On Wed, Aug 05, 2020 at 09:08:40PM +0200, Heinrich Schuchardt wrote: > Am 5. August 2020 21:03:28 MESZ schrieb Tom Rini <tr...@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 <tr...@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 <s...@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 <natechancel...@gmail.com> > >> > Date: Thu Sep 26 09:22:59 2019 -0700 > >> > > >> > tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN > >macro > >> > > >> > After r372664 in clang, the IF_ASSIGN macro causes a couple > >hundred > >> > warnings along the lines of: > >> > > >> > kernel/trace/trace_output.c:1331:2: warning: converting the > >enum > >> > 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, struct > >ftrace_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 the > >kernel > >> > tree across defconfig, allyesconfig, allmodconfig for arm32, > >arm64, > >> > and x86_64. Add the implicit '!= 0' to the WARN_ON statement to > >fix > >> > the warnings and find potential issues in the future. > >> > > >> > Link: > >https://github.com/llvm/llvm-project/commit/28b38c277a2941e9e891b2db30652cfd962f070b > >> > Link: https://github.com/ClangBuiltLinux/linux/issues/686 > >> > Link: > >http://lkml.kernel.org/r/20190926162258.466321-1-natechancel...@gmail.com > >> > > >> > Reviewed-by: Nick Desaulniers <ndesaulni...@google.com> > >> > Signed-off-by: Nathan Chancellor <natechancel...@gmail.com> > >> > Signed-off-by: Steven Rostedt (VMware) <rost...@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. -- Tom
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