Doxygen: Use mathjax

[MatzeB]

Summary

Does anyone have experiences (or objections) to this settings change?

The main motivation is to not require a latex installation when building the documentation. I would also expect a better image quality and the ability to copy&paste from formulas with a javascript based solution for displaying the math.

[silvas]

I haven't used the option before, but using mathjax seems like a win.
Do you have a particular page of our doxygen that you are looking at where
we use math?

Anyway, give it a shot and we can always roll back if it is undesirable.

Adding Hans just as an FYI, since IIRC he was generating the doxygen for
the release and may want to be aware of what is happening here in case it
causes some issue.

• Sean Silva

[hans]

I didn't know I needed LaTeX to build the docs before (though I have it installed, so I might not have noticed). I'm also curious to know where we use this in the doxygen.

Anyway, the change seems fine to me.

[MatzeB]

In D14960#296285, @silvas wrote:

I haven't used the option before, but using mathjax seems like a win.
Do you have a particular page of our doxygen that you are looking at where
we use math?

Anyway, give it a shot and we can always roll back if it is undesirable.

Adding Hans just as an FYI, since IIRC he was generating the doxygen for
the release and may want to be aware of what is happening here in case it
causes some issue.

• Sean Silva

At least our jenkins documentation builder is spewing errors about missing latex. I found out after creating this patch that these errors are non-fatal (and the root cause for failing jenkins bot was something else).

Anyway as far as I can see the only place where we have a formula is in llvm/ADT/DAGDeltaAlgorithm.h, I'll give the mathjax variant a go and see how it goes.

docs/doxygen.cfg.in

 # http://www.mathjax.org) which uses client side Javascript for the rendering
 # instead of using prerendered bitmaps. Use this if you do not have LaTeX
 # installed or if you want to formulas look prettier in the HTML output. When
 # enabled you may also need to install MathJax separately and configure the path
 # to it using the MATHJAX_RELPATH option.
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-USE_MATHJAX            = NO
+USE_MATHJAX            = YES
 
 # When MathJax is enabled you can set the default output format to be used for
 # the MathJax output. See the MathJax site (see:
 # http://docs.mathjax.org/en/latest/output.html) for more details.
 # Possible values are: HTML-CSS (which is slower, but has the best
 # compatibility), NativeMML (i.e. MathML) and SVG.
 # The default value is: HTML-CSS.
 # This tag requires that the tag USE_MATHJAX is set to YES.