From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Fri, 15 May 2015 09:13:59 +0200 Subject: [U-Boot] [PATCH v1 1/4] Kconfig: Enable usage of escape char '\' in string values In-Reply-To: References: <1431000847-22183-1-git-send-email-sr@denx.de> <1431000847-22183-2-git-send-email-sr@denx.de> <5550613D.9050009@denx.de> <5550AE5E.5020204@roese.nl> Message-ID: <55559CB7.1050807@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Masahiro, On 13.05.2015 03:34, Masahiro Yamada wrote: > Hi, Simon, Stefan, > > > 2015-05-12 7:41 GMT+09:00 Simon Glass : >> Hi Stefan, >> >> On 11 May 2015 at 07:27, Stefan Roese wrote: >>> Hi Simon, Hi Masahiro, >>> >>> >>> On 11.05.2015 09:58, Stefan Roese wrote: >>>> >>>> On 10.05.2015 16:48, Simon Glass wrote: >>>>> >>>>> On 7 May 2015 at 06:13, Stefan Roese wrote: >>>>>> >>>>>> I might have missed something, but I failed to use the escape char '\' >>>>>> in strings. To pass a printf format string like "foo %d bar\n" via >>>>>> Kconfig to the code. >>>>>> >>>>>> Right now its not possible to use the escape character '\' in Kconfig >>>>>> string values correctly to e.g. set this string value "test output\n". >>>>>> The '\n' will be converted to 'n'. >>>>>> >>>>>> The current implementation removes some of the '\' chars from the input >>>>>> string in conf_set_sym_val(). Examples: >>>>>> >>>>>> '\' -> '' >>>>>> '\\' -> '\' >>>>>> '\\\' -> '\' >>>>>> '\\\\' -> '\\' >>>>>> ... >>>>>> >>>>>> And then doubles the backslash chars in the output string in >>>>>> sym_escape_string_value(). Example: >>>>>> >>>>>> '\' -> '' -> '' >>>>>> '\\' -> '\' -> '\\' >>>>>> '\\\' -> '\' -> '\\' >>>>>> '\\\\' -> '\\' -> '\\\\' >>>>>> ... >>>>>> >>>>>> As you see in these examples, its impossible to generate a single '\' >>>>>> charater in the output string as its needed for something like '\n'. >>>>>> >>>>>> This patch now changes this behavior to not drop some backslashes in >>>>>> conf_set_sym_val() and to not add new backslashes in the resulting >>>>>> output string. Removing the function sym_escape_string_value() >>>>>> completely as its not needed anymore. >>>>>> >>>>>> Signed-off-by: Stefan Roese >>>>>> Cc: Masahiro Yamada >>>>>> Cc: Simon Glass >>>>>> --- >>>>>> >>>>>> scripts/kconfig/confdata.c | 20 +++++++++----------- >>>>>> scripts/kconfig/symbol.c | 43 >>>>>> ------------------------------------------- >>>>>> 2 files changed, 9 insertions(+), 54 deletions(-) >>>>> >>>>> >>>>> This looks right to me. But I do see one problem - the default string >>>>> for CONFIG_AUTOBOOT_PROMPT appears as: >>>>> >>>>> "Autoboot in %d secondsn" >>>>> >>>>> so something is still removing the \ in the Kconfig default; >>>> >>>> >>>> Right. Thanks for spotting. I'll fix this in v3. >>> >>> >>> I could easily change the default string in the Kconfig file to "Autoboot in >>> %d seconds\\n". This works. But its a different syntax regarding using the >>> escape character backslash compared to editing the .config file or editing >>> the string in "make menuconfig etc...". So I hesitate to "fix" it this way. >>> >>> Unfortunately fixing this issue in the code is not that easy. At least not >>> for me. As the default values of the "string values" are set in the >>> conf_parse() function (in scripts/kconfig/zconf.y). And I really have >>> absolutely no experience with yacc / bison. Perhaps one of you guys has a >>> quick fix to make this default value of strings compatible again so that >>> this additional '\' is not needed in the Kconfig file? >> >> Well I am familiar with those tools but I think Masahiro probably >> knows a lot more here. > > > I am not so familiar with Bison, and I am getting a bit busy these days. > So, I cannot find time to take a close look. Sorry. > > If Simon (or someone else) could follow it up, that'd be nice. > > BTW, if you have already figured out that conf_parse() is the cause of > the problem, > you do not have to invoke Bison. > > Bison does not touch the C part. > conf_parse() is just copied verbatim from zconf.y to zconf.tab.c_shipped. > > You can modify conf_parse() exactly in the same way in both of them. Thanks. Did it and found that zconfparse() is responsible for this default value configuration / parsing. I must be missing something, but I fail to see where this function is really implemented: $ git grep zconfparse scripts/kconfig/lkc.h:int zconfparse(void); scripts/kconfig/zconf.tab.c_shipped:#define yyparse zconfparse scripts/kconfig/zconf.tab.c_shipped: zconfparse(); scripts/kconfig/zconf.y: zconfparse(); I'm inclined to just add this additional backslash to the default value in Kconfig. Thanks, Stefan