) +KBUILD_CFLAGS += $(call cc-option, -Wunreachable-code-break) # The following turn off the warnings enabled by -Wextra KBUILD_CFLAGS += -Wno-missing-field-initializers KBUILD_CFLAGS += -Wno-sign-compare (and thank you Tom for pushing this forward) checkpatch can't find instances like: case FOO: if (foo) return 1; else return 2; break; As it doesn't track flow and relies on the number of tabs to be the same for any goto/return and break; checkpatch will warn on: case FOO: ... goto bar; break; ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
