* Output `GEN` log for generated files
* `MRBC` log is outputted one for each `mrbc` execution
#### Before this patch:
```console
CC src/array.c -> build/host/src/array.o
(snip)
GEN mrblib/*.rb -> build/host/mrblib/mrblib.c
MRBC mrblib/00class.rb
MRBC mrblib/10error.rb
(snip)
CC mrbgems/mruby-time/src/time.c -> build/host/mrbgems/mruby-time/src/time.o
MRBC mrbgems/mruby-time/mrblib/time.rb
(snip)
CC mrbgems/mruby-socket/test/sockettest.c -> build/host/mrbgems/mruby-socket/test/sockettest.o
MRBC mrbgems/mruby-socket/test/addrinfo.rb
MRBC mrbgems/mruby-socket/test/basicsocket.rb
(snip)
```
#### After this patch:
```console
GEN build/presym
GEN build/presym.inc
CC src/array.c -> build/host/src/array.o
(snip)
GEN mrblib/*.rb -> build/host/mrblib/mrblib.c
MRBC mrblib/00class.rb
mrblib/10error.rb
(snip)
CC mrbgems/mruby-time/src/time.c -> build/host/mrbgems/mruby-time/src/time.o
GEN build/host/mrbgems/mruby-time/gem_init.c
MRBC mrbgems/mruby-time/mrblib/time.rb
(snip)
CC mrbgems/mruby-socket/test/sockettest.c -> build/host/mrbgems/mruby-socket/test/sockettest.o
GEN build/host/mrbgems/mruby-socket/gem_test.c
MRBC mrbgems/mruby-socket/test/addrinfo.rb
MRBC mrbgems/mruby-socket/test/basicsocket.rb
(snip)
```
ref: https://github.com/mruby/mruby/pull/4959#discussion_r402086196
Compiles twice because it falls back to `build.filename(command)` when
`command` fails. This process was added at 9968af4 to support `ccache gcc`
etc. At that time, it seems that it was necessary because
`build.filename(command)` quoted the whole `command`, but now it does not
quote, so we can just run `build.filename(command)`.
### Example
```console
$ echo 1 > src/a.c
$ rake -v
```
#### Before this patch:
```console
(snip)
gcc -std=gnu99 -g -O3 -Wall -Wundef -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wwrite-strings -I"/mruby/mruby/include" -MMD -o "/mruby/mruby/build/host/src/a.o" -c "/mruby/mruby/src/a.c"
/mruby/mruby/src/a.c:1:1: error: expected identifier or '('
1
^
1 error generated.
gcc -std=gnu99 -g -O3 -Wall -Wundef -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wwrite-strings -I"/mruby/mruby/include" -MMD -o "/mruby/mruby/build/host/src/a.o" -c "/mruby/mruby/src/a.c"
/mruby/mruby/src/a.c:1:1: error: expected identifier or '('
1
^
1 error generated.
rake aborted!
(snip)
```
#### After this patch:
```console
(snip)
gcc -std=gnu99 -g -O3 -Wall -Wundef -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wwrite-strings -I"/mruby/mruby/include" -MMD -o "/mruby/mruby/build/host/src/a.o" -c "/mruby/mruby/src/a.c"
/mruby/mruby/src/a.c:1:1: error: expected identifier or '('
1
^
1 error generated.
rake aborted!
(snip)
```
Files under `test/t` and `mrbgem/*/test` are for tests, not for actual
execution. So symbols in those files need not to be pre-allocated. This
change slightly reduce the memory consumption.
Before this commit:
$ rake
...
$ rm build/host/src/gc.o
$ rake
rake aborted!
Don't know how to build task '/home/foo/mruby/build/host/src/gc.o' (See the list of available tasks with `rake --tasks`)
...
After this commit:
$ rake
...
$ rm build/host/src/gc.o
$ rake
CC src/gc.c -> build/host/src/gc.o
...
With gcc 9.3.0 on Ubuntu 20.04, build/host/src/array.d looks like:
/build/host/src/array.o: /src/array.c \
/include/mruby.h /include/mrbconf.h \
/include/mruby/common.h \
...
/include/mruby/range.h \
/src/value_array.h
and it has been parsed to:
[
# /src/array.c missing
"/include/mruby.h /include/mrbconf.h", # incorrectly parsed
"/include/mruby/common.h",
...
"/src/value_array.h",
]
After this change, *.d will be parsed correctly.
[
"/src/array.c",
"/include/mruby.h",
"/include/mrbconf.h",
"/include/mruby/common.h",
...
"/src/value_array.h",
]
If $rake_root_fiber is used, sh runs command in another Fiber. If
command is ran in another Fiber, "rescue RuntimEerror" can't rescue
exception for system(...) failure.
How to reproduce:
$ CC="gcc -std=gnu99" ./minirake
(in /home/kou/work/ruby/mruby.kou)
CC mrbgems/mruby-compiler/core/codegen.c -> build/test/mrbgems/mruby-compiler/core/codegen.o
sh: 1: gcc -std=gnu99: not found
rake aborted!
Command Failed: ["gcc -std=gnu99" -g -std=gnu99 ...]
KOBAYASHI Shuji