RTS header files can't be used with a C++ compiler (#14784) · Issues · Glasgow Haskell Compiler / GHC

RTS header files can't be used with a C++ compiler

If you compile m1.cpp:

#include "Rts.h"
int main(int argc, char** argv) {
}

with:

g++ -g m1.cpp -std=c++11 -I includes/ -c

you get:

In file included from includes/Rts.h:29:0,
                 from m1.cpp:1:
includes/Stg.h:29:3: error: #error __STDC_VERSION__ does not advertise C99 or later
 # error __STDC_VERSION__ does not advertise C99 or later
   ^

It's not advertised anywhere that it should work, but it used to work. https://phabricator.haskell.org/D2045 is what introduced this check.

Judging by https://stackoverflow.com/questions/48045243/ghc-gcc-compiler-issue-stdc-version-w-c99-from-stg-h-fails-for-every-packa, it affects GHC 8.2 and later.

Trac metadata

Trac field	Value
Version
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Runtime System
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	hvr, simonmar
Operating system
Architecture

If you compile `m1.cpp`:

```
#include "Rts.h"
int main(int argc, char** argv) {
}
```

with:

```
g++ -g m1.cpp -std=c++11 -I includes/ -c
```

you get:

```
In file included from includes/Rts.h:29:0,
                 from m1.cpp:1:
includes/Stg.h:29:3: error: #error __STDC_VERSION__ does not advertise C99 or later
 # error __STDC_VERSION__ does not advertise C99 or later
   ^
```

It's not advertised anywhere that it should work, but it used to work.
https://phabricator.haskell.org/D2045 is what introduced this check.

Judging by https://stackoverflow.com/questions/48045243/ghc-gcc-compiler-issue-stdc-version-w-c99-from-stg-h-fails-for-every-packa, it affects GHC 8.2 and later.

<details><summary>Trac metadata</summary>

| Trac field             | Value          |
| ---------------------- | -------------- |
| Version                |                |
| Type                   | Bug            |
| TypeOfFailure          | OtherFailure   |
| Priority               | normal         |
| Resolution             | Unresolved     |
| Component              | Runtime System |
| Test case              |                |
| Differential revisions |                |
| BlockedBy              |                |
| Related                |                |
| Blocking               |                |
| CC                     | hvr, simonmar  |
| Operating system       |                |
| Architecture           |                |

</details>