https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95198
Bug ID: 95198
Summary: [D] extern(C) private final functions should use
'local' linker attribute
Product: gcc
Version: 10.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: d
Assignee: ibuclaw at gdcproject dot org
Reporter: witold.baryluk+gcc at gmail dot com
Target Milestone: ---
```
module t1;
extern(C)
private final int f() {
return 5;
}
pragma(msg, f.mangleof);
```
`gdc -c t1.d -o t1.o` results in object with this symbols:
0000000000000000 D _D2t111__moduleRefZ
0000000000000000 D _D2t112__ModuleInfoZ
U _d_dso_registry
0000000000000000 T f
0000000000000000 W gdc.dso_ctor
0000000000000000 W gdc.dso_dtor
0000000000000000 u gdc.dso_initialized
0000000000000000 u gdc.dso_slot
0000000000000016 t _GLOBAL__D_2t1
000000000000000b t _GLOBAL__I_2t1
U _GLOBAL_OFFSET_TABLE_
U __start_minfo
U __stop_minfo
Symbol, '0000000000000000 T f' should instead be '0000000000000000 t f'
Additional when using optimizations, I would expect the f to not be emitted at
all, but it is still there (unless compiler decides not to inline it or its
address is not taken and passed around), even with `gdc -O3`.
gcc for C does use LOCAL for static functions and variables in translation
unit. Similarly probably for C++ symbols in anonymous namespaces.
Example of linking issues:
t1.d:
```
module t1;
extern(C)
private final int f() {
return 5;
}
```
t2.d:
```
module t2;
extern(C)
private final int f() {
return 10;
}
```
tm.d:
```
module tm;
void main() {
}
```
$ gdc -O0 -c t1.d -o t1.o
$ gdc -O0 -c t2.d -o t2.o
$ gdc t1.o t2.o tm.d -o t12
/usr/bin/ld: t2.o: in function `f':
t2.d:(.text+0x0): multiple definition of `f'; t1.o:t1.d:(.text+0x0): first
defined here
collect2: error: ld returned 1 exit status
$
This code should link, similar to equivalent code in C. The use case is local
function that is passed in some other module function or method (or static
module constructor for example), to C libraries or other modules as a callback
or for variables a return value.
