Re: Making a D library for a C executable
On Thursday, 27 April 2023 at 21:34:17 UTC, Steven Schveighoffer
wrote:
Also, please include your commands for building the D library
so reproduction is possible.
-Steve
I used to `dub run` to solve the problem, nothing special. My
`dub.json` isn't that interesting either, but I'll show it anyway
for the sake of reproduction purposes:
```json
{
"authors": [
"Jan Allersma"
],
"copyright": "Copyright © 2023, Jan Allersma",
"dependencies": {
"d2sqlite3": "~>1.0.0",
"secured": "~>2.0.2"
},
"description": "A minimal D application.",
"license": "proprietary",
"name": "shared-api",
"targetType": "dynamicLibrary",
"targetPath": "../build"
}
```
For people that use a Linux machine and don't have experience
with using shared libraries just like me: Don't forget to add
your shared library to a library path (e.g. `/usr/local/lib`).
And just to be sure, I also executed `ldconfig` in Bash.
Re: Making a D library for a C executable
On Thursday, 27 April 2023 at 21:34:17 UTC, Steven Schveighoffer wrote: You may have to link the library second. Sometimes linkers are particular about object order. Hi Steve, Your suggestion worked! Reversing the order solved the problem. I have another problem that I'm facing, but that is something hardly related to this so I'll open a new thread. Thanks :)
Re: Making a D library for a C executable
On 4/27/23 5:29 PM, Jan Allersma wrote: On Thursday, 27 April 2023 at 21:05:00 UTC, Mike Parker wrote: That's a compilation error, not a linker problem. You need to tell the compiler about the function with a prototype: Declaring the function does fix the compiler problem. However, I do get a linker error once I compile that: ```bash $ g++ ../build/libshared-api.so main.cpp /usr/bin/ld: /tmp/ccNMKxEE.o: in function `main': main.cpp:(.text+0x2a): undefined reference to `foo()' collect2: error: ld returned 1 exit status ``` You may have to link the library second. Sometimes linkers are particular about object order. Also, please include your commands for building the D library so reproduction is possible. -Steve
Re: Making a D library for a C executable
On Thursday, 27 April 2023 at 21:05:00 UTC, Mike Parker wrote: That's a compilation error, not a linker problem. You need to tell the compiler about the function with a prototype: Declaring the function does fix the compiler problem. However, I do get a linker error once I compile that: ```bash $ g++ ../build/libshared-api.so main.cpp /usr/bin/ld: /tmp/ccNMKxEE.o: in function `main': main.cpp:(.text+0x2a): undefined reference to `foo()' collect2: error: ld returned 1 exit status ```
Re: Making a D library for a C executable
On Thursday, 27 April 2023 at 20:32:24 UTC, Jan Allersma wrote:
```
Apparently foo isn't found from the CPP source file. Anyone
some ideas on how to solve this? :)
That's a compilation error, not a linker problem. You need to
tell the compiler about the function with a prototype:
```C++
#include
int foo();
int main() {
std::cout << "deede" << foo() << std::endl;
}
```
Making a D library for a C executable
Hello,
I see some examples on the internet on how to call C(++) in D.
But I want to do it the other way around. Because of (probably)
linkage issues, this way seems easier. I have this D code:
```
import std.stdio;
int maint() {
writeln("Returning some random stuff...");
return 10;
}
extern (C++) int foo() {
return maint();
}
```
And this CPP source file:
```
#include
int main() {
std::cout << "deede" << foo() << std::endl;
}
```
This is some gibberish, but the point is that foo needs to be
called from the D source file.
In Bash I compile it and get a response:
```
$ g++ ../build/libshared-api.so main.cpp
main.cpp: In function ‘int main()’:
main.cpp:4:27: error: ‘foo’ was not declared in this scope
4 | std::cout << "deede" << foo() << std::endl;
|
```
Apparently foo isn't found from the CPP source file. Anyone some
ideas on how to solve this? :)
