The `REnv` object is difficult to deal with, and it would be ideal if the user did not have to manipulate it directly.
In some previous situations, it was necessary to call `mrb_env_unshare()`, a non-API function, after `mrb_load_string()` or similar.
With this patch, it is no longer necessary for users to use `mrb_env_unshare()` directly, as it is now handled internally simply by using the `mrb_vm_ci_env_clear()` function.
Also, `mrb_vm_ci_env_set()` is demoted from the `MRB_API` function for the same reason.
ref. commit 1ab3da6f08
Exception raising can now be controlled by the caller.
The main purpose on this patch is:
- Suppress exceptions from `obj_free()` in `src/gc.c` with `mrb_env_unshare()`.
- Consider the possibility that calls to `mrb_malloc()` may cause `e` objects to be subject to GC.
When control is returned to `mrb_env_unshare()`, `struct free_obj::next` in the same offset as `struct REnv::stack` is rewritten.
Unexpected results then occur when the object is reused.
Also, if `mrb_heap_page` containing an `e` object is freed, it may cause `SIGSEGV` at that point.
- Protects the value of the stack on `callinfo` that just exits if GC occurs inside `mrb_env_unshare()`.
```ruby
def m
b = -> { b }
end
p m.call
# => print block object, not nil
```
This patch does not raise a `NoMemoryError` exception in `mrb_env_unshare()` and can detect that error.
Thus, the problem fixed in # 3087 is not resurrected.
Also, it may seem that this patch should suppress exceptions raised by `cipop()` during `mrb_protect_error()` and `mrb_vm_exec()` unwinds.
However, `mrb_callinfo::u.env` by `CINFO_DIRECT` is not seen to be set.
So in that case `mrb_env_unshare()` is assumed to be originally exception-free.
It is not decides by the extension.
In order to be recognized as a `.mrb` file, the following three points must be satisfied:
- File starts with "RITE"
- At least `sizeof(struct rite_binary_header)` bytes can be read
- `NUL` is included in the first 64 bytes of the file
If these are not met, it is judged as a text file and it is processed as a Ruby script.
The `bin/mruby -b` switch is still available which treats the given file as a `.mrb` file.
New `MRB_API` function:
- `include/mruby/compile.h` and `mrbgems/mruby-compiler/core/parse.y`
- `mrb_load_detect_file_cxt()` (remove with `MRB_DISABLE_STDIO`)
NOTE:
- Even script files now always open in binary mode for `bin/mruby`.
The `\r\n` is handled by the `nextc()` function already, so there is no problem even on Windows.
- The `nextc0()` function in `mrbgems/mruby-compiler/core/parse.y` can now specify a string buffer and a file pointer at the same time.
In this case, get it from the string buffer first.
This patch includes modifies by comment of https://github.com/mruby/mruby/pull/5157.
In addition, update the documents referring `build_config.rb` which is
no longer used. The new `build_config.rb` describes the new configuration
structure in the comment.
#### Before this patch:
```
$ bin/mruby -e 'p ARGV' a b
["bin/mruby", "-e", "p ARGV", "a", "b"]
```
#### After this patch:
```
$ bin/mruby -e 'p ARGV' a b
["a", "b"]
```
No need to optimize since a program only exits once and errors are rare.
Also the mruby source code doesn't have these kind of checks elsewhere.
The ones in {Time,Random}#initialize are kept because there it actually
matters
since initialization always happens and re-initialization is unlikely.
Here are suppressed warnings:
src/fmt_fp.c: In function 'fmt_fp':
src/fmt_fp.c:124:16: warning: initialization discards 'const' qualifier from pointer target type
char *ss = (t&32)?"inf":"INF";
^
src/fmt_fp.c:125:17: warning: assignment discards 'const' qualifier from pointer target type
if (y!=y) ss=(t&32)?"nan":"NAN";
^
mrbgems/mruby-string-ext/src/string.c: In function 'mrb_str_succ_bang':
mrbgems/mruby-string-ext/src/string.c:302:27: warning: assignment discards 'const' qualifier from pointer target type
if (e == b) prepend = "1";
^
mrbgems/mruby-string-ext/src/string.c:305:27: warning: assignment discards 'const' qualifier from pointer target type
if (e == b) prepend = "a";
^
mrbgems/mruby-string-ext/src/string.c:308:27: warning: assignment discards 'const' qualifier from pointer target type
if (e == b) prepend = "A";
^
mrbgems/mruby-bin-mruby/tools/mruby/mruby.c: In function 'main':
mrbgems/mruby-bin-mruby/tools/mruby/mruby.c:213:13: warning: assignment discards 'const' qualifier from pointer target type
cmdline = args.cmdline ? args.cmdline : "-";
^
mrbgems/mruby-bin-debugger/tools/mrdb/cmdbreak.c: In function 'print_breakpoint':
mrbgems/mruby-bin-debugger/tools/mrdb/cmdbreak.c:159:3: warning: initialization discards 'const' qualifier from pointer target type
char* enable_letter[] = {BREAK_INFO_MSG_DISABLE, BREAK_INFO_MSG_ENABLE};
^
mrbgems/mruby-bin-debugger/tools/mrdb/cmdbreak.c:159:3: warning: initialization discards 'const' qualifier from pointer target type
John Bampton