Commit graph

197 commits

Author SHA1 Message Date
Christopher Friedt
d0629e3c4e libc: malloc: log an error when malloc is called and arena size is 0
Previously, if the arena size was zero, malloc would always fail.
However, the log message was only visible if debug messages were
enabled. Logging an error will hopefully make it more obvious that
CONFIG_MINIMAL_LIBC_MALLOC_ARENA_SIZE should be >= if the minimal
libc and malloc are both used.

Fixes #26720

Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com>
2020-07-20 12:48:33 +02:00
Josh Gao
c0026346a3 libc: permit users to supply their own malloc.
Severely memory constrained systems with known allocation patterns can
benefit from providing their own implementation of malloc with
specifically tuned bucket sizes. Provide a switch to allow users to
replace the default malloc implementation with their own.

Signed-off-by: Josh Gao <josh@jmgao.dev>
2019-12-12 10:49:52 -06:00
Daniel Leung
b7eb04b300 x86: consolidate x86_64 architecture, SoC and boards
There are two set of code supporting x86_64: x86_64 using x32 ABI,
and x86 long mode, and this consolidates both into one x86_64
architecture and SoC supporting truly 64-bit mode.

() Removes the x86_64:x32 architecture and SoC, and replaces
   them with the existing x86 long mode arch and SoC.
() Replace qemu_x86_64 with qemu_x86_long as qemu_x86_64.
() Updates samples and tests to remove reference to
   qemu_x86_long.
() Renames CONFIG_X86_LONGMODE to CONFIG_X86_64.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
2019-10-25 17:57:55 -04:00
Nicolas Pitre
2129937d3d realloc(): move mempool internal knowledge out of generic lib code
The realloc function was a bit too intimate with the mempool accounting.
Abstract that knowledge away and move it where it belongs.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-09-30 10:57:24 -07:00
Kumar Gala
4cbe5c0961 lib/libc/min: Introduce simple math.h
Introduce math.h to get definitions of float_t and double_t.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2019-09-27 04:30:07 -07:00
Paul Sokolovsky
0173d86e6f lib: posix, minlibc: struct itimerspec is defined by sys/timespec.h
Newlib has it defined in sys/timespec.h, and thus per the established
conventions, everything else relies on it being there. Specifically,
minimal libc acquires sys/timespec.h with a similar definition, and
POSIX headers rely on that header. Still with a workaround for old
Newlib version as used by Xtensa (but all infrastructure for that is
already there; actually, this patch removes duplicate similar-infra,
which apparently didn't work as expected by now, so now we have a
single workaround, not 2 different once).

To emphasize a point, now there 2 headers:

sys/_timespec.h, defining struct timespec, and
sys/timespec.h, defining struct itimerspec

That's how Newlib has it, and what we faithfully embrace and follow,
because otherwise, there will be header conflicts depending on
various libc and POSIX subsys options.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-09-25 20:56:29 -07:00
Peter Bigot
dfd26dbbeb libc/minimal/assert: conditionalize static_assert macro
static_assert was not added to C until C11.  Zephyr builds default to
C99.  To preserve compatibility with newlib avoid defining the
macro at standard levels where it did not exist.

Relates to #17738 and #11754.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-09-19 09:37:42 -05:00
Andy Ross
346cce31d8 kernel: Port remaining buildable syscalls to new API
These calls are buildable on common sanitycheck platforms, but are not
invoked at runtime in any tests accessible to CI.  The changes are
mostly mechanical, so the risk is low, but this commit is separated
from the main API change to allow for more careful review.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-09-12 11:31:50 +08:00
Andy Ross
6564974bae userspace: Support for split 64 bit arguments
System call arguments, at the arch layer, are single words.  So
passing wider values requires splitting them into two registers at
call time.  This gets even more complicated for values (e.g
k_timeout_t) that may have different sizes depending on configuration.
This patch adds a feature to gen_syscalls.py to detect functions with
wide arguments and automatically generates code to split/unsplit them.

Unfortunately the current scheme of Z_SYSCALL_DECLARE_* macros won't
work with functions like this, because for N arguments (our current
maximum N is 10) there are 2^N possible configurations of argument
widths.  So this generates the complete functions for each handler and
wrapper, effectively doing in python what was originally done in the
preprocessor.

Another complexity is that traditional the z_hdlr_*() function for a
system call has taken the raw list of word arguments, which does not
work when some of those arguments must be 64 bit types.  So instead of
using a single Z_SYSCALL_HANDLER macro, this splits the job of
z_hdlr_*() into two steps: An automatically-generated unmarshalling
function, z_mrsh_*(), which then calls a user-supplied verification
function z_vrfy_*().  The verification function is typesafe, and is a
simple C function with exactly the same argument and return signature
as the syscall impl function.  It is also not responsible for
validating the pointers to the extra parameter array or a wide return
value, that code gets automatically generated.

This commit includes new vrfy/msrh handling for all syscalls invoked
during CI runs.  Future commits will port the less testable code.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-09-12 11:31:50 +08:00
Peter Bigot
849df51666 lib/libc: rearrange for standard use of extern "C"
Consistently place C++ use of extern "C" after all include directives,
within the negative branch of _ASMLANGUAGE if used.

Background from issue #17997:

Declarations that use C linkage should be placed within extern "C"
so the language linkage is correct when the header is included by
a C++ compiler.

Similarly #include directives should be outside the extern "C" to
ensure the language-specific default linkage is applied to any
declarations provided by the included header.

See: https://en.cppreference.com/w/cpp/language/language_linkage
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-08-19 23:36:59 +02:00
Peter A. Bigot
ef4cd6a1ab lib/libc/minimal: Refined handle duplicate time definitions
Follow the approach of newlib to use a file sys/_types.h to specify the
underlying type for POSIX/libc types that must be provided in multiple
headers.  The identifier for this type is in the reserved namespace.

Use this type rather than a specific standard type in all headers that
need to provide the type under its public name.

Remove the inclusion of <sys/types.h> from headers that should not bring
in all symbols present in that header, replacing it with the standard
boilerplate to expose the specific symbols that are required.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
2019-08-09 00:43:09 -07:00
Kumar Gala
daf9f11024 lib/libc/min: Handle duplicate time definitions
time_t and suseconds_t are defined in time.h and sys/types.h.  Handle
the duplication by adding ifdef protection around them similar to what
is being done for other types.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2019-08-09 00:43:09 -07:00
Paul Sokolovsky
7d2df83b51 libc: minimal: Add headers as system includes
This is consistent with how newlib headers are treated, and will
have effect of ninlibc headers to be further down in the include
order. This is important, because some POSIX subsys headers
override those of libc. Without this change, we can't streamline
POSIX build config using zephyr_interface_library_named() cmake
directive, because includes will be in wrong order.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-08-08 14:31:35 +02:00
Peter A. Bigot
8420f43b86 libc: minimal: add strspn and strcspn support
These functions are useful for determining prefixes, as with file system
paths.  They are required by littlefs.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
2019-07-31 09:22:49 -07:00
Peter A. Bigot
b8af1a6a4e libc/minimal: fix reproducibility of gmtime
struct tm has fields that were not being set by the implementation,
causing the test to fail when the uninitialized values were compared
with a static initialized result.  Zero the structure before filling it.

Closes #17794

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
2019-07-31 11:48:18 +03:00
Paul Sokolovsky
6b90a02bb4 libc: minimal: time.h: Don't (re)define struct timespec.
By the latest convention, libc's define struct timespec in
sys/_timespec.h. This is consistent with Newlib and ensures
about errors due to redefinitions.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-07-25 13:50:58 -04:00
Paul Sokolovsky
b7bb48eeac posix: unistd.h: open() doesn't belong here
Per POSIX, open() is defined in <fcntl.h>. fcntl.h in turn comes from
the underlying libc, either newlib, or minimal libc.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-07-25 13:50:58 -04:00
Paul Sokolovsky
1347bf9b48 posix: mqueue.h: Move O_CREAT and friends to fcntl.h
That's the header which is supposed to define them, there was even
FIXME on that in mqueue.h.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-07-25 13:50:58 -04:00
Paul Sokolovsky
3a4553913e posix: struct timespec: Move definition to sys/_timespec.h
POSIX subsys defines struct timespec in <time.h> (as POSIX public
API requires), but newlib defines in in sys/_timespec.h, which
inevitably leads to inclusion order and redifinition conflicts.
Follow newlib way and define it in single place, sys/_timespec.h,
which belongs to libc namespace. Thus, we move current definition
to minimal libc, and will use either minlibc's or newlib's
definition, instead of trying to redefine it.

This is similar to the introduction of sys/_timeval.h done earlier.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-07-25 13:50:58 -04:00
Paul Sokolovsky
3693f85805 posix: Move sys/stat.h to minimal libc
Newlib libc already provides sys/stat.h, so trying to have sys/stat.h
on the level of POSIX subsys inevitable leads to include order and
definition conflicts. Instead (as most of other sys/* includes)
should come from the underlying libc.

While moving, made unrelated change of removing #include <kernel.h>,
to accommodate the change reviewers.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2019-07-25 13:50:58 -04:00
Peter A. Bigot
3e8df8b369 libc: minimal: provide gmtime implementation
Implement the conversion from UNIX time to broken-down civil time per
the gmtime() and gmtime_r() functions.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
2019-07-17 14:04:44 +02:00
Peter A. Bigot
acc1703241 libc: minimal: provide types in time.h
Provide definitions for a subset of the standard time types that must be
provided by this file, in anticipation of supporting civil time in
Zephyr.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
2019-07-17 14:04:44 +02:00
Nicolas Pitre
629bd85612 mempool: significant reduction of memory waste
The mempool allocator implementation recursively breaks a memory block
into 4 sub-blocks until it minimally fits the requested memory size.

The size of each sub-blocks is rounded up to the next word boundary to
preserve word alignment on the returned memory, and this is a problem.

Let's consider max_sz = 2072 and n_max = 1. That's our level 0.

At level 1, we get one level-0 block split in 4 sub-blocks whose size
is WB_UP(2072 / 4) = 520. However 4 * 520 = 2080 so we must discard the
4th sub-block since it doesn't fit inside our 2072-byte parent block.

We're down to 3 * 520 = 1560 bytes of usable memory.
Our memory usage efficiency is now 1560 / 2072 = 75%.

At level 2, we get 3 level-1 blocks, and each of them may be split
in 4 sub-blocks whose size is WB_UP(520 / 4) = 132. But 4 * 132 = 528
so the 4th sub-block has to be discarded again.

We're down to 9 * 132 = 1188 bytes of usable memory.
Our memory usage efficiency is now 1188 / 2072 = 57%.

At level 3, we get 9 level-2 blocks, each split into WB_UP(132 / 4)
= 36 bytes. Again 4 * 36 = 144 so the 4th sub-block is discarded.

We're down to 27 * 36 = 972 bytes of usable memory.
Our memory usage efficiency is now 972 / 2072 = 47%.

What should be done instead, is to round _down_ sub-block sizes
not _up_. This way, sub-blocks still align to word boundaries, and
they always fit within their parent block as the total size may
no longer exceed the initial size.

Using the same max_sz = 2072 would yield a memory usage efficiency of
99% at level 3, so let's demo a worst case 2044 instead.

Level 1: 4 sub-blocks of WB_DN(2044 / 4) = 508 bytes.
We're down to 4 * 508 = 2032 bytes of usable memory.
Our memory usage efficiency is now 2032 / 2044 = 99%.

Level 2: 4 * 4 sub-blocks of WB_DN(508 / 4) = 124 bytes.
We're down to 16 * 124 = 1984 bytes of usable memory.
Our memory usage efficiency is now 1984 / 2044 = 97%.

Level 3: 16 * 4 sub-blocks of WB_DN(124 / 4) = 28 bytes.
We're down to 64 * 28 = 1792 bytes of usable memory.
Our memory usage efficiency is now 1792 / 2044 = 88%.

Conclusion: if max_sz is a power of 2 then we get 100% efficiency at
all levens in both cases. But if not, then the rounding-up method has
a far worse degradation curve than the rounding-down method, wasting
more than 50% of memory in some cases.

So let's round sub-block sizes down rather than up, and remove
block_fits() which purpose was to identify sub-blocks that didn't
fit within their parent block and is now useless.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-16 14:21:21 -07:00
Nicolas Pitre
8e11970378 realloc(): struct sys_mem_pool_block is word aligned
Since commit 39cd2ebef7 ("malloc: make sure returned memory is
properly aligned") the size of struct sys_mem_pool_block size is
rounded up to the next word boundary.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-16 14:42:37 +02:00
Nicolas Pitre
3c0cc08657 prf.c: handle denormals properly
Denormals need to be normalized to be displayed properly.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
53169743d2 prf.c: properly format INF/NAN/zero with prefix
The space or plus prefix must appear when requested even with INF and
NAN. And no zero-padding in that case.

Also, 0.0 and -0.0  are distinct values. It is necessary to display
the minus sign with a negative zero.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
90ec5360be prf.c: fix wrong results with %g conversion
The precision parameter to the %g conversion indicates the maximum
number of significant digits and not the number of digits to appear
after the radix character. Here's a few examples this patch fixes:

                                expected        before
----------------------------------------------------------
printf("%.3g", 150.12)          150             150.12
printf("%.2g", 150.1)           1.5e+02         150.1
printf("%#.3g", 150.)           150.            150.000
printf("%#.2g", 15e-5)          0.00015         0.00
printf("%#.4g", 1505e-7)        0.0001505       0.0002
printf("%#.4g", 1505e-8)        1.505e-05       1.5050e-05

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
132a286c39 prf.c: fix display of float exponent >= 100
The code accounts only for 2 exponent digits even though the exponent
may grow up to 308. Before this change, printf("%g", 1e300) would
produce "1e+N0".

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
f286eda6f0 prf.c: remove arbitrary large stack buffer usage
The on-stack work buffer occupies 201 bytes by default. Now that we've
made the code able to cope with virtually unlimited width and precision
values, we can reduce stack usage to its strict minimum i.e. 25 bytes.

This allows for some additional sprintf tests exercizing wide results.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
d28434b4fa prf.c: remove buffer limitation on precision and padding for floats
Even if the code used to limit the precision to the on-stack buffer
size, it was still possible to do:

    printf("%f", 1.0e300);

which would overflow the stack and crash the program. Let fix this issue
and remove the precision limitation by recording the number of zeroes to
insert while converting the value and generating those zeroes only
when outputting the data.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
7c7f107885 prf.c: remove buffer limitation on field width and padding for integers
Zero-padding of integers took place in the on-stack buffer before
justification. Let's perform that padding on the fly while sending
out data instead.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
33312cfd98 prf.c: remove buffer limitation on field width and string copy
The z_prf() function currently allocates a 200-byte buffer on the
stack to copy strings into, and then perform left/right alignment
and padding. Not only this is a pretty large chunk of stack usage,
but this imposes limitations on field width and string length. Also
the string is copied not only once but _thrice_ making this code
less than optimal.

Let's rework the code to get rid of both the field width limit and
string length limit, as well as the two extra memory copy instances.

While at it, let's fixes printf("%08s", "abcd") which used to
produce "0000abcd".

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
4ad2a8f990 prf.c: don't be silent with unknown conversion specifiers
Mimic the glibc behavior when encountering an unknown conversion
specifier rather than silently skipping it.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
ab59209ea6 prf.c: abstract output method call
This makes for nicer code by avoiding repetitions of the same pattern.
Changes to come will make more use of it.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
e1d8c1f8ca prf.c: implement the "hh" length modifier
For completeness.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
e9b1cc5f31 prf.c: code and style cleanup
Some cleanups before further changes:

- Remove dead leftover from the "case 's'" code.

- Remove needless parents and casts.

- Remove "register" qualifier as it is ignored. The compiler knows
  better these days.

- Adjust tabs assuming standard 8-columns tab spacing.

- Make multi-line comments start with "/*" on a line of its own.

- Make the format string const to match  prototypes in other files.

- Declare boolean variable and parameters as bool.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-14 23:07:44 -04:00
Nicolas Pitre
ff7e4e69c8 realloc(): fix possible memory leak
If size is equal to zero, and ptr is not NULL, then the call must be
equivalent to free(ptr).

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-12 14:08:02 -07:00
Nicolas Pitre
ffab197928 libc: fix memchr() prototype
The standard memchr() uses an int for its second argument.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-10 13:42:31 -07:00
Timo Teräs
55dc481a15 libc: add strnlen implementation
This is standard function and useful for application writers.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
2019-07-10 13:41:20 -07:00
Jukka Rissanen
b889120ca7 Revert "libc: types: Remove wrong definition"
This reverts commit 2a63e342f4.

This needs to be reverted as otherwise the type of ssize_t will be
"unsigned long" which is not correct.

    (gdb) ptype ssize_t
    type = unsigned long

For example this check would fail in that case

    ssize_t foo(void)
    {
        return -1;
    }
    ...
    if (foo() < 0) {
        printk("This is never called\n");
    }

Fixes #17378

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
2019-07-09 21:55:05 +03:00
Nicolas Pitre
1b359e6426 limits.h: streamline value definitions
Compilers (at least gcc and clang) already provide max value definitions
for basic types. It makes sense to rely on them to properly support
both 32-bit and 64-bit builds.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-05 10:05:37 -04:00
Nicolas Pitre
cf974371fb mempool: make alignment/rounding 64-bit compatible
Minimum alignment and rounding must be done on a word boundary. Let's
replace _ALIGN4() with WB_UP() which is equivalent on 32-bit targets,
and 64-bit aware.

Also enforce a minimal alignment on the memory pool. This is making
a difference mostly on64-bit targets where the widely used 4-byte
alignment is not sufficient.

The _ALIGN4() macro has no users left so it is removed.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-02 19:41:20 -07:00
Anas Nashif
a2fd7d70ec cleanup: include/: move misc/util.h to sys/util.h
move misc/util.h to sys/util.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00
Anas Nashif
08ee8b09ba cleanup: include/: move misc/mempool.h to sys/mempool.h
move misc/mempool.h to sys/mempool.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00
Anas Nashif
6ecadb03ab cleanup: include/: move misc/math_extras.h to sys/math_extras.h
move misc/math_extras.h to sys/math_extras.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00
Anas Nashif
447311ec3e cleanup: include/: move misc/libc-hooks.h to sys/libc-hooks.h
move misc/libc-hooks.h to sys/libc-hooks.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00
Anas Nashif
896b8d3c50 cleanup: include/: move misc/errno_private.h to sys/errno_private.h
move misc/errno_private.h to sys/errno_private.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00
Anas Nashif
5eb90ec169 cleanup: include/: move misc/__assert.h to sys/__assert.h
move misc/__assert.h to sys/__assert.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00
Flavio Ceolin
2a63e342f4 libc: types: Remove wrong definition
types.h was wrongly defining unsigned as signed and following
undefining it. This definition was not being used anywhere though.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2019-06-27 07:17:04 -04:00
Nicolas Pitre
f32330b22c stdint.h: streamline type definitions
Compilers (at least gcc and clang) already provide definitions to
create standard types and their range. For example, __INT16_TYPE__ is
normally defined as a short to be used with the int16_t typedef, and
__INT16_MAX__ is defined as 32767. So it makes sense to rely on them
rather than hardcoding our own, especially for the fast types where
the compiler itself knows what basic type is best.

Using compiler provided definitions makes even more sense when dealing
with 64-bit targets where some types such as intptr_t and size_t must
have a different size and range. Those definitions are then adjusted
by the compiler directly.

However there are two cases for which we should override those
definitions:

* The __INT32_TYPE__ definition on 32-bit targets vary between an int
  and a long int depending on the architecture and configuration.
  Notably, all compilers shipped with the Zephyr SDK, except for the
  i586-zephyr-elfiamcu variant, define __INT32_TYPE__ to a long int.
  Whereas, all Linux configurations for gcc, both 32-bit and 64-bit,
  always define __INT32_TYPE__ as an int. Having variability here is
  not welcome as pointers to a long int and to an int are not deemed
  compatible by the compiler, and printing an int32_t defined with a
  long using %d makes the compiler to complain, even if they're the
  same size on 32-bit targets. Given that an int is always 32 bits
  on all targets we might care about, and given that Zephyr hardcoded
  int32_t to an int before, then we just redefine __INT32_TYPE__ and
  derrivatives to an int to keep the peace in the code.

* The confusion also exists with __INTPTR_TYPE__. Looking again at the
  Zephyr SDK, it is defined as an int, even even when __INT32_TYPE__ is
  initially a long int. One notable exception is i586-zephyr-elf where
  __INTPTR_TYPE__ is a long int even when using -m32. On 64-bit targets
  this is always a long int. So let's redefine __INTPTR_TYPE__ to always
  be a long int on Zephyr which simplifies the code, works for both
  32-bit and 64-bit targets, and mimics what the Linux kernel does.
  Only a few print format strings needed adjustment.

In those two cases, there is a safeguard to ensure the type we're
enforcing has the right size and fail the build otherwise.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-06-25 23:29:22 -04:00