Bug 24107 – The error for exceeding the CTFE recursion limit bypasses speculative compilation.

Exceeding the CTFE recursion limit (which is one-thousand recursive calls) causes the compiler to emit an error. The issue is that this error is emitted even when the compiler is compiling speculatively, such as when evaluating an argument for `__traits(compiles, ...)`. This code will replicate the issue: > bool recurse () > { > return recurse(); > } > > pragma(msg, "This should not output an error message: ", __traits(compiles, {enum bool r = recurse();})); which outputs: > This should not output an error message: .\ctfeRecursionError.d(1): Error: function `ctfeRecursionError.recurse` CTFE recursion limit exceeded > .\ctfeRecursionError.d(3): called from here: `recurse()` > .\ctfeRecursionError.d(1): 1000 recursive calls to function `recurse` > .\ctfeRecursionError.d(6): called from here: `recurse()` > false when it should output: > This should not output an error message: false The offending bit of code, in the compiler, that causes this seems to be in `dmd.dinterpret`, wherein `global.gag` is set to zero: https://github.com/dlang/dmd/blob/0b937d671023a1bf86985b2452096a64aae85f07/compiler/src/dmd/dinterpret.d#L638

@RazvanN7 created dlang/dmd pull request #15587 "Fix Issue 24107 - The error for exceeding the CTFE recursion limit by passes speculative compilation." fixing this issue: - Fix Issue 24107 - The error for exceeding the CTFE recursion limit bypasses speculative compilation. https://github.com/dlang/dmd/pull/15587

dlang/dmd pull request #15587 "Fix Issue 24107 - The error for exceeding the CTFE recursion limit by passes speculative compilation." was merged into master: - 44ddc26d1a3ced47636f54280380db1ef3189a7a by RazvanN7: Fix Issue 24107 - The error for exceeding the CTFE recursion limit bypasses speculative compilation. https://github.com/dlang/dmd/pull/15587