Messages in this thread |  | | Date | Sat, 24 Dec 2022 13:28:04 +0100 (CET) | From | Julia Lawall <> | Subject | Re: coccinelle: How to remove a return at the end of a void function? |
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On Sat, 24 Dec 2022, Uwe Kleine-König wrote:
> Hello, > > I work on a patch set that eventually makes the function > rtsx_usb_sdmmc_drv_remove() return void: > > A simplified spatch looks as follows: > > -------->8-------- > virtual patch > > @p1@ > identifier pdev; > @@ > -int > +void > rtsx_usb_sdmmc_drv_remove(struct platform_device *pdev) { > <... > -return 0; > +return; > ...> > } > -------->8-------- > > This results in: > > -------->8-------- > diff -u -p a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c > --- a/drivers/mmc/host/rtsx_usb_sdmmc.c > +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c > @@ -1379,13 +1379,13 @@ static int rtsx_usb_sdmmc_drv_probe(stru > return 0; > } > > -static int rtsx_usb_sdmmc_drv_remove(struct platform_device *pdev) > +static void rtsx_usb_sdmmc_drv_remove(struct platform_device *pdev) > { > struct rtsx_usb_sdmmc *host = platform_get_drvdata(pdev); > struct mmc_host *mmc; > > if (!host) > - return 0; > + return; > > mmc = host->mmc; > host->host_removal = true; > @@ -1416,7 +1416,7 @@ static int rtsx_usb_sdmmc_drv_remove(str > dev_dbg(&(pdev->dev), > ": Realtek USB SD/MMC module has been removed\n"); > > - return 0; > + return; > } > > #ifdef CONFIG_PM > -------->8-------- > > which is as intended. Now I want to remove the useless "return;" at the > end of the function, however adding > > -------->8-------- > @p2 depends on p1@ > identifier pdev; > @@ > void rtsx_usb_sdmmc_drv_remove(struct platform_device *pdev) { > ... > -return; > } > -------->8-------- > > to the spatch doesn't (only) do the intended:
The problem is that Coccinelle is following the control-flow through the function, and all of the returns are at the end of a control.flow path. The simple, hacky solution is to change the return;s into some function call Return();, then do like the above for Return(); and then change the Return();s back to return;s
julia
> > -------->8-------- > diff -u -p a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c > --- a/drivers/mmc/host/rtsx_usb_sdmmc.c > +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c > @@ -1379,13 +1379,13 @@ static int rtsx_usb_sdmmc_drv_probe(stru > return 0; > } > > -static int rtsx_usb_sdmmc_drv_remove(struct platform_device *pdev) > +static void rtsx_usb_sdmmc_drv_remove(struct platform_device *pdev) > { > struct rtsx_usb_sdmmc *host = platform_get_drvdata(pdev); > struct mmc_host *mmc; > > if (!host) > - return 0; > + {} > > mmc = host->mmc; > host->host_removal = true; > @@ -1415,8 +1415,6 @@ static int rtsx_usb_sdmmc_drv_remove(str > > dev_dbg(&(pdev->dev), > ": Realtek USB SD/MMC module has been removed\n"); > - > - return 0; > } > > #ifdef CONFIG_PM > -------->8-------- > > It's obvious to me, why coccinelle also removes the first return, but > it's not obvious to me, how to prevent this and only drop the 2nd one. > > Do you have a hint for me? > > Thanks in advance and happy holidays, > Uwe > > > -- > Pengutronix e.K. | Uwe Kleine-König | > Industrial Linux Solutions | https://www.pengutronix.de/ | >
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