Bug 5305 – Cannot take pointer to intrinsic function

https://gist.github.com/724508 The code snippet compiles with -release, but not without. In -release mode, the maths intrinsics have the mangling for @safe removed ('Nf'), and so the linker chokes on the mangled signature (because libphobos2.a was compiled with -release.)

For convenience, here's the example: import std.math; T[] map(T, V)(T function(T) f, V[] list) { T[] result = new T[](list.length); foreach(k, v; list) { result[k] = f(v); } return result; } void main() { assert (map!(real, float) (&sqrt, [4.0f, 9.0f]) == [2.0f, 3.0f]); }

A reduced test case: import std.math; void map(real function(real) f) { } void main() { map(&sqrt); } What is happening here is that sqrt() is an intrinsic, it doesn't actually exist in the libphobos2.a. When compiled with -release, the assert() goes away, and sqrt is never referenced, hence no error. Without -release, the linker looks for std.math.sqrt, and can't find it because it's an intrinsic. The solution is one of: 1. have the compiler complain about attempts to take the address of an intrinsic 2. add a library version of the intrinsic

(In reply to comment #2) > The solution is one of: > > 1. have the compiler complain about attempts to take the address of an > intrinsic > > 2. add a library version of the intrinsic Is it possible for the D compiler to use the intrinsic in most cases when sqrt is used directly, and give the pointer to a library sqrt when the programmer uses a &sqrt?

Works with the current version of DMD. Adding a test case: https://github.com/dlang/dmd/pull/5845

As mentioned by #c2, the issue is taking a pointer to an intrinsic function. Closing as duplicate and renaming for clarity. *** This issue has been marked as a duplicate of issue 4541 ***

The test case I added is to verify that taking the address of sqrt from std.math works.

Commits pushed to master at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/fad9e24cff5aff88c5635b010076bf6d39e659e7 fix Issue 5305 - intrinsic functions have @safe stripped of them in release mode https://github.com/dlang/dmd/commit/5f8f6f569eb9d5076c8e2ad68237e18c86052eb0 Merge pull request #5845 from WalterBright/test5305 fix Issue 5305 - intrinsic functions have @safe stripped of them in r…

Commits pushed to stable at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/fad9e24cff5aff88c5635b010076bf6d39e659e7 fix Issue 5305 - intrinsic functions have @safe stripped of them in release mode https://github.com/dlang/dmd/commit/5f8f6f569eb9d5076c8e2ad68237e18c86052eb0 Merge pull request #5845 from WalterBright/test5305

dlang/dmd pull request #13016 "test: Remove test case for issue 5305" was merged into master: - 499d0aa53ac2b4d6a3c39dd7976432de4f926538 by Iain Buclaw: test: Remove test case for issue 5305 This test is already covered in Phobos std.math https://github.com/dlang/dmd/pull/13016

dlang/phobos pull request #8210 "std.math: Reference Issue 5305 in unittest taking pointer to function" was merged into master: - 5a39765c4c5e4c34cd5ee84bae0901af6869d66f by Iain Buclaw: std.math: Reference Issue 5305 in unittest taking pointer to function https://github.com/dlang/phobos/pull/8210