#pragma init_seg(section-specifier, func-name) not supported

[AdamGlass]

This MSVC pragma is only partially implemented. As detailed here, there is functionality to specify a function to call in place of atexit.

https://learn.microsoft.com/en-us/cpp/preprocessor/init-seg?view=msvc-170

"func-name
Specifies a function to be called in place of atexit when the program exits. This helper function also calls atexit with a pointer to the destructor for the global object. If you specify a function identifier in the pragma of the form,

C++

Copy
int __cdecl myexit (void (__cdecl *pf)(void))
then your function will be called instead of the C run-time library's atexit. It allows you to build a list of the destructors to call when you're ready to destroy the objects."

Relevant code in ParsePragma.cpp:Parser::HandlePragmaMSInitSeg:
// FIXME: Add support for the '[, func-name]' part of the pragma.

Maybe a good early OSS contribution given the limited use and lack of potential for regression

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Adam Glass (AdamGlass)

This MSVC pragma is only partially implemented. As detailed here, there is functionality to specify a function to call in place of atexit.

https://learn.microsoft.com/en-us/cpp/preprocessor/init-seg?view=msvc-170

"func-name
Specifies a function to be called in place of atexit when the program exits. This helper function also calls atexit with a pointer to the destructor for the global object. If you specify a function identifier in the pragma of the form,

C++

Copy
int __cdecl myexit (void (__cdecl *pf)(void))
then your function will be called instead of the C run-time library's atexit. It allows you to build a list of the destructors to call when you're ready to destroy the objects."

Relevant code in ParsePragma.cpp:Parser::HandlePragmaMSInitSeg:
// FIXME: Add support for the '[, func-name]' part of the pragma.

Maybe a good early OSS contribution given the limited use and lack of potential for regression

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor is working on this issue. If someone is assigned to the issue or claimed to be working on it, ping the person. After one week without a response, the assignee may be changed.
2. Leave a comment indicating that you are working on the issue, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
6. Run git clang-format HEAD~1 to format your changes.
7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: Adam Glass (AdamGlass)

This MSVC pragma is only partially implemented. As detailed here, there is functionality to specify a function to call in place of atexit.

https://learn.microsoft.com/en-us/cpp/preprocessor/init-seg?view=msvc-170

"func-name
Specifies a function to be called in place of atexit when the program exits. This helper function also calls atexit with a pointer to the destructor for the global object. If you specify a function identifier in the pragma of the form,

C++

Copy
int __cdecl myexit (void (__cdecl *pf)(void))
then your function will be called instead of the C run-time library's atexit. It allows you to build a list of the destructors to call when you're ready to destroy the objects."

Relevant code in ParsePragma.cpp:Parser::HandlePragmaMSInitSeg:
// FIXME: Add support for the '[, func-name]' part of the pragma.

Maybe a good early OSS contribution given the limited use and lack of potential for regression

[rhyadav]

Hi,
I would like to contribute to this thanks @AdamGlass