CVS log for src/usr.bin/xlint/lint1/err.c

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lint: warn about do-while macros that end with a semicolon

lint: warn about function definitions that still use identifier lists

lint: add back optimization for non-query mode

The main point of the optimization is to skip the expensive calls to
type_name when preparing the message details.  This was not spelled out
explicitly in the comment.

While here, fix the stray 'previous declaration' message that occurred
whenever a function was first declared as 'static' and later defined
without 'static', see query 16.

lint: remove premature optimization for non-query scenarios

lint: add queries for typedefs to struct/union and their pointers

As suggested in share/misc/style since 1.75 from August 2023.

These are queries instead of warnings as the number of false positives or
historical practice is too high; these queries are only intended for
detecting these typedefs on newly added types.

lint: use separate message when discarding a qualifier in call

lint: add details to messages about discarding qualifiers

The related message 153 is left as-is, as it is used in two places, and
the second place is not only about discarded qualifiers.

lint: add more details to 'statement not reached' message

In lib/libcompat/regexp/regexp.c, the FAIL macro expands to a compound
statement containing a function call statement and a return statement,
and the macro invocation is followed by a semicolon, forming an extra
empty statement.  Which of these statements is unreachable now becomes
clear from the diagnostic, without having to inspect the preprocessed
source code.

lint: allow enum constant named 'N_*' to exceed the array index

Seen in libxcb.

While here, add the name of the enum constant to the message, to quickly
decide whether the identifier is outside the range of expected enum
values, thus marking the number of enum constants.

lint: add details to message about too large integer constant

lint: add more details to messages about hidden symbols

lint: only skip assertion failure in fuzzing mode

Skipping the assertion message after seeing a syntax error in the parser
was surprising, as there was no information about the assertion that
failed.

lint: reword warning about cast between unrelated pointer types

The phrase "may be troublesome" was too unspecific to be useful.

lint: add warning for '!(var = constant)'

This catches expressions like 'ATF_CHECK(errno = ENOENT)', which was
intended to use '==' instead of '='.

lint: warn about lossy floating point constant to integer conversions

lint: add details to warnings about negative constant to unsigned

lint: add wrapper for <ctype.h> functions, for strict bool mode

When using the Clang preprocessor (with MKLLVM=yes), the preprocessor
output does not indicate which tokens come from a system header and
which tokens come from the user code.  Lint's strict bool mode relies on
this information to treat the character classification functions from
<ctype.h> as if their return type were bool instead of int.

These wrapper functions are only used when their argument is indeed a
'char', but not when the argument might be 'EOF or representable as an
unsigned char', such as when reading a byte from the input.

lint: warn when comparing an integer to a floating point constant

lint: add details to message about too many initializers

lint: add query for conversion from void pointer to other pointer

lint: in snprintb, warn about all escaped characters in descriptions

lint: add query for implicit integer-to-floating conversion

lint: do not convert array subscripts from size_t to ptrdiff_t

The C standards do not specify a fixed type for an array subscript, it
just has to be an integer type.  Previously, query 4 fired for the
ubiquitous expression 'ptr[sz]' when sz had type 'size_t'.

The test platform_ilp32_long is unaffected by this change, as the
integer constant 0x80000000 has type 'unsigned int', while size_t is
'unsigned long' on those platforms, and even though the types 'unsigned
int' and 'unsigned long' have the same value space, there's still a
conversion, at least for now.

lint: reword messages about array subscripts to sound more natural

lint: fix wording of warning about bit-field initializer

lint: clean up

lint: don't use 'long' in diagnostics

The size of 'long' differs between 64-bit and 32-bit platforms.
Eliminate this possible platform-dependency.

lint: rename snprintb 'directives' to 'conversions'

This aligns the terminology with the snprintf function.

lint: add details to the message about integer overflow

Having only the operator was too unspecific to be actionable, so add the
actual numbers and the data type.

lint: warn about escaped snprintb directive

Repurpose message 362, as the previous version was redundant since null
bytes in old-style formats are already covered by message 371 (bit
position out of range) and 377 (redundant '\0' at the end).

lint: fix warning about "empty" single-letter snprintb descriptions

lint: check for unreachable bits and fields in snprintb formats

While here, clean up a few existing checks.

lint: check snprintb formats for overlapping bits and fields

lint: remove custom wrappers around <ctype.h> functions

lint: test format strings from snprintb calls

The functions snprintb and snprintb_m are specific to NetBSD, and their
format strings are tricky to get correct.  Provide some assistance in
catching the most common mistakes.

lint: tab-align message numbers in err.c

By replacing block comments with end-of-line comments, the comments take
up less space and thus no longer require to be indented by 6 spaces.

The messages and their comments are used in 3 places: the manual page
lint.7, the err-msgs.h header for debug mode, and check-msgs.lua to
verify that the comments above the message IDs correspond to the actual
messages.

No functional change.

lint: warn about short octal escape followed by '8' or '9'

These mistakes is typically found in snprintb format directives but is
probably a typo everywhere else as well.

lint: add query for const automatic variables

lint: allow querying for invisible characters in literals and constants

lint: allow querying for 'static' followed by non-'static' declaration

lint: in declarations, replace tab with space

Previously, in some cases, the keywords 'const' or 'struct' were
followed by a tab, which doesn't make sense.

No functional change.

lint: re-wrap comments

No functional change.

lint: fix wording of diagnostics about 'C99 extension'

The term 'extension' means an extension to a C standard.  C99 by itself
is not an extension but a revision of the C standard.

lint: make diagnostics about ANSI C more international

lint: make '_Static_assert' only available in C11 or C23 mode

lint: distinguish between arguments and parameters

lint1: remove option -m

The list of lint messages is only needed for generating the manual page
lint.7.  Since 2022-07-06, that list is extracted from the source code
instead of compiling and then running lint1.

lint: reword message about non-constant initializer

lint: indent copyright lines consistently

lint: update wording in diagnostic for C99

lint: when debugging the parser, write messages on stderr

This way, all messages (regular debug, yacc debug, lint diagnostics)
occur in the correct order.

lint: in the warning about ordered enums, mention the affected type

lint: clean up wording in diagnostics

Use the term 'parameter' as defined in C99 3.15.

lint: clean up the wording of a few diagnostics

lint: remove redundant '#' after 'argument' in diagnostics

lint: only skip 'unused' warnings after errors, not other warnings

Previously, in -w mode, any warning suppressed further 'unused'
warnings, even though there was no need to do that.  This can be seen in
the test gcc_attribute_var.c, where only the last unused variable from a
function was marked as unused, the others slipped through.

Fixed by counting the errors and the warnings separately and only
combining them if actually desired.

lint: add initial support for C23

Required by xsrc/external/mit/MesaLib.old, brw_eu_validate.c, which
initializes a struct using empty braces: 'return (struct string){};'.

lint: add query for assigning an integer 0 to a pointer

lint: add query for comparing 'char' with plain integers

lint: add query for redundant 'extern' in function declaration

lint: add query for comma operator

lint: miscellaneous clean-ups

No binary change, except for line numbers in assertions.

lint: indent local variables consistently

No binary change.

lint: add query for static variables in functions

This query allows finding hidden global variables, as an easier-to-read
alternative to 'objdump -t'.

lint: add query for chained assignments

lint: reword message for missing declaration in header

Suggested by Christos.

lint: be strict when parsing command line for excluded message IDs

Previously, lint accepted -X '1, 2, 3', while the manual page lists the
IDs without spaces.

On 32-bit platforms, lint accepted -X -4294967295, and on 64-bit
platforms, it accepted the corresponding larger numbers.

The code for parsing message IDs and query IDs conceptually does the
same, but the implementations differed for no reason.

lint: add query for parenthesized return value

lint: allow querying for octal integer constants

lint: warn about 'extern' declarations inside function bodies

https://mail-index.netbsd.org/tech-userlevel/2023/03/15/msg013727.html

The previous attempt (message 351 about 'extern' declarations outside
headers) did not cover the proposal from the tech-userlevel mailing list
but instead warns about a different usage pattern of the 'extern'
keyword.

lint: warn about extern declarations outside headers

https://mail-index.netbsd.org/tech-userlevel/2023/03/15/msg013727.html

lint: fix confusing message about nonportable character constants

lint: make basename simpler

There is no need to handle trailing slashes since lint only handles
regular files in diagnostics, not directories. Furthermore, only the
last '/' was ignored, but multiple trailing slashes would not.

lint: remove unused internal_error

lint: add support for the C11 type qualifier '_Atomic'

That keyword can be used as a type specifier as well, support for that
will be added later.

lint: improve error message for parsing query IDs

lint: add hyphen to adjective 'old-style'

lint: add more details to message about large bit-shifts

lint: add more details to message about pointer alignment

The previous message 'may cause alignment problem' was not detailed
enough to be actionable, it didn't give the necessary insight to why
lint was complaining at all.

The new message 'increases alignment from 1 to 4' or 'from 2 to 8'
describes the potentially problematic conversion, and together with the
involved type names, it allows an informed decision about whether lint's
warning is warranted or not.

In a typical NetBSD build, this warning is in the top 10.  The number of
these warnings depends on the architecture, it is typically between 800
and 1600.

lint: add additional queries that are not enabled by default

In the last 18 months, several lint warnings have been made adjusted to
allow common usage patterns.  For example, lint no longer warns about a
constant condition in the statement 'do { ... } while (false)' (message
161), as this pattern is well-known in statement-like macros, making it
unlikely that the 'false' is a mistake.  Another example is casts
between unequal pointer types (message 247) for a few well-known
patterns that are unlikely to be bugs.

Occasionally, it is useful to query the code for patterns or events that
would not justify a warning.  These patterns are modeled as predefined
queries that can be selected individually, in addition to and
independently of the existing warnings and errors.

New queries can be added as needed, in the same way as new warnings.
Queries that are deemed no longer used can be deactivated in the same
way as warnings that are no longer used.

As long as none of the queries is enabled, they produce a minimal
overhead of querying a single global variable.  Computations that are
more expensive than a few machine instructions should be guarded by
any_query_enabled.

https://mail-index.netbsd.org/source-changes-d/2022/06/28/msg013716.html

ok christos@

lint: allow message IDs to be only specified in decimal

The message IDs are communicated in decimal everywhere, there's no point
in passing '-X 0x00000084' instead of the clearer '-X 132'.

lint: clean up suppression of warnings and errors

Since lint1.h 1.11 from 2001-12-13, lint1 had been a memory hog.  While
it used a bit set for keeping track of the message IDs of the suppressed
messages, it only used the lower 4 bits of each 32-bit word, due to a
missing CHAR_BIT in __NERRBITS.

As a quick hack, the bit set had 1024 entries, much more than the number
of actual messages, which is currently at 350.  This meant 674 bytes of
wasted memory, plus the code size for the bit manipulations.

The only functional change is that the option '-X' now only accepts
actually valid message IDs.  Previously it had accepted all numbers from
0 to 1023.

lint: move error handling code from main1.c to err.c

No functional change.

lint: add quotes around operator in message 138, remove message 240

Message 138 doesn't occur in practice, it was the last one that was
missing the quotes around the placeholder.

Message 240 was also missing the quotes, but it was not reachable. There
was also no apparent benefit in warning about 'assignment of different
structures' when the message about 'assignment type mismatch' serves the
same purpose.

lint: add quotes around placeholders for the remaining messages

Reword some of the messages slightly, exchanging brevity for clarity.

Message 138 is kept as-is, as it is not yet covered by any tests.

Message 240 is kep as-is, as it is unreachable.

lint: add quotes and details to some more messages

lint: remove redundant include

err.c doesn't use anything from <sys/types.h>, plus it is already
included by "lint.h".

No binary change.

lint: add quotes around several placeholders in messages

lint: add quotes around placeholders in 4 messages

tests/lint: add quotes around placeholders in a few messages

lint: unexport lint's messages

There was only a single place where a message was used directly, instead
of calling one of the several functions for this purpose.

lint: add quotes around placeholders for a few more messages

lint: add quotes around a few more placeholders in messages

lint: prevent assertion failure after parse error from grammar

Instead of running into an assertion failure, the malformed input
'f=({;};}' now generates:

malformed.c(1): error: syntax error ';' [249]
malformed.c(1): warning: ({ }) is a GCC extension [320]
malformed.c(1): warning: ({ }) is a GCC extension [320]
malformed.c(1): error: cannot recover from previous errors [224]

lint: use __RCSID in lint mode as well

Since 1995-10-02, lint supports __asm statements and __asm modifiers.

No binary change.

gcc allows __alignof__(unary-expression)

lint: inline macro 'sflag'

Mark all places where lint's C90 mode is stricter than its C99 mode.

Most of the situations in which lint produces only warnings instead of
errors covered by the "Constraints" sections in the relevant standards.
This doesn't prevent a specific compiler from accepting it though.

No functional change.

lint: inline macro c11flag

No functional change.

lint: migrate gflag to allow_gcc

No functional change.

lint: for gnuism and c99ism, calculate severity

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.

lint: model C language levels in a future-compatible way

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.

lint: remove unused message 70, add some more tests

lint: remove unused message 40

I had not been used since 1995, when lint was imported to NetBSD.

lint: remove unreachable message 'compiler takes alignment of function'

lint: try harder to recover after syntax errors

lint: assertion "false" failed in declarator_name at decl.c:1596
    near msg_022.c:22

lint: add type details to message about 'sizeof(function)'

The code in add_function is severely broken, it mixes up the return type
of the function with the argument types.  For now, at least show the
guessed type in the diagnostic, to allow human readers quickly spot the
bug.

Extend the test cases in decl_direct_abstract.c to show that the
behavior differs unreasonably if the first parameter of the function is
equal to its return type.

lint: add details to message about illegal return type

lint: C99 has been released, so refer to it by its proper name

lint: reword message about bit-field in a union

There is nothing illegal about a bit-field in a union, it is allowed by
C90, C99 and C11.

Fixes PR toolchain/53219.

lint: use C90 instead of C89 when referring to the C standard

lint: fix handling of initializations

The implementation from March 2021 added proper support for designators
but didn't model the brace levels correctly.  In particular, it could
not handle additional braces or omitted braces.  In such a case, lint
skipped the remaining initializers from the initialization.  Due to
this, type errors in the remaining initializers went unnoticed.  Another
effect was that arrays of unknown size were wrongly reported as having
size 0.

Both GCC and Clang recommend placing braces around each sub-type that is
initialized, such as a struct, union or array.  Postfix does not follow
these recommendations, therefore lint had to be disabled in
external/ibm-public/postfix/Makefile.inc.  This commit fixes the bugs
mentioned there.

lint: reword message 187 about too long string literal for initializer

The previous message was imprecise in that it didn't distinguish between
non-terminating and terminating null bytes.

lint: add quotes around placeholders in message 123

lint: warn if an enum name is used for mismatched array access

This helps to keep the enum definition and the straight-forward
implementation of a to_string or name function in sync.

The test for message 241 had to be adjusted because of exactly this bug.
That test defined a bit mask enum but accessed it like a value enum
type.

lint: add more details to warning about nonportable character comparison

Especially when macros are involved, this makes it easier to see that
there is a real problem.

Seen in bin/sh/expand.c:273, where a plain char is compared to numbers
larger than 127.

lint: add more details to error about redeclaration

Message 27 is triggered by several conditions.  The one triggered by
register_vget in sbin/fsck_lfs/vnode.c needs more details than the
others.

lint: fix some more lint warnings

The only remaining warnings are in scan.c, which is a generated Flex
scanner.

No functional change.

lint.7: document removed messages

Having just an empty string as the message was confusing.

lint: remove unused function for generic messages

The function message_at is still used, for information about previous
occurrences of a symbol.

lint: remove unused message about nonportable character escape

It has not been used since at least 2001.

lint: remove unused message for struct without named members

Lint has not produced this message since the rewrite of the
initializations in March 2021.  Structures that consist of only unnamed
bit-fields probably don't occur in practice.

lint: add quotes around placeholder in message 141

lint: use standard quotes in messages 203 and 271

lint: add more details to message about redeclared tag

lint: use standard quoting style for messages 124 and 184

lint: warn about 'char * = strchr(const char *, int)'

Found in findcc.c, there are about 25 other instances of this
incongruency in the whole source tree.

For more examples of functions from the C Standard Library that
implicitly remove the 'const' qualifier from an argument, see the C++
include file 'cstring'.

lint: union casts are only available as a GCC extension, not in C99

lint: add quotes around placeholder in message 214

function '%s' expects to return value

lint: clean up debug logging

The calls to debug_step, unlike printf, don't need a trailing newline.

Remove the debug_step0 macro and its relatives since lint already uses
enough other features from C99 that it essentially requires this
standard, which supports varargs macro arguments.  Among these features
are __func__ and printf("%zu").

In non-debug mode, do not evaluate the arguments of debug_step.
Evaluating the arguments had caused an internal error when running the
test op_shl_lp64.  This is indeed a bug since initdecl should have
initialized the type table for __uint128_t.  This had been forgotten
when support for __uint128_t was added in decl.c 1.69 from 2018-09-07.

No functional change.

lint: add type information to message about invalid cast

This probably doesn't matter in practice since the compiler is supposed
to catch this kind of error.  Adding the type information mainly ensures
that parsing abstract type names works as specified.

lint: remove message 66 about missing semicolon in struct-declaration

lint: fix wording of message for incomplete struct (2021-07-04)

A struct member is not an argument.  In err.c 1.124 from 2021-07-04, the
wording had been changed, without noticing that the message was used
twice: once for an argument, once for a struct member.

lint: add quotes around placeholders in message 23 and 232

lint: flush stdout before an internal error

Previously, the internal error may have appeared too early in the
output.  Provoking internal errors and assertion failures is still easy,
just run afl-fuzz for a few seconds.

lint: rename message 340 to talk about "GCC extension", not "GNU"

lint: align messages for invalid left operand of '.' or '->'

lint: improve wording for incomplete struct or union

lint: fix segmentation fault on malformed preprocessor output

# 0 ""
# 0 ""2

Found using afl, does not happen in practice though since every C
preprocessor generates balanced 'enter' (1) and 'leave' (2) events.

lint: mention the name of an implicitly declared function

In the regular NetBSD builds, this happened in swab.c:65.  That line
contains __predict_false, which may or may not be a macro.  In other
cases, there may be more than one function call in a single line.

lint: add type information to message 155 (type mismatch)

lint: require C11 for _Generic

This does not have any effect in practice since the option -g
(originally meant for GCC extensions to the C standards) implicitly
allows all features from C11, since err.c 1.111 from 2021-04-14.

Since the default lint flags for NetBSD builds include the option -g,
this allows all C11 features.

Currently it is not possible to say "allow GNU extensions but not C11".

sync with head

lint: add more specific warning for bit-field of type plain 'int'

Previously, declaring a bit-field of type plain 'int' resulted in this
warning:

	warning: nonportable bit-field type 'int' [34]

This warning was too unspecific to be actionable, and until yesterday it
didn't even include the type.  In order to allow this warning to be
understood and properly fixed, describe the actual nonportability more
precisely:

	warning: bit-field of type plain 'int' has
	implementation-defined signedness [344]

lint: add type information to unportable bit-field type

Seeing the message "unportable bit-field type 'int'" may sound strange
at first, but that's a strict interpretation of the wording in C99
6.7.2.1p4, which requires that the bit-field type is "'_Bool', 'unsigned
int' or 'signed int', or some other implementation-defined type".

The rationale for C99 6.7.2.1 explicitly lists plain 'int' among the
allowed types for bit-fields, regardless of any additional
implementation-defined types.  This means that lint had interpreted this
paragraph wrong, and it should be fixed to allow plain int as well.

lint: add quotes to message 309 about constant conversion

lint: pass pos_t via const pointer

Thanks for the suggestion, christos@.

lint: rename parameter to diagnostic functions and macros

The first parameter is not just an arbitrary number, it's a message ID.

lint: flip parameters in verror_at, vwarning_at, vmessage_at

The parameters are in the same order now as in the corresponding macros.

lint: add error_at, warning_at, message_at

Right now there are several places in the code that use the global
variable curr_pos for passing a parameter to the diagnostic functions.
That's not what global variables are for.

Make it easy for the code to migrate to the parameter-passing style.

No functional change.

lint: do not allow the diagnostics to be modified

gnu enables c11 extensions

lint: add option to accept C11 features

The list of available letters for the command line options gets shorter
and shorter.  Most of the interesting letters are already used for some
warning categories.  Curiously, -A, -W and -E were all still available.

The option -A nicely matches the intention of the option, which is to
allow a certain set of language features.  To keep the option available
for further extensions, define -Ac11 as the currently only valid option
of that kind.  This allows straight-forward extension for C17 and future
language standards, as well as independent feature-sets.  The options -W
and -E may someday complement the -A option, using the allow/warn/error
categories.

lint: remove redundant condition in update_location

lint: add support for C11-isms such as int[static 3]

support parsing c99's static class for array size expressions.

lint: quote placeholders in messages for unused variables

lint: clean up handling of preprocessing output lines

No functional change.

lint: in code from included files, print stack trace

Previously, the standard NetBSD build generated several lint warnings in
lhash.h from OpenSSL, without providing any hint as to which file
actually included that header.  In cases like these, lint now interprets
the line number information in the preprocessor output from GCC to
reconstruct the exact include path to the file in question.

The program check-expect.lua had to be rewritten almost completely since
it assumed that all diagnostics would come from the main file.  In all
existing tests, this was true, but these tests did not cover all cases
that occurred in practice.  Now it records the complete location of the
diagnostic instead of just the line number.

lint: add details to warning about too large shift amount

The previous message 'shift greater than size of object' was too short
to give reasonable hints, especially when the expressions involve
typedefs or macros.

lint: warn about for wrong type cast in argument to ctype.h functions

The argument to most of the functions from <ctype.h> "shall either be
representable as an 'unsigned char' or shall equal the value of the
macro EOF".

When confronted with the infamous warning 'array subscript has type
char', there are enough programmers who don't know the background of
that warning and thus fix it in a wrong way.  Neither GCC nor Clang
explain its warning to target these programmers.

Both GCC and Clang warn about 'array subscript has type char', but they
ignore the other requirements of the <ctype.h> functions, even though
these are in the C standard library.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94182
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95177
https://stackoverflow.com/a/60696378

lint: reword message about constant argument to '!'

In the other messages, operators are typically written in their literal
form as well.  Using single quotes disambiguates them from normal
punctuation.

lint: add parentheses after sizeof, as required by share/misc/style

No functional change.

lint: add type information for message about unknown member name

lint: add type information to message 175

lint: remove wrong warning about wrong initializer type

The following code is valid:

	int valid = {{{ 3 }}};

C90 3.5.7 and C99 6.7.8 both say that the "initializer for a scalar
shall be a single expression, optionally enclosed in braces".  They
don't put any upper bound on the amount of braces, not even in the
"Translation limits" section.

lint: rename LERROR to INTERNAL_ERROR

The '#ifndef' in tyname.c is meant to distinguish between lint1 and
lint2, it is not meant to be defined from anywhere outside the lint code
itself.

No functional change.

lint: add quotes around placeholder in message about undefined variable

Before: error: expected undefined [99]
After:  error: 'expected' undefined [99]

Seen in external/mpl/bind, which for Clang defines in stdatomic.h:
> #define atomic_exchange_explicit(obj, desired, order) \
>     __c11_atomic_exchange_explicit(obj, expected, order)
Note the mismatch between 'desired' and 'expected'.

lint: improve output format for internal errors

The new format follows the common conventions for file locations and
allows quick navigation in IDEs.

To trigger an internal error, it suffices to have 2 tokens in lint1's
input, after preprocessing: 'void __pure'.

lint: in malloc calls, use 'sizeof *ptr' instead of 'sizeof(type)'

No functional change.

lint: use precise type information in message about type mismatch

While here, reword the message, avoiding operators and parentheses.

Since 2021-01-02, providing the precise type name is as easy as the
broad type classification (just replace tspec_name with type_name), and
it's definitely more useful to the human readers.

lint: prefix error messages with 'error:'

This makes it easier to find these errors in the build logs.

lint: remove redundant prototypes

No functional change.

lint: properly name C99 in message about declaration after statement

Now that C99 has been released and published, there is no reason anymore
to refer to it as C9X.

lint: reword message about type mismatch in initialization

Using parentheses for quotes is unusual, furthermore the previous
message didn't follow proper grammar rules, sacrificing clarity for
brevity.

lint: in strict C mode, warn about initialization with '[a ... b]'

https://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html

lint: add type information to 'illegal bit-field type'

lint: add type information for 'incompatible struct pointers'

lint: add type information to enum type mismatch

lint: make messages for incompatible pointers more specific

Message 153 didn't state obviously which of the pointer types was the
one before conversion (or cast) and which was the resulting type.

Message 229 didn't have any type information at all.

lint: add type information to 'possible pointer alignment problem [135]'

This warning occurs more than 7400 times in a regular NetBSD build, and
without giving any type information, leaves the reader clueless about
what the underlying issue might be.  Add type information since that is
a no-brainer to implement.

lint: change spelling of initialisation to initialization

That's the wording from the ISO C99 standard.

lint: add type information to message about enum mismatch

lint: warn about mismatch in getopt handling

lint: add back "due to prototype" to message 259

That message is only supposed to warn about compatibility to traditional
C, in case the function should ever be compiled without its prototype
being in effect.  All other type checks are supposed to be in another
function, as documented, but that type check misses to report a few
error-prone type combinations (long to char, long to int).

30 years after the introduction of prototypes with C90, almost all
existing code uses prototypes.  The warning has thus lost most of its
usefulness and can rather be confusing since a conversion from 'char' to
'long' is not problematic with prototypes in action, and the probability
of the code being backported to a pre-C90 compiler is diminishingly
small.

The words "due to prototype" now serve as a hint again.  The proper fix
could be to suppress this warning in C99 mode since that's far enough
from traditional C.

lint: reword message 259 about function argument conversion

The words "due to prototype" are an anachronism from the 1990s.
Nowadays every function is defined using a prototype, which makes these
words redundant.

lint: make warning about function argument conversion more detailed

For every conversion it is useful to know both the source and the target
type since these are not always obvious from the code.

The only surprise is the warning in d_gcc_extension.  The conversion
there is from 'double' to 'long double', which is a lossless conversion.
This may be a bug in lint.

lint: mention the operator in messages about bit shifts

lint: add quotes to messages 1 and 19

lint: be more precise in message 003 "tag in argument list"

lint: add type information to message 275

Before:	cast discards 'const' from pointer target type
After:	cast discards 'const' from type 'pointer to const char'

Seen in sqlite3.c.

lint: add type information to warning about troublesome casts

The previous warning text did not mention the actual types that are
involved in the type conversion.  These types can be hard to see from
the source code as soon as macros are involved, and even in plain code,
one would have to follow the declarations, which is an unnecessary
burden.  Lint already has all information about the involved types, so
there is no reason for omitting this crucial information.

Seen in external/mit/lua/dist/src/lvm.c and several other files.
Including the type information in the message immediately makes the
message scarier.

Before:	pointer casts may be troublesome
After:	pointer cast from 'pointer to struct TString' to 'pointer to
	union GCUnion' may be troublesome

lint: remove message 189, add tests for a few other messages

Message 189 would have applied to traditional C and was supposed to
detect assignments between struct and union types.  The corresponding
check had never been implemented though.

Traditional C has been superseded for 30 years now, therefore there is no
point in adding this check retroactively.

lint: add type information to message 126

lint: rename local variables in lbasename

lint: add type details to message for enum type mismatch

Before December 2020, it was cumbersome to add type information to a
message since the caller had to explicitly allocate buffers for the type
names.  That's probably the reason why this crucial detail had been left
out of the warning.

lint: add new check for strict bool mode

In strict bool mode, bool is considered incompatible with all other
scalar types, just as in Java, C#, Pascal.

The controlling expressions in if statements, while loops, for loops and
the '?:' operator must be of type bool.  The logical operators work on
bool instead of int, the bitwise operators accept both integer and bool.
The arithmetic operators don't accept bool.

Since <stdbool.h> implements bool using C preprocessor macros instead of
predefining the identifiers "true" and "false", the integer constants 0
and 1 may be used in all contexts that require a bool expression.
Except from these, no implicit conversion between bool and scalar types
is allowed.

See usr.bin/tests/xlint/lint1/d_c99_bool_strict.c for more details.

The command line option -T has been chosen because all obvious choices
(-b or -B for bool, -s or -S for strict) are already in use.  The -T may
stand for "types are checked strictly".

The default behavior of lint doesn't change.  The strict bool check is
purely optional.

An example program for strict bool mode is usr.bin/make, which has been
using explicit comparisons such as p != NULL, ch != '\0' or n > 0 in
most places for a long time now, even before the refactoring in 2020.

lint: fix crash for error 108 (invalid type of unary operator)

lint: in DEBUG mode, verify printf parameters for messages

Since several years GCC validates printf-style strings, and there is no
reason not to let GCC do that work.  This prevents bugs like the
segmentation fault that was fixed in tree.c 1.109 from 2021-01-01.

By default, lint is compiled with DEBUG off, but it's easy enough to
compile it in debug mode once in a while.

lint: let gnuism and c99ism return void instead of int

The return value was only used in a single case.  Duplicating the
condition for printing a message is ok in that case, since it makes all
other places in the code simpler.

The occasional "(void)" or "msg = " before the function call had hidden
the calls from check-msgs.lua, which didn't check the message texts in
such cases.

lint: fix spelling of message 308

All other messages are lowercase as well.

lint: add type information to message 124 "illegal pointer combination"

lint: fix message 308 "Invalid type for _Complex"

Previously, lint aborted since it didn't expect tspec_name to be called
with NOTSPEC, which at that point was the only possible value of
dcs->d_cmod.

lint: reduce verbosity of assertions

Having 2 lines of source code per assertion is too much, especially
since most of this code is redundant anyway.  Extract the common code
and the additional negation into a simple function instead.

lint: fix indentation and alignment that used space-tab

lint: remove redundant parentheses around return value

lint: spell check

lint: sort includes

Fix return of alignof()

Sync with HEAD

Ssync with HEAD

recognize int128

fix indent

Add union casts.

anonymous members are C9X

more descriptive errors

Be more specific about the type errors

Rebase to HEAD as of a few days ago.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

add __extension__ and typeof

resync from head

Allow linted comments to take an argument that defines which error to suppress.

sync with head.

add __PRETTY_FUNCTION__

Handle c99 declarations in the middle of blocks.

understand __attribute__((__packed__)) and __packed.

Sync with HEAD.

Third (and last) commit. See http://mail-index.netbsd.org/source-changes/2009/05/13/msg221222.html

Add __alignof__.

add variable declarations in for loops for c99

Lukemify (WARNS=4)

since we know the types, print what they are in error messages.

Sync with wrstuden-revivesa-base-2.

Add Picky flag; this produces more warnings:
1. long a; int i; a = i * i;
   suggests casting i to long, so that we gain precision in the multiplication.
2. warns about magnitude comparisons in enums.
3. warns about possible sign extension issues when integer types become widened.

Add a check for 'continue' inside a 'do ... while (0)' loop.
'continue' has the same effect as 'break' - as that probably isn't
what the writer had in mind!

sync with head.

print the types involved in an error.

reorder a couple of error messages.

fix "long double" type recognition which broke with the complex changes.

preliminary _Complex support.
NB: Does not really understand type conversions between complex and doubles.

sync with head.

sync with HEAD

PR/38142: YAMAMOTO Takashi: lint -S complains on variable length arrays

allow 0 sized structs in c9x

add zero sized array handling. It is a little too chatty now.

say from what type to what time we are converting.

recognize C99 array initializer designators.  PR/18896.

Pull up revision 1.27 (requested by jmc in ticket #527):
Completely rework how tools/compat is done. Purge all uses/references to
_NETBSD_SOURCE as this makes cross building from older/newer versions of
NetBSD harder, not easier (and also makes the resulting tools 'different')
Wrap all required code with the inclusion of nbtool_config.h, attempt to
only use POSIX code in all places (or when reasonable test w. configure and
provide definitions: ala u_int, etc).
Reviewed by lukem. Tested on FreeBSD 4.9, Redhat Linux ES3, NetBSD 1.6.2 x86
NetBSD current (x86 and amd64) and Solaris 9.
Fixes PR's: PR#17762 PR#25944

Completely rework how tools/compat is done. Purge all uses/references to
_NETBSD_SOURCE as this makes cross building from older/newer versions of
NetBSD harder, not easier (and also makes the resulting tools 'different')

Wrap all required code with the inclusion of nbtool_config.h, attempt to
only use POSIX code in all places (or when reasonable test w. configure and
provide definitions: ala u_int, etc).

Reviewed by lukem. Tested on FreeBSD 4.9, Redhat Linux ES3, NetBSD 1.6.2 x86
NetBSD current (x86 and amd64) and Solaris 9.

Fixes PR's: PR#17762 PR#25944

add a comment on c99ism noting that the logic might be wrong but we
haven't yet decided on what combinations of -s and -S really are
intended to mean yet.

add c99ism(), by analogy to gnuism(), for c99 construct (un)warnings

add support for ({}) gcc shit.

add C9X/GCC compound literal expressions.

add variable array dimension.

handle gcc __FUNCTION__ and C9X __func__

support for c99 style and gnu style structure and union named initializers.

Minimize diffs with my C99 capable version [this commit does not include
C99 support.

- turn lerror() into a macro so that the filename and the line number of the
  error are printed before we abort.
- recurse in type printing to provide the proper type name.

Rename `basename' as `lbasename' so as not to confuse with the libgen.h
prototyped function of the same name.

Protect __RCSID and __COPYRIGHT from being invoked if not defined.

Don't use fd_set to keep track of errors to ignore.  Doing so relies on
overriding FD_SETSIZE.  Not overriding it makes it stomp all over memory
(which caused the debug outputs we've seen lately).
It used to work, but toolification of lint broke it.

cleanup (prior to more adding more features):
- convert to ANSI KNF
- remove trailing whitespace
- translate some comments from german into english

code compiles and runs clean, and tested by running "make lint" against
xlint source using previous and this lint produces same results.

support // comments if -g is given

fix broken NetBSD RCS id tags

- support for -X flag
- support for -m flag
- print the error number in each message

Fix a recurring typo: comparision -> comparison.

WARNSify

Pull up from trunk: make renaming work and other minor fixes.

implement (hack in) symbol (function and variable) renaming, so that
the function renaming tricks currently needed by libc can be tolerated
by lint.  This needs some cleanup, but it appears to work.

removed some dubious warnings about conversion of constant operands of
bitwise operators

LINTED and CONSTCOND are now valid up to the next end of a
global or local declaration/definition/statement. Originally they were
valid on the current and next line, which made it hard to suppress
warnings in constructs with more then one line.

LONGLONG can now be used to suppress errors or warnings in the next
declaration, definition or statement.

some minor bug fixes

prototypes override old style function definitions
this is a gnu extension to ansi c

__{const,signed,volatile}{__,} added
const, signed and volatile are disabled with -t

added inline keywords
"inline" is enabled by -g, "__inline" and "__inline__" are always available

RCS id cleanup

lint(1) implementation, by Jochen Pohl.  named 'xlint' for a similar
reason to why 'install' is named 'xinstall'.

Initial revision