On Friday, 13 April 2018 at 10:47:18 UTC, Rene Zwanenburg wrote:
On Friday, 13 April 2018 at 05:31:25 UTC, Jesse Phillips wrote:
Well if DIP1000 isn't on by default I don't think Phobos
should be compiled with it.
I think that the version issue is not unique to D and would be
good to address, but I don't see the compiler reading the
object file to determine how it should built the import files.
More importantly, it can be perfectly valid to link object
files compiled with different options. Things like parts of the
program that shouldn't be optimized, or have their logging
calls added/removed.
One thought I has was that we could define a special symbol that
basically encodes the configuration that was used to compile a
module. So when you import a precompiled module, you can insert
a dependency on that special symbol based on the configuration
you interpreted the imported module with with. So if a module is
compiled and imported with a different configuration, you'll get
a linker error.
If we take the previous example with main and foo.
compile foo with -version=FatFoo
foo.o contains special symbol (maybe
"__module_config_foo_version_FatFoo")
compile main without -version=FatFoo
main.o contains dependency on symbol "__module_config_foo" (note:
no "version_FatFoo")
link foo.o main.o
Error: symbol "__module_config_foo" needed by main.o is not
defined
The linker error isn't great, but it prevents potential runtime
errors. Also, if you use the compiler instead of the linker
you'll get a nice error message.
dmd foo.o main.o
Error: main.o expected module foo to be compiled without
-version=FatFoo but foo.o was compiled with it
