VBA Conditional Compilation Grammar

[Beakerboy]

VBA includes a precompiler of sorts, with its own grammar. The existing vba6 grammar tries to shoehorn it in with the main language, but there are situations where a VBA file with CC statements is not valid VBA until after the precompiler is run.
For example:

#If WIN64 Then
Function Foo(bar, Optional baz = 1)
#Else
Function Foo(bar, Optional baz = 2)
#End If
End Function

This new grammar powers a precompiler which can turn this example into valid VBA given a set of environment variables.

[Beakerboy]

I see that there is a failure in only one of the build matricies. I’m more than happy to fix this if someone can tell me what it means.

[kaby76]

The problem is that there are symbol conflicts: EMPTY, WIN16, WIN32, WIN64. In your grammar .g4 file, append an underscore (_) to the end of these symbols, then check-in and retest.

Please enter a bug in https://github.com/antlr/antlr4/issues saying that for the Cpp target, EMPTY, WIN16, WIN32, WIN64 are known conflicts, like because there are #defines somewhere for Visual C++. The implementation for resolving symbol conflict is not reliable, and there is a long lack time between finding a symbol conflict and then releasing a new version of the Antlr Tool to take care of the issue--if there are anymore Antlr4 releases! There should be an option to append or prepend a string to all names in the generated files, so we don't need to keep adjusting the table for "known" symbol conflicts, or manually adjusting the grammar to workaround the problem.

[Beakerboy]

I’ve removed that target. I can re-add it in a a few days when I add the VBA 7.1 grammar.

[Beakerboy]

Renamed tokens after the ninja edit and re-added the CPP target. Good to go.

[Beakerboy]

In case you were waiting for this..I also filed the big report as requested:
antlr/antlr4#4641

[teverett]

@Beakerboy thanks!