Fix the following build warning
Compile [ 83.4%]: mbed_error.c
[Warning] mbed_error.c@71,21: 'compute_crc32' defined but not used [-Wunused-function]
compute_crc32 usage is guraded with #define, but not the definition.
Use the same #define around the definition of compute_crc32()
The pre-main check of error_reboot_count was applied repeatedly on
every boot, meaning that once the reboot limit was hit, every subsequent
reset would halt before main, until something managed to clear
or corrupt the error context.
Set the is_error_processed flag before halting, so that when an external
agent resets us while we're halted, we do not report the error and halt
again.
Save some ROM space by putting MBED_NORETURN attributes on error
functions and failed asserts.
mbed_error was documented as returning an error code. It never
actually could return, so documentation updated, but return type
kept.
Various fixes in preparation for making sure error calls do not return.
* Clear out handle_error's use of error_in_progress as a sort of spin
lock; this is most likely to deadlock if ever activated, and conflicts
with error's use of error_in_progress. Use a normal critical section lock.
* Make error use same mbed_halt_system helper as mbed_error.
* Make error's recursion check avoid print and proceed to halt, rather
than returning.
* Make mbed_error use error_in_progress to avoid recursion in same way
as error() does.
* Give mbed_halt_system its own recursion check in case of error in
mbed_die - give it a simple fallback.
* Make the in_progress things properly atomic, just in case.
Don't extract filename from the stored error - print it directly.
Use "mbed_error_puts" for both error message and filename to avoid
buffer length limits.
Switch to puts also fixes the potential problem of an error message
containing a '%' upsetting the formatter - it should have been
mbed_printf_error("%s", error_msg) in the first place.
Code had mixed up order of 'c' and 'n' arguments to memset().
Fix this.
Spotted-by: kjbracey-arm & a GCC profile without "-fno-builtin"
Related GCC warnings:
---8<---8<----
[Warning] mbed_error.c@123,5: 'memset' used with constant zero length parameter; this could be due to transposed parameters [-Wmemset-transposed-args]
[Warning] mbed_error.c@282,5: 'memset' used with constant zero length parameter; this could be due to transposed parameters [-Wmemset-transposed-args]
`handle_error` calls `MBED_CALLER_ADDR()`, but this is always a location from within platform/mbed_error.c. This is because `handle_error` is declared static. This does not cause the function to be inlined however. Instead, it is called by each function within mbed_error.c. For example, mbed_error yields this code:
```
000625c8 <mbed_error>:
625c8: b510 push {r4, lr}
625ca: 460c mov r4, r1
625cc: 4611 mov r1, r2
625ce: 461a mov r2, r3
625d0: 9b02 ldr r3, [sp, #8]
625d2: f7ff feff bl 623d4 <handle_error>
625d6: b968 cbnz r0, 625f4 <mbed_error+0x2c>
625d8: 4620 mov r0, r4
625da: f7ff ff67 bl 624ac <print_error_report.constprop.0>
625de: f7ff fea8 bl 62332 <core_util_is_isr_active>
625e2: b910 cbnz r0, 625ea <mbed_error+0x22>
625e4: f7ff fe9f bl 62326 <core_util_are_interrupts_enabled>
625e8: b908 cbnz r0, 625ee <mbed_error+0x26>
625ea: bf30 wfi
625ec: e7fd b.n 625ea <mbed_error+0x22>
625ee: 2001 movs r0, #1
625f0: f000 f948 bl 62884 <__wrap_exit>
625f4: 4800 ldr r0, [pc, #0] ; (625f8 <mbed_error+0x30>)
625f6: bd10 pop {r4, pc}
625f8: 80ff010f .word 0x80ff010f
```
Note that at `625d2` there is a bl to handle error. That replaces the LR, which means that ALL calls to mbed_error will report a location of 0x625d6 or 0x625d7 (user vs. supervisor). I do not expect that this was the intention of the code. The simplest fix is to change line 99:
```C
static inline mbed_error_status_t handle_error(mbed_error_status_t error_status, unsigned int error_value, const char *filename, int line_number)
```
Since `handle_error()` will be inlined, the link register will be kept the same, so `MBED_CALLER_ADDR()` will yield the expected result. However, there is no guarantee that the compiler will respect the `inline` keyword in all circumstances.
The result is that each function that wishes to report its caller must extract its caller. This code cannot be centralised.
I have modified `mbed_error.c` to report the caller of each error reporting function, rather than the error reporting function itself.
The new configuration make Error history tracking switched off by default and enabled by using the config flag MBED_CONF_PLATFORM_ERROR_HIST_ENABLED.
Config flag MBED_CONF_PLATFORM_ERROR_ALL_THREADS_INFO enables printing info of all threads. This will be turned off by default.
Naveen Kaje
Kevin Bracey
Senthil Ramakrishnan
Martin Kojtal
MateuszMaz
Tero Jääskö
Brendan Moran
Russ Butler
Christopher Haster
Sam Grove