clang-cl ignores -Wpadded

[cairnc]

On Windows this compiles with clang -Wpadded -Werror

typedef struct
{
    int x;
    char y;
} Foo;

int main()
{
    Foo foo;
}

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: None (cairnc)

On Windows this compiles with `clang -Wpadded -Werror`

typedef struct
{
    int x;
    char y;
} Foo;

int main()
{
    Foo foo;
}

[AaronBallman]

The issue is that we only implemented that diagnostic for Itanium record layouts and not Microsoft ones.

llvm-project/clang/lib/AST/RecordLayoutBuilder.cpp

Line 2188 in b51fc2a

Diag(RD->getLocation(), diag::warn_padded_struct_size)

llvm-project/clang/lib/AST/RecordLayoutBuilder.cpp

Line 3201 in b51fc2a

void MicrosoftRecordLayoutBuilder::finalizeLayout(const RecordDecl *RD) {

[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 has already been assigned to this issue. If you believe that no one is actually working on it despite an assignment, ping the person. After one week without a response, the assignee may be changed.
2. In the comments of this issue, request for it to be assigned to you, 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: None (cairnc)

On Windows this compiles with `clang -Wpadded -Werror`

typedef struct
{
    int x;
    char y;
} Foo;

int main()
{
    Foo foo;
}

[theomagellan]

Hi @AaronBallman! I would like to get assigned to this issue. This would be my first contribution and since it is marked as 'good first issue' I would love to take a crack at it!