ADD linkbefore and linkafter option

[louxiu]

To have chance to add more linker options. #247

[saudet]

Allowing to set compiler options directly in the Java files makes it harder to set properties for multiple platforms. Also, it's just occurred to me that we can probably already use platform.link.prefix and platform.link.suffix to solve this issue cleaning, for example:

platform.link.prefix=-Wl,--whole-archive -l
platform.link.suffix= -Wl,--no-whole-archive

Should work if we update the Builder a bit to split the properties into multiple options at the white spaces, like it's already doing for platform.compiler. Could you give that a try?

[louxiu]

Sorry for late reply. It's a clever way. 😃 I resubmit a commit. And should we change the property file(linux-x86_64.properties etc) or there is another way to override the default value of platform.link.prefix and platform.link.suffix?

[saudet]

Yes, that's what the "properties" in the command line option and in the Mojo configuration are for. I wonder if we can make this the default though?

We want to merge the last prefix with the library name, but only when it doesn't end with a space, and similarly for the first suffix. Are you sure your changes do that?

[louxiu]

Ok, I know what's your preferred way. Please check it again.

[saudet]

No, that doesn't split all spaces. We can do like it was before, but consider the parts after the first "word" in the suffix as independent options, and similar for prefix.

[louxiu]

@saudet done

[saudet]

Looking better, almost there, but with the following properties when there are no libraries to link (like with the unit tests that you can try by running mvn test) it appends a -Wl,--whole-archive without a -Wl,--no-whole-archive. Moreover, when we do specify a library to link, the suffix gets appended to the library name like -lfoo-Wl,--no-whole-archive, when that should be 2 separate options.

platform.link.prefix=-Wl,--whole-archive -l
platform.link.suffix= -Wl,--no-whole-archive

[louxiu]

@saudet I know the problem. Space before link suffix in properties should be \u0020
platform.link.prefix=-Wl,--whole-archive -l
platform.link.suffix=\u0020-Wl,--no-whole-archive

And I modified the code, ignore link before and after options if there is no lib links

[saudet]

Ah, yes, good catch! That makes it a bit harder to use, but oh well. Using a backslash to escape like this also works:

platform.link.prefix=-Wl,--whole-archive -l
platform.link.suffix=\ -Wl,--no-whole-archive

Anyway, now it looks like the whole prefix gets appended to the library name in only 1 option, including the space, like this: g++ ... '-Wl,--whole-archive -lfoo' .... Those need to be 2 options.

[louxiu]

No, if I test correctly. The latest commit has splitted -Wl,--whole-archive -l as 2 options.

[saudet]

You're right, I was testing on the wrong branch, sorry. Seems to work correctly, but it's stripping the options in between each library. I'm not sure it always makes sense to do that? It wouldn't hurt to leave them at least... What do you think?

[louxiu]

I think I got what you mean finally.
It should be

-Wl,--xxx -Wl,--whole-archive -lfoo -Wl,--no-whole-archive -Wl,--whole-archive -lbar -Wl,--no-whole-archive 👍
-Wl,--xxx -Wl,--whole-archive -lfoo -lbar -Wl,--no-whole-archive 👎
'-Wl,--xxx -Wl,--whole-archive' -lfoo -Wl,--no-whole-archive '-Wl,--xxx -Wl,--whole-archive' -lbar -Wl,--no-whole-archive 👎

Sorry for my bad English. Is it right?

[saudet]

I think that would be best, yes, but do you think that's OK?

[saudet]

It would actually be like this though:

-Wl,--xxx -Wl,--whole-archive -lfoo -Wl,--no-whole-archive -Wl,--xxx -Wl,--whole-archive -lbar -Wl,--no-whole-archive

[louxiu]

Yes, I prefer that way too. It keeps meaning of link.prefix and link.suffix. I misunderstand your comment. 😢

We want to merge the last prefix with the library name, but only when it doesn't end with a space, and similarly for the first suffix.