Hi,
On Wed, 5 Aug 2020 at 13:32, Tom Rini trini@konsulko.com wrote:
On Wed, Aug 05, 2020 at 09:08:40PM +0200, Heinrich Schuchardt wrote:
Am 5. August 2020 21:03:28 MESZ schrieb Tom Rini trini@konsulko.com:
On Wed, Aug 05, 2020 at 12:56:17PM -0600, Simon Glass wrote:
Hi Tom,
On Wed, 5 Aug 2020 at 12:37, Tom Rini trini@konsulko.com wrote:
On Wed, Aug 05, 2020 at 08:31:55PM +0200, Heinrich Schuchardt
wrote:
On 05.08.20 14:56, Tom Rini wrote: > On Wed, Aug 05, 2020 at 02:54:05PM +0200, Heinrich Schuchardt
wrote:
>> On 05.08.20 14:18, Tom Rini wrote: >>> On Sun, Jul 26, 2020 at 08:27:35PM -0600, Simon Glass wrote: >>> >>>> At present if CONFIG_LOG enabled, putting LOG_DEBUG at the
top of a file
>>>> (before log.h inclusion) causes _log() to be executed for
every log()
>>>> call, regardless of the build- or run-time logging level. >>>> >>>> However there is no guarantee that the log record will
actually be
>>>> displayed. If the current log level is lower than LOGL_DEBUG
then it will
>>>> not be. >>>> >>>> Add a way to signal that the log record should always be
displayed and
>>>> update log_passes_filters() to handle this. >>>> >>>> Signed-off-by: Simon Glass sjg@chromium.org >>> >>> This exposes an underlying problem with LOG and clang I
believe:
>>> https://gitlab.denx.de/u-boot/u-boot/-/jobs/135789 >>> >> >> include/log.h:147:44: note: expanded from macro 'log' >> if (CONFIG_IS_ENABLED(LOG) && (_LOG_DEBUG || _l <= >> _LOG_MAX_LEVEL)) \ >> ^ >> drivers/misc/p2sb_emul.c:197:10: error: converting the enum
constant to
>> a boolean [-Werror,-Wint-in-bool-context] >> >> This seems to be a Clang bug. _LOG_DEBUG is not an enum: >> >> #if CONFIG_IS_ENABLED(LOG) >> #ifdef LOG_DEBUG >> #define _LOG_DEBUG 1 >> #else >> #define _LOG_DEBUG 0 >> #endif >> >> So there seems to be a bug in the Clang you used. >> >> Compiling with clang on Debian Bullseye does not show the
problem:
>> >> make HOSTCC=clang sandbox_defconfig >> make HOSTCC=clang CC=clang -j8 >> >> clang version 9.0.1-13 >> LLVM version 9.0.1 >> >> Which Clang version did you use? >> >> This is the change that added the test: >> https://reviews.llvm.org/D63082 >> >> -Wint-in-bool-context seems to be new in Clang 10. >> >> All over the U-Boot code we assume that a non-zero integer is
true. Do
>> we really want to enable -Wint-in-bool-context? > > I'm using the official Clang 10 stable builds. >
Do you really want to forbid using integers as booleans (-Wint-in-bool-context)?
So, interesting. The Linux kernel isn't disabling this warning.
It's
mentioned in two commits, one of which is "clang found a bug here",
of
which this is not the case. The other is more like ours: commit 968e5170939662341242812b9c82ef51cf140a33 Author: Nathan Chancellor natechancellor@gmail.com Date: Thu Sep 26 09:22:59 2019 -0700
tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGNmacro
After r372664 in clang, the IF_ASSIGN macro causes a couplehundred
warnings along the lines of: kernel/trace/trace_output.c:1331:2: warning: converting theenum
constant to a boolean [-Wint-in-bool-context] kernel/trace/trace.h:409:3: note: expanded from macro 'trace_assign_type' IF_ASSIGN(var, ent, structftrace_graph_ret_entry,
^ kernel/trace/trace.h:371:14: note: expanded from macro'IF_ASSIGN'
WARN_ON(id && (entry)->type != id); \ ^ 264 warnings generated. This warning can catch issues with constructs like: if (state == A || B) where the developer really meant: if (state == A || state == B) This is currently the only occurrence of the warning in thekernel
tree across defconfig, allyesconfig, allmodconfig for arm32,arm64,
and x86_64. Add the implicit '!= 0' to the WARN_ON statement tofix
the warnings and find potential issues in the future. Link:https://github.com/llvm/llvm-project/commit/28b38c277a2941e9e891b2db30652cfd...
Link: https://github.com/ClangBuiltLinux/linux/issues/686 Link:http://lkml.kernel.org/r/20190926162258.466321-1-natechancellor@gmail.com
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>Which is like our case, and reworking the test to be explicit. I
lean
towards that.
Oh dear I really want to vote against that.
if (x)
should allow C to consider x to be a boolean. I am hitting this in Zephyr and feels like it is undoing a long-standing C feature, with major disruption, for no benefit I can detect.
Hopefully I am misunderstanding what -Wint-in-bool-context means, and it just applies to enums?
Yes, it's not the simple case, it's the complex case as noted in the kernel commit message. Our change I believe would be:
diff --git a/include/log.h b/include/log.h index 2859ce1f2e72..91ca2e0523f7 100644 --- a/include/log.h +++ b/include/log.h @@ -141,7 +141,7 @@ static inline int _log_nop(enum log_category_t cat, enum log_level_t level, /* Emit a log record if the level is less that the maximum */ #define log(_cat, _level, _fmt, _args...) ({ \ int _l = _level; \
- if (CONFIG_IS_ENABLED(LOG) && (_l <= _LOG_MAX_LEVEL || _LOG_DEBUG)) \
- if (CONFIG_IS_ENABLED(LOG) && (_l <= _LOG_MAX_LEVEL || _LOG_DEBUG ==
1)) \
Why wouldn't we define _LOG_DEBUG as true or false? Shouldn't clang know that true is boolean?
Because I didn't think of that instead, mainly.
I've resent this patch with just this change to fix clang-10.
Regards, Simon