| Message ID | 20131007114501.1519f7dd@endymion.delvare (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Monday, October 07, 2013 11:45:01 AM Jean Delvare wrote: > When ACPI debugging is disabled, I see warnings like this one: > > drivers/i2c/busses/i2c-scmi.c: In function "acpi_smbus_cmi_add_cap": > drivers/i2c/busses/i2c-scmi.c:328:39: warning: suggest braces around empty body in an "else" statement [-Wempty-body] > drivers/i2c/busses/i2c-scmi.c:338:12: warning: suggest braces around empty body in an "else" statement [-Wempty-body] > > It is caused by ACPI_DEBUG_PRINT (or other similar macros) to resolve > to nothing. Make them resolve to the classic "do {} while (0)" construct > instead when the compiler likes that, to silent all such warnings. The rule is that ACPICA patches need to go via upstream ACPICA, so I CCed the ACPICA maintainers. Thanks! > Signed-off-by: Jean Delvare <jdelvare@suse.de> > Cc: Len Brown <lenb@kernel.org> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > --- > include/acpi/acoutput.h | 40 +++++++++++++++++++++++++--------------- > 1 file changed, 25 insertions(+), 15 deletions(-) > > --- linux-3.12-rc4.orig/include/acpi/acoutput.h 2013-09-24 00:41:09.000000000 +0200 > +++ linux-3.12-rc4/include/acpi/acoutput.h 2013-10-07 11:23:57.928436503 +0200 > @@ -427,22 +427,32 @@ > /* > * This is the non-debug case -- make everything go away, > * leaving no executable debug code! > + * > + * Note: the ACPI_DO_WHILE0 macro is used to prevent some compilers from > + * complaining about these constructs. On other compilers the do...while > + * adds some extra code, so this feature is optional. > */ > -#define ACPI_DEBUG_PRINT(pl) > -#define ACPI_DEBUG_PRINT_RAW(pl) > -#define ACPI_DEBUG_EXEC(a) > -#define ACPI_DEBUG_ONLY_MEMBERS(a) > -#define ACPI_FUNCTION_NAME(a) > -#define ACPI_FUNCTION_TRACE(a) > -#define ACPI_FUNCTION_TRACE_PTR(a, b) > -#define ACPI_FUNCTION_TRACE_U32(a, b) > -#define ACPI_FUNCTION_TRACE_STR(a, b) > -#define ACPI_FUNCTION_ENTRY() > -#define ACPI_DUMP_STACK_ENTRY(a) > -#define ACPI_DUMP_OPERANDS(a, b, c) > -#define ACPI_DUMP_ENTRY(a, b) > -#define ACPI_DUMP_PATHNAME(a, b, c, d) > -#define ACPI_DUMP_BUFFER(a, b) > +#ifdef ACPI_USE_DO_WHILE_0 > +#define ACPI_DO_WHILE0 do {} while (0) > +#else > +#define ACPI_DO_WHILE0 > +#endif > + > +#define ACPI_DEBUG_PRINT(pl) ACPI_DO_WHILE0 > +#define ACPI_DEBUG_PRINT_RAW(pl) ACPI_DO_WHILE0 > +#define ACPI_DEBUG_EXEC(a) ACPI_DO_WHILE0 > +#define ACPI_DEBUG_ONLY_MEMBERS(a) ACPI_DO_WHILE0 > +#define ACPI_FUNCTION_NAME(a) ACPI_DO_WHILE0 > +#define ACPI_FUNCTION_TRACE(a) ACPI_DO_WHILE0 > +#define ACPI_FUNCTION_TRACE_PTR(a, b) ACPI_DO_WHILE0 > +#define ACPI_FUNCTION_TRACE_U32(a, b) ACPI_DO_WHILE0 > +#define ACPI_FUNCTION_TRACE_STR(a, b) ACPI_DO_WHILE0 > +#define ACPI_FUNCTION_ENTRY() ACPI_DO_WHILE0 > +#define ACPI_DUMP_STACK_ENTRY(a) ACPI_DO_WHILE0 > +#define ACPI_DUMP_OPERANDS(a, b, c) ACPI_DO_WHILE0 > +#define ACPI_DUMP_ENTRY(a, b) ACPI_DO_WHILE0 > +#define ACPI_DUMP_PATHNAME(a, b, c, d) ACPI_DO_WHILE0 > +#define ACPI_DUMP_BUFFER(a, b) ACPI_DO_WHILE0 > #define ACPI_IS_DEBUG_ENABLED(level, component) 0 > > /* Return macros must have a return statement at the minimum */ > > >
Le Monday 07 October 2013 à 14:11 +0200, Rafael J. Wysocki a écrit : > On Monday, October 07, 2013 11:45:01 AM Jean Delvare wrote: > > When ACPI debugging is disabled, I see warnings like this one: > > > > drivers/i2c/busses/i2c-scmi.c: In function "acpi_smbus_cmi_add_cap": > > drivers/i2c/busses/i2c-scmi.c:328:39: warning: suggest braces around empty body in an "else" statement [-Wempty-body] > > drivers/i2c/busses/i2c-scmi.c:338:12: warning: suggest braces around empty body in an "else" statement [-Wempty-body] > > > > It is caused by ACPI_DEBUG_PRINT (or other similar macros) to resolve > > to nothing. Make them resolve to the classic "do {} while (0)" construct > > instead when the compiler likes that, to silent all such warnings. > > The rule is that ACPICA patches need to go via upstream ACPICA, so I CCed > the ACPICA maintainers. Thanks Rafael. Maybe MAINTAINERS should be adjusted accordingly. Contributors can't guess. Thanks,
On Monday, October 07, 2013 07:08:00 PM Jean Delvare wrote: > Le Monday 07 October 2013 à 14:11 +0200, Rafael J. Wysocki a écrit : > > On Monday, October 07, 2013 11:45:01 AM Jean Delvare wrote: > > > When ACPI debugging is disabled, I see warnings like this one: > > > > > > drivers/i2c/busses/i2c-scmi.c: In function "acpi_smbus_cmi_add_cap": > > > drivers/i2c/busses/i2c-scmi.c:328:39: warning: suggest braces around empty body in an "else" statement [-Wempty-body] > > > drivers/i2c/busses/i2c-scmi.c:338:12: warning: suggest braces around empty body in an "else" statement [-Wempty-body] > > > > > > It is caused by ACPI_DEBUG_PRINT (or other similar macros) to resolve > > > to nothing. Make them resolve to the classic "do {} while (0)" construct > > > instead when the compiler likes that, to silent all such warnings. > > > > The rule is that ACPICA patches need to go via upstream ACPICA, so I CCed > > the ACPICA maintainers. > > Thanks Rafael. Maybe MAINTAINERS should be adjusted accordingly. > Contributors can't guess. That actually is a good idea. I think we'll do that. Thanks!
--- linux-3.12-rc4.orig/include/acpi/acoutput.h 2013-09-24 00:41:09.000000000 +0200 +++ linux-3.12-rc4/include/acpi/acoutput.h 2013-10-07 11:23:57.928436503 +0200 @@ -427,22 +427,32 @@ /* * This is the non-debug case -- make everything go away, * leaving no executable debug code! + * + * Note: the ACPI_DO_WHILE0 macro is used to prevent some compilers from + * complaining about these constructs. On other compilers the do...while + * adds some extra code, so this feature is optional. */ -#define ACPI_DEBUG_PRINT(pl) -#define ACPI_DEBUG_PRINT_RAW(pl) -#define ACPI_DEBUG_EXEC(a) -#define ACPI_DEBUG_ONLY_MEMBERS(a) -#define ACPI_FUNCTION_NAME(a) -#define ACPI_FUNCTION_TRACE(a) -#define ACPI_FUNCTION_TRACE_PTR(a, b) -#define ACPI_FUNCTION_TRACE_U32(a, b) -#define ACPI_FUNCTION_TRACE_STR(a, b) -#define ACPI_FUNCTION_ENTRY() -#define ACPI_DUMP_STACK_ENTRY(a) -#define ACPI_DUMP_OPERANDS(a, b, c) -#define ACPI_DUMP_ENTRY(a, b) -#define ACPI_DUMP_PATHNAME(a, b, c, d) -#define ACPI_DUMP_BUFFER(a, b) +#ifdef ACPI_USE_DO_WHILE_0 +#define ACPI_DO_WHILE0 do {} while (0) +#else +#define ACPI_DO_WHILE0 +#endif + +#define ACPI_DEBUG_PRINT(pl) ACPI_DO_WHILE0 +#define ACPI_DEBUG_PRINT_RAW(pl) ACPI_DO_WHILE0 +#define ACPI_DEBUG_EXEC(a) ACPI_DO_WHILE0 +#define ACPI_DEBUG_ONLY_MEMBERS(a) ACPI_DO_WHILE0 +#define ACPI_FUNCTION_NAME(a) ACPI_DO_WHILE0 +#define ACPI_FUNCTION_TRACE(a) ACPI_DO_WHILE0 +#define ACPI_FUNCTION_TRACE_PTR(a, b) ACPI_DO_WHILE0 +#define ACPI_FUNCTION_TRACE_U32(a, b) ACPI_DO_WHILE0 +#define ACPI_FUNCTION_TRACE_STR(a, b) ACPI_DO_WHILE0 +#define ACPI_FUNCTION_ENTRY() ACPI_DO_WHILE0 +#define ACPI_DUMP_STACK_ENTRY(a) ACPI_DO_WHILE0 +#define ACPI_DUMP_OPERANDS(a, b, c) ACPI_DO_WHILE0 +#define ACPI_DUMP_ENTRY(a, b) ACPI_DO_WHILE0 +#define ACPI_DUMP_PATHNAME(a, b, c, d) ACPI_DO_WHILE0 +#define ACPI_DUMP_BUFFER(a, b) ACPI_DO_WHILE0 #define ACPI_IS_DEBUG_ENABLED(level, component) 0 /* Return macros must have a return statement at the minimum */
When ACPI debugging is disabled, I see warnings like this one: drivers/i2c/busses/i2c-scmi.c: In function "acpi_smbus_cmi_add_cap": drivers/i2c/busses/i2c-scmi.c:328:39: warning: suggest braces around empty body in an "else" statement [-Wempty-body] drivers/i2c/busses/i2c-scmi.c:338:12: warning: suggest braces around empty body in an "else" statement [-Wempty-body] It is caused by ACPI_DEBUG_PRINT (or other similar macros) to resolve to nothing. Make them resolve to the classic "do {} while (0)" construct instead when the compiler likes that, to silent all such warnings. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Len Brown <lenb@kernel.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> --- include/acpi/acoutput.h | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-)