https://pubs.opengroup.org/onlinepubs/9699919799/utilities/make.html
says that in order to make a makefile POSIX-conforming, its first
non-comment line must be the special dependency line '.POSIX:' without
any source dependencies.
Previously, make switched to POSIX mode even if such a line occurred
anywhere else, which was allowed by POSIX but was deep in the
"unspecified behavior" area. For NetBSD make, there is no big
difference since it doesn't ship any <posix.mk> file, this change mainly
affects the bmake distribution.
Previously, makefiles that contain '.POSIX:' somewhere in the middle
could fail due to <posix.mk> resetting .SUFFIXES, among other things.
Suggested by Simon J. Gerraty, who also reviewed an earlier version of
this change.
The flags do not describe the left operand of the node but both, as for
most operators, either none or both operands are in test context or in
value context.
The one exception is the operator '?' from the '?:' conditional, for
which the left operand is in test context and the right operand is in
value context.
No binary change.
Noticed in lex.c, in the macro kwdef, where lint complains about the
condition containing '||' but not about the conditions containing only
'>' or '=='.
The C11 keywords had been listed as being C99 keywords. Instead of
initializing the individual fields separately, merge them by specifying
the year of the standard in which they appeared.
No binary change, except for line numbers in assertions.
There is only one specialized keyword that is also a GCC attribute, it's
"section". All other keywords passed 0 in that macro argument.
No binary change.
Calculating the severity as a simple sum removes the condition sequence
'a && !b, or else a || !b', which can quickly become a brain twister,
especially when negations are involved.
No functional change.
The options -t, -s and -S are confusing because they are used
inconsistently. The option -S enables C99 features, but when using it
instead of -s, it also doesn't enable all checks required by C90 and
later. Prepare fixing of these inconsistencies by replacing the flag
variables with language levels that can be extended in a
straight-forward way as new C standards arrive.
| option | allow_trad | allow_c90 | allow_c99 | allow_c11 |
|--------|------------|-----------|-----------|-----------|
| -t | x | - | - | - |
| (none) | x | x | - | - |
| -s | - | x | - | - |
| -S | - | x | x | - |
| -Ac11 | - | x | x | x |
Each usage of the old flag variables will be inspected and migrated
individually, to clean up the subtle variations in the conditions and to
provide a simpler model.
When lint was created in 1995, its focus was migrating traditional C
code to C90 code. Lint does not help in migrating from C90 to C99 or
from C99 to C11 since there are only few silent changes, and simply
because nobody took the time to implement these migration aids. If
necessary, such migration modes could be added separately.
There is a small functional change: when the option -s is combined with
either -S or -Ac11, lint now only keeps the last of these options.
Previously, these options could be combined, leading to a mixture of
language levels, halfway between C90, C99 and C11. Especially combining
traditional C with C11 doesn't make sense, but xlint currently allows
it.
The 3 tests that accidentally specified multiple language levels have
been adjusted to a single language level.
This removes many of the currently 26.000 'multiply defined' lines from
a typical NetBSD build. Duplicate libraries happen a lot due to
overlapping transitive dependencies. An example is usr.bin/telnet,
which links to -lcrypto and several other libraries twice.
Message 259 is "argument #%d is converted from '%s' to '%s' due to
prototype", and it is intended to warn about compatibility between
traditional C where functions had no prototypes and standard C where
functions have prototypes.
Running lint in C99 mode is further away from traditional C than running
lint in C90 mode, so that warning doesn't make sense for C99. There are
still some inconsistencies in the 5 language version modes that lint
offers:
-t for traditional C
(no option) for migrating traditional C to C90
-s for C90 code
-S for C99 code
-Ac11 for C11 code
By disabling warning 259 in C99 mode, a typical NetBSD build produces
14.500 fewer warnings than before, of about 100.000 total.
Message 259 overlaps with message 298 "conversion from '%s' to '%s' may
lose accuracy, arg #%d", and in some cases of potentially lossy
conversions, lint now produces none of these messages. In some other
cases, these warnings were reported redundantly. The cases where
message 298 makes sense will be added back later, as needed.
Using __CONCAT for identifiers makes it impossible to find their usages
easily, as could be seen in targ.c 1.22 from 2001-07-03. It also
requires that the parts of the identifier are not macros themselves.
No binary change.
When .USEBEFORE was added in targ.c 1.22 from 2001-07-03, it was not
added to Targ_PrintType, probably because the PRINTBIT macro hid the
identifier OP_USE and only used USE.
The bug in deptgt-silent-jobs.mk has been fixed, the debug logging for
comparing conditions and for deleting global variables has changed
intentionally.
lex.c(1451): warning: argument #1 is converted from 'int' to
'unsigned int' due to prototype [259]
A more thorough fix would be to change the type of block_level from int
to size_t, to match mem_block_level, but that change would generate
further signedness warnings because the type of sym_t.s_block_level
would have to be changed from int to size_t as well, but some symbols
have s_block_level == -1, so that's a larger and more error-prone
change. Leave that for later.
Whether message 259 makes sense at all in C99 mode is an entirely
different question that needs to be answered separately.
No functional change.
rillig