Fix version with NULLPTR in JSON output

[wilzbach]

global._version has been changed at some point to an
null-terminated string. However, its type was still a D string. Some
parts of the code base were updated to do .length - 1, but other like
the compilerInfo were forgotten. This change remedies this and:

• removes manual null terminator addition from the D string of _version
• parses the versionNumber at compile-time
• exposes _version as versionString

CC @MoonlightSentinel

[dlang-bot]

Thanks for your pull request, @wilzbach!

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Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#11640"

[ibuclaw]

Headers.

[wilzbach]

Aren't enums only existent at CT and not passed to the layout?

[ibuclaw]

Aren't enums only existent at CT and not passed to the layout?

Yes. But there is still the field in the headers.

[wilzbach]

Fair enough. I set _version to private, removed it from the header and exposed it to C++ via versionString and added a small test to cxx-frontend. I hope that works for GDC?

[wilzbach]

Great, so there's https://issues.dlang.org/show_bug.cgi?id=21206 (and the entire mess of arrays/string interop with C++).
We really need to get #8120 in :/

Example:

extern(C++):

struct Foo {
  string s;   
}

void foo(Foo s) {} // OK
string foo() { return ""; } // OK on Posix, Error on Windows

void foo(string s) {} // error

https://run.dlang.io/is/FaSmWk

Generated header file:

// Automatically generated by Digital Mars D Compiler v2093

#pragma once

#include <stddef.h>
#include <stdint.h>


struct Foo;

struct Foo
{
    DArray< char > s;
    Foo() : s() {}
};

extern void foo(Foo s);

extern DArray< char > foo();

extern void foo(DArray< char > s);

https://run.dlang.io/is/lSm56k

[ibuclaw]

Could you make the extern(C++) function return a const char* instead? The only reason why a implementing compiler needs to have access to the version field is for:

message ("version   %s", global.version.ptr);

[wilzbach]

Could you make the extern(C++) function return a const char* instead? The only reason why a implementing compiler needs to have access to the version field is for:

Done.

[wilzbach]

Blocked by https://issues.dlang.org/show_bug.cgi?id=21217 -> #11679

[UplinkCoder]

do you plan to leave this hardcoded?

[wilzbach]

See my prior comment - https://issues.dlang.org/show_bug.cgi?id=21217 and #11679.

[wilzbach]

leave this hardcoded?

It's gone now ;-)