[Issue 24505] New: [REG2.108] ImportC: Function-like macros (newly translated to templates) may collide with regular symbols

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=24505

          Issue ID: 24505
           Summary: [REG2.108] ImportC: Function-like macros (newly
                    translated to templates) may collide with regular
                    symbols
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: kinke at gmx.net

This is a snippet derived from a Windows-specific Postgres header, which cannot
be imported with DMD v2.108 anymore:
```
struct stat { int x; };

void __stat(int x, int y);
#define stat(x, y) __stat(x, y)
```

```
Error: template `c.stat(__MP21, __MP22)(__MP21 x, __MP22 y)` conflicts with
struct `c.stat` at c.c(1)
```

I think it'd be better to skip the new macro-translation in such a case, maybe
with a printed warning. Alternatively, some ugly escape hatch via e.g.
`--ignore-macro=stat` - patching C headers isn't really a feasible option.

--