Building LLVM Doc(set)

LLVM has a large doc base which takes literally 12hours+ to build on my configuration. This post is a collection of techniques I found that could improve either the build doc size/build time/quality

Generic Changes

• Change VERBATIM_HEADERS and SOURCE_BROWSER to NO. This would remove embedded LLVM source, results in much smaller build size and shorter build time.
• Change STRIP_FROM_PATH to correct file-system folder base, this would fix some issues where absolute path is included in the product

Speedup Indexing

After generating the docs, you can generate Apple Docset, in which the indexing process would take more than 12hours normally. Edit the generated Makefile

• Clang: $(BUILD_ROOT)/tools/clang/docs/doxygen/html/Makefile
  
• LLVM: $(BUILD_ROOT)/docs/doxygen/html/Makefile

Change $(XCODE_INSTALL)/usr/bin/docsetutil index $(DOCSET_NAME) to $(XCODE_INSTALL)/usr/bin/docsetutil index -skip-text $(DOCSET_NAME) will decrease the indexing time to roughly an hour or so without negative impact as far as I know

Optional

• Change CREATE_SUBDIRS to YES
• Edit DOCSET_FEEDNAME DOCSET_BUNDLE_ID DOCSET_PUBLISHER_ID DOCSET_PUBLISHER_NAME if GENERATE_DOCSET is set to YES (Used for building Apple Docset
• Change DOT_IMAGE_FORMAT to svg and INTERACTIVE_SVG to YES, the former would use SVGs instead of PNGs, the latter would generate interactive,zoom-able inherit diagrams
• For Apple Docset users, refer to https://kapeli.com/docsets#doxygen for more specific instructions