DMD 2.109.1 -betterC under Windows 10
The code below executes correctly:
extern (C) void main() {
import core.stdc.stdio : printf;
size_t wkIdx;
size_t wkPos;
enum Count = 1;
struct OpVar {
void* Addr;
int Type;
}
OpVar[Count] OpVars;
int IntVar1 = 5;
OpVars[0].Addr = &IntVar1;
OpVars[0].Type = 1;
for (wkPos = 1; wkPos <= OpVars.length; wkPos = wkPos + 1) {
wkIdx = wkPos - 1;
printf("Value = %d \n", *(cast(int*)(OpVars[wkIdx].Addr)));
}
}
However, the code below, changing the Type variable to char:
extern (C) void main() {
import core.stdc.stdio : printf;
size_t wkIdx;
size_t wkPos;
enum Count = 1;
struct OpVar {
void* Addr;
char Type;
}
OpVar[Count] OpVars;
int IntVar1 = 5;
OpVars[0].Addr = &IntVar1;
OpVars[0].Type = '1';
for (wkPos = 1; wkPos <= OpVars.length; wkPos = wkPos + 1) {
wkIdx = wkPos - 1;
printf("Value = %d \n", *(cast(int*)(OpVars[wkIdx].Addr)));
}
}
fails with:
addrtest.obj : error LNK2019: unresolved external symbol _memsetn referenced in function main
addrtest.exe : fatal error LNK1120: 1 unresolved externals
Error: linker exited with status 1120
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.41.34120\bin\HostX64\x64\link.exe /NOLOGO "addrtest.obj" /LIBPATH:"C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.41.34120\lib\x64" legacy_stdio_definitions.lib /LIBPATH:"C:\Program Files (x86)\Windows Kits\10\Lib\10.0.22000.0\ucrt\x64" /LIBPATH:"C:\Program Files (x86)\Windows Kits\10\lib\10.0.22000.0\um\x64"
Error: undefined reference to `_memsetn`
referenced from `main`
perhaps a library needs to be added with the `-L` flag or `pragma(lib, ...)`