LLVM in the IDE

This page describes what the IDE shows when a project is compiled with LLVM: where the options are, the licence banners, the progress box and the cache. What LLVM is, which options to choose and what the LLVM compiler does not support are in Getting Started with LLVM.

Where the options are

The options are in two sections of Project Settings: Compiler Options (BUILD) and Compiler Options (DEBUG). Each has a tick box, Enable LLVM Compilation, two for optimization and one for each CPU feature.

  • Build compiles with the BUILD options. The file that it writes is the one compiled with LLVM.
  • Start (F5) runs the project with the DEBUG options. The IDE cannot debug code that LLVM compiled, so the description of this section advises against turning LLVM on there.

The IDE has no Build with LLVM button. Both sections are empty in a new project.

The IDE Options has three more, which belong to the compiler and its cache and are not part of any project: the number of threads, the threshold for reporting a complex procedure, and whether the cache process stays alive after the IDE closes. A change to any of them restarts the compiler. See Compiler and LLVM.

The licence banners

LLVM compilation depends on the licence. When the settings dialog is drawn, each of the two sections shows a banner next to the licence badge, if the licence limits it:

  • With a Personal licence, the banner says that the optimizations apply only to the built-in packages (VB, VBA, VBRUN) and not to your own code, and advises an upgrade to a Professional licence.
  • With a Community licence, the banner says that the optimizations are not applied, and advises an upgrade to a paid licence.
  • With a Professional or Ultimate licence there is no banner.

The banner follows the licence badge at the moment the dialog opens. Getting Started with LLVM says what each edition gets.

The progress box

When the compiler reports progress, the IDE opens a box titled Compiling… with a bar, and the compiler can also fill an item of the status bar with the percentage, such as LLVM: n%. The box is modal: the IDE cannot be used until it closes, and it closes by itself when the build ends. Which builds report progress is the compiler’s choice. A small project compiled with LLVM takes a fraction of a second, so the box is gone almost at once.

Note BETA 1010

If another box opens while Compiling… is on screen, the end of the build closes that box instead of the progress box, so the other box is lost. The Compiling… box stays, with no button, and the IDE cannot be used. Restart the IDE.

The cache

The compiler keeps a cache of LLVM code, in a process of its own, so that a later build is faster. Tools → Flush the LLVM compiler cache ends that process and restarts the compiler from the project in memory, as the console says with restarting from MEMORY. The next build compiles everything again and takes longer. Restart the compiler, with Alt held, restarts the cache process too.

See Also