Support `noreturn` routine directive

[cirras]

Prerequisites

• This improvement has not already been suggested.
• This improvement would be generally useful, not specific to my code or setup.

Engine area

Delphi language support

Improvement description

Delphi 13 has introduced a new noreturn routine directive.

It indicates to the compiler that "the call is going to raise an exception and not complete regular execution."

Applying the noreturn directive tells the compiler that it can make some optimizations and skip some warnings at the callsite (like W1035) since regular execution will not continue after the call.

A good example of a noreturn routine is the OutOfMemoryError procedure in the standard library. It unconditionally raises a cached OutOfMemoryException.

We'll need to:

• parse the new syntax (noreturn token)
• extend the CFG to treat calls to noreturn routines like unconditional exception raises
• API: extend the RoutineDirective enum

See

• The noreturn Directive

Rationale

Delphi 13 support.

[Daniel-Tr]

We see quite a lot of errors like this when using SonarDelphi 1.18.2 with Delphi 13. Looking at the diff in System.SysUtils.pas, the most conspicious change is the use of "noreturn". That leads to the question: Do you already have an ETA on the Delphi 13 Milestone?

Error while processing C:\Program Files (x86)\Embarcadero\Studio\Current\source\rtl\sys\System.SysUtils.pas
au.com.integradev.delphi.file.DelphiFile$DelphiFileConstructionException: Failed to construct DelphiFile (line 394:19 no viable alternative at input '(')
at au.com.integradev.delphi.file.DelphiFile.setupFile(DelphiFile.java:163)
at au.com.integradev.delphi.file.DelphiFile.from(DelphiFile.java:137)

[cirras]

Thanks for letting us know that this is causing errors on Delphi 13.

We don't have an ETA on full Delphi 13 support, but will prioritise things like this that are actively breaking scans.

[Daniel-Tr]

I'm sorry should it feel impatient, but do you have an update on this issue (and eventually on support for Delphi 13 in general)? It's been some months already and all our SonarDelphi-scans are still broken, effectively hindering us from updating to Delphi 13.

[cirras]

We don't have an ETA on full Delphi 13 support (ternary expressions in particular will probably take a bit of time), but will aim to address this issue and other low-hanging fruit first when we have some free time available.

[darianmiller]

One workaround (if you don't use the new language features in your source) is to point the plugin to the Delphi 12 source (Make a copy of the /source folder from Delphi 12)