Relative property location is invalid when building in top-level dirs on linux

[layus]

Trying to build lwjgl on linux failed for me because src.main.rel was improperly set to ../../modules/opengl/[...] when it was supposed to be ../../../../modules/opengl/[...] where the four .. come from

lwjgl3/config/linux/build.xml

Line 20 in 015c9a9

<property name="module.lwjgl.rel" value="../../../../${module.lwjgl}"/>

This happens because src.main.rel is set with a relative property location in

lwjgl3/config/linux/build.xml

Line 79 in 015c9a9

<property name="src.main.rel" location="${module.lwjgl.rel}/@{module}/src/main/c" relative="true"/>

and finally used after going two directories deeper (@{dest}) at

lwjgl3/config/linux/build.xml

Line 52 in 015c9a9

<arg value="-I${src.main.rel}" if:true="@{simple}"/>

Now, if you happen to build in /build/lwjgl-xxx/, the relative path will be truncated (because in /build/lwjgl-xxx/ ../../../.. is the same as ../.. so some kind of canonicalization occurs.)

Proposed solution in this PR. Tested and working by only changing src.main.rel. This PR is more a POC than something to be merged as-is.

[Spasi]

Hey @layus,

I'm not sure what this means:

if you happen to build in /build/lwjgl-xxx/, the relative path will be truncated

The Ant build is meant to be executed from the repository root. What are you doing differently exactly?

[layus]

What I am saying is that building from the repository root, when that repository root is not deep enough in the filesystem tree, fails.

For example, assuming the repository root is in a dir named lwjgl-xxx, building with the repository root in /home/user/projects/lwjgl-xxx will work, and building in /build/lwjgl-xxx will not. Most probably, building in /lwjgl-xxx or /var/test/lwjgl-xxx will not. The build is somehow dependent of the (filesystem) depth where the checkout is made.

I of course always start the build in the checkout root.

[layus]

Or said differently, that the ../../../.. in module.lwjgl.rel was meant to be used in a different cwd than where it is defined. It was not ported correctly in the build system refactoring and was not intended to be used in a <property name="..." location="..." relative="true"/>

[Spasi]

Thank you @layus!