RFR: 8307160: [REDO] Enable the permissive- flag on the Microsoft Visual C compiler [v2]

[Julian Waters]

On Tue, 1 Aug 2023 08:10:10 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Julian Waters has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 22 additional commits since the last revision:
>> 
>>  - Mismatched declaration in D3DGlyphCache.cpp
>>  - Fields in awt_TextComponent.cpp
>>  - reinterpret_cast needed in AccessBridgeJavaEntryPoints.cpp
>>  - Qualifiers in awt_PrintDialog.h should be removed
>>  - Likewise for awt_DnDDT.cpp
>>  - awt_ole.h include order issue in awt_DnDDS.cpp
>>  - Revert awt_ole.h
>>  - Earlier fix in awt_ole.h was not complete
>>  - Merge branch 'openjdk:master' into patch-10
>>  - Likewise for awt_Frame.cpp
>>  - ... and 12 more: https://git.openjdk.org/jdk/compare/6432a4e7...51230f3d
>
> src/hotspot/os/windows/symbolengine.cpp line 114:
> 
>> 112:       _capacity = (int)(sizeof(_fallback_buffer) / sizeof(T));
>> 113:     }
>> 114:     _p[0] = (T) '\0';
> 
> I find this use of `'\0'` quite suspicious in itself, but it is consistent with the use of `'X'` in `imprint_sentinel()`. I'm unclear what types are possible for `T` in this code.

There are currently only 2 possible types of HMODULE and char/uint8_t for T at the moment. Weirdly enough only line 126 errors out without the cast while line 114, despite having the same problem, doesn't, but I added the cast to both lines for consistency. If someone else knows why I could probably deal with this code in a better way besides just casting it to T (which I also am reluctant to do)

> src/hotspot/share/memory/allocation.cpp line 114:
> 
>> 112: //
>> 113: 
>> 114: void* AnyObj::operator new(size_t size, Arena *arena) {
> 
> Please remind us what the issue is with `throw()` as this is a change to shared code and it looks very inconsistent to remove it only for this one definition of `operator new`.

Hi David, this throw was removed for this method's declaration in the corresponding hpp file in an earlier commit [8305590: Remove nothrow exception specifications from operator new](https://github.com/openjdk/jdk/commit/0f51e6326373ff7d4a4d9a0e3a2788401f73405d), but the Author forgot to remove the throw() from the definition as well (the error can be viewed in the GHA for the earlier versions of this PR). I believe gcc only errors on this in C++17 mode (for some weird reason) and not our current C++14 mode, which is why it gets a pass on other platforms

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PR Review Comment: https://git.openjdk.org/jdk/pull/15096#discussion_r1280269818
PR Review Comment: https://git.openjdk.org/jdk/pull/15096#discussion_r1280267058