| Message ID | 20170207015047.4ffc3xzrqsuuzo54@macpro.local (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/06/2017 05:50 PM, Luc Van Oostenryck wrote: > On Mon, Feb 06, 2017 at 05:08:17PM -0800, Stephen Boyd wrote: >> On 02/06/2017 05:01 PM, Stephen Boyd wrote: >>> When I compile files with sparse, I get these sorts of warnings: >>> >>> arch/arm64/include/asm/lse.h:14:28: warning: Unknown escape 'l' >>> arch/arm64/include/asm/lse.h:14:37: warning: Unknown escape 'l' >>> arch/arm64/include/asm/alternative.h:172:28: warning: Unknown escape 'o' >>> >>> This is because sparse is trying to tokenize these files and sees >>> a line like this: >>> >>> alternative_insn "\llsc", "\lse", ARM64_HAS_LSE_ATOMICS >>> >>> It gets past alternative_insn part and then sees the start of a >>> string with the double quote character. So sparse starts to parse >>> the string (eat_string() in the sparse code) but the string has >>> an escape character '\' in it. Sparse sees the escape character, >>> so it checks to see if it's an escape sequence, but '\l' isn't. >>> This causes sparse to spit out this warning of an unknown escape >>> sequence 'l'. >>> >>> In reality, sparse isn't going to use these macros anyway because >>> this whole thing is inside an __ASSEMBLER__ ifdef. > Yes, annoying. Conversion of escaped characters is supposed to be > done just after preprocessing. It's definitively a bug. Ok. Thanks for the fixes to sparse. My hack patch can be safely ignored.
On Tue, Feb 7, 2017 at 9:11 PM, Stephen Boyd <sboyd@codeaurora.org> wrote: > On 02/06/2017 05:50 PM, Luc Van Oostenryck wrote: >> On Mon, Feb 06, 2017 at 05:08:17PM -0800, Stephen Boyd wrote: >>> On 02/06/2017 05:01 PM, Stephen Boyd wrote: >>>> When I compile files with sparse, I get these sorts of warnings: >>>> >>>> arch/arm64/include/asm/lse.h:14:28: warning: Unknown escape 'l' >>>> arch/arm64/include/asm/lse.h:14:37: warning: Unknown escape 'l' >>>> arch/arm64/include/asm/alternative.h:172:28: warning: Unknown escape 'o' >>>> >>>> This is because sparse is trying to tokenize these files and sees >>>> a line like this: >>>> >>>> alternative_insn "\llsc", "\lse", ARM64_HAS_LSE_ATOMICS >>>> >>>> It gets past alternative_insn part and then sees the start of a >>>> string with the double quote character. So sparse starts to parse >>>> the string (eat_string() in the sparse code) but the string has >>>> an escape character '\' in it. Sparse sees the escape character, >>>> so it checks to see if it's an escape sequence, but '\l' isn't. >>>> This causes sparse to spit out this warning of an unknown escape >>>> sequence 'l'. >>>> >>>> In reality, sparse isn't going to use these macros anyway because >>>> this whole thing is inside an __ASSEMBLER__ ifdef. >> Yes, annoying. Conversion of escaped characters is supposed to be >> done just after preprocessing. It's definitively a bug. > > Ok. Thanks for the fixes to sparse. My hack patch can be safely ignored. Well, I don't know. Maybe it's still useful for everyone using the official version of sparse or an older one. Luc Van Oostenryck
diff --git a/validation/preprocessor/early-escape.c b/validation/preprocessor/early-escape.c new file mode 100644 index 000000000..c7beba5d8 --- /dev/null +++ b/validation/preprocessor/early-escape.c @@ -0,0 +1,23 @@ +#if 0 +"\l" +#endif + +/* + * check-description: + * Following the C standard, escape conversion must be + * done in phase 5, just after preprocessing and just + * before string concatenation. So we're not supposed + * to receive a diagnostic for an unknown escape char + * for a token which is excluded by the preprocessor. + * check-name: early-escape + * check-command: sparse -E $file + * check-known-to-fail + * + * check-output-start + + + * check-output-end + * + * check-error-start + * check-error-end + */