RFR: JDK-8301481: Replace NULL with nullptr in os/windows

[Johan Sjölen]

On Tue, 31 Jan 2023 10:16:14 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

> Hi, this PR changes all occurrences of NULL to nullptr for the subdirectory os/windows. Unfortunately the script that does the change isn't perfect, and so we
> need to comb through these manually to make sure nothing has gone wrong. I also review these changes but things slip past my eyes sometimes.
> 
> Here are some typical things to look out for:
> 
> 1. No changes but copyright header changed (probably because I reverted some changes but forgot the copyright).
> 2. Macros having their NULL changed to nullptr, these are added to the script when I find them. They should be NULL.
> 3. nullptr in comments and logs. We try to use lower case "null" in these cases as it reads better. An exception is made when code expressions are in a comment.
> 
> An example of this:
> 
> ```c++
> // This function returns null
> void* ret_null();
> // This function returns true if *x == nullptr
> bool is_nullptr(void** x);
> 
> 
> Note how `nullptr` participates in a code expression here, we really are talking about the specific value `nullptr`.
> 
> Thanks!

Found some things that need fixing

src/hotspot/os/windows/gc/z/zMapper_windows.cpp line 69:

> 67:     MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, // AllocationType
> 68:     PAGE_NOACCESS,                         // PageProtection
> 69:     nullptr,                                  // ExtendedParameters

Align

src/hotspot/os/windows/gc/z/zMapper_windows.cpp line 104:

> 102:   HANDLE const res = ZSyscall::CreateFileMappingW(
> 103:     INVALID_HANDLE_VALUE,         // hFile
> 104:     NULL,                         // lpFileMappingAttribute

Align

src/hotspot/os/windows/gc/z/zMapper_windows.cpp line 136:

> 134:     file_handle,         // FileMapping
> 135:     GetCurrentProcess(), // ProcessHandle
> 136:     nullptr,                // BaseAddress

Align

src/hotspot/os/windows/gc/z/zMapper_windows.cpp line 141:

> 139:     0,                   // AllocationType
> 140:     PAGE_NOACCESS,       // PageProtection
> 141:     nullptr,                // ExtendedParameters

Align

src/hotspot/os/windows/gc/z/zMapper_windows.cpp line 168:

> 166:     MEM_COMMIT,          // AllocationType
> 167:     PAGE_NOACCESS,       // PageProtection
> 168:     nullptr,                // ExtendedParameters

Align

src/hotspot/os/windows/os_perf_windows.cpp line 674:

> 672: *
> 673: * @param pdh_artifact_idx   the counter index as specified in the registry
> 674: * @return                   localized pdh artifact string if successful, nullptr on failure.

null

src/hotspot/os/windows/os_perf_windows.cpp line 694:

> 692:  * Caller needs ResourceMark.
> 693:  *
> 694:  * @return the process image string description, nullptr if the call failed.

null

src/hotspot/os/windows/os_perf_windows.cpp line 787:

> 785:  * Caller needs ResourceMark;
> 786:  *
> 787:  * @return  buffer if successful, nullptr on failure.

null

src/hotspot/os/windows/os_perf_windows.cpp line 804:

> 802:                                                   nullptr, // instance buffer is null and
> 803:                                                   &i_size,  // pass 0 length in order to get the required size
> 804:                                                   PERF_DETAIL_WIZARD, // counter detail level

check align

src/hotspot/os/windows/os_perf_windows.cpp line 820:

> 818:                                        PERF_DETAIL_WIZARD, // counter detail level
> 819:                                        0);
> 820:   return PdhDll::PdhStatusFail(pdhStat) ? nullptr : instances;

align

src/hotspot/os/windows/windbghelp.cpp line 296:

> 294:     }
> 295: 
> 296:     FOR_ALL_FUNCTIONS(CHECK_AND_PRINT_IF_NULL)

fix

-------------

PR: https://git.openjdk.org/jdk/pull/12317