ref #3215
If a function (such as mrb_read_irep_file()) is declared without MRB_API
in header file (such as include/mruby/dump.h), implementation of the
function in source file (such as src/load.c) should also defined without
MRB_API.
If MRB_API is mismatch, Visual C++ reports link error with C2375 error
code: https://msdn.microsoft.com/en-us/library/5k6kw95a.aspx
GitHub: fix#2902, #2917
The current implementation traverses stack to retrieve backtrace. But
stack will be changed when some operations are occurred. It means that
backtrace may be broken after some operations.
This change (1) saves the minimum information to retrieve backtrace when
exception is raised and (2) restores backtrace from the minimum
information when backtrace is needed. It reduces overhead for creating
backtrace Ruby objects.
The space for the minimum information is reused by multiple
exceptions. So memory allocation isn't occurred for each exception.
Previously there wasn't a way to trigger the useful definition, but it
is needed and that in every case to check for integer overflow due to
multiplication and faulty/modified binary files.
Also change existing code to a calloc()-like parameter order.
It's only used once and in that case it isn't necessary anyway, since
size_t must be at least 32 bits wide and
the max. length of a filename is UINT16_MAX.
buf_size has to be greater than header_size, otherwise subtracting
header_size from buf_size will cause an integer underflow.
Being equal to header_size is fine, however useless, so quit early.
`mruby -b` now accepts both big/little endian mrb (compiled binary) files.
`mrbc` generates mrb files in big endian for .mrb files and in native endian
for C files (with -B option specified) by default. If you are cross compiling,
you need to specify target endian by -e/-E options if it is different from
host endian.
Add padding bytes before iseq block that may be used as mrb_code[].
Note that dumped mrb format has changed.
Based on a patch from kimu_shu <alfvegardrisc@gmail.com>
Yukihiro "Matz" Matsumoto