Exceptions on Windows being "swallowed"

[Rainer Schuetze]

On 27/11/2019 06:55, cartland wrote:
> On Wednesday, 27 November 2019 at 05:43:33 UTC, Mike Parker wrote:
>> On Wednesday, 27 November 2019 at 05:15:10 UTC, cartland wrote:
>> *snip*
>>
>> dmd -m32mscoff -debug -g x.d
>>
>> And see what happens.
> 
> No difference between "dmd -m32mscoff -debug -g x.d" and "dmd -m32mscoff
> x.d"
> 
> --------
> C:\tmp\x>dmd -m32mscoff -debug -g x.d
> 
> C:\tmp\x>x
> hello
> 
> C:\tmp\x>dmd x.d
> 
> C:\tmp\x>x
> hello
> finally
> catch first
> done
> ----------
> 
> x.d contents
> --------
> import std.stdio;
> void main() {
>     writeln("hello");
>     try {
>         try {
>             throw new Exception("first");
>         } finally{
>             writeln("finally");
>             throw new Exception("second");
>         }
>     } catch (Exception e) {
>         writeln("catch ", e.msg);
>     }
>     writeln("done");
> }
> -----------
> 

In a debugger, I get:

Unhandled exception at 0x004010EF in x.exe: 0xC00001A5: An invalid
exception handler routine has been detected (parameters: 0x00000001).

This seems to happen when lld is used instead of the Microsoft linker.

Maybe related: https://bugs.llvm.org/show_bug.cgi?id=42221

Using lld from LLVM 9 spits out errors "not compatible with SEH", but
links using /SAFESEH:NO. The resulting executable then works.

I have created an issue: https://issues.dlang.org/show_bug.cgi?id=20421