JDK-8301493: Replace NULL with nullptr in cpu/aarch64 #12321

jdksjolen · 2023-01-31T11:39:27Z

Hi, this PR changes all occurrences of NULL to nullptr for the subdirectory cpu/aarch64. 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:

No changes but copyright header changed (probably because I reverted some changes but forgot the copyright).
Macros having their NULL changed to nullptr, these are added to the script when I find them. They should be NULL.
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:

// 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!

Progress

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Change must not contain extraneous whitespace
Commit message must refer to an issue

Issue

JDK-8301493: Replace NULL with nullptr in cpu/aarch64

Reviewers

Thomas Schatzl (@tschatzl - Reviewer)
Gerard Ziemski (@gerard-ziemski - Committer) ⚠️ Review applies to 5cc7a5a7
David Holmes (@dholmes-ora - Reviewer) ⚠️ Review applies to 5cc7a5a7

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/12321/head:pull/12321
$ git checkout pull/12321

Update a local copy of the PR:
$ git checkout pull/12321
$ git pull https://git.openjdk.org/jdk.git pull/12321/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 12321

View PR using the GUI difftool:
$ git pr show -t 12321

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/12321.diff

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bridgekeeper · 2023-01-31T11:41:12Z

👋 Welcome back jsjolen! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2023-01-31T11:44:12Z

@jdksjolen The following labels will be automatically applied to this pull request:

hotspot
shenandoah

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

jdksjolen

Some simple fixes here

jdksjolen · 2023-01-31T15:24:21Z

src/hotspot/cpu/aarch64/frame_aarch64.inline.hpp

@@ -171,13 +171,13 @@ inline frame::frame(intptr_t* sp, intptr_t* fp) {
  // call a specilaized frame constructor instead of this one.
  // Then we could use the assert below. However this assert is of somewhat dubious
  // value.
-  // assert(_pc != NULL, "no pc?");
+  // assert(_pc != null, "no pc?");


jdksjolen · 2023-01-31T15:26:49Z

src/hotspot/cpu/aarch64/gc/g1/g1BarrierSetAssembler_aarch64.cpp

@@ -159,7 +159,7 @@ void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm,

  // Calling the runtime using the regular call_VM_leaf mechanism generates
  // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
-  // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
+  // that checks that the *(rfp+frame::interpreter_frame_last_sp) == null.


jdksjolen · 2023-01-31T15:27:24Z

src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp

@@ -157,7 +157,7 @@ void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,

  // Calling the runtime using the regular call_VM_leaf mechanism generates
  // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
-  // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
+  // that checks that the *(rfp+frame::interpreter_frame_last_sp) == null.


jdksjolen · 2023-01-31T15:27:39Z

src/hotspot/cpu/aarch64/icBuffer_aarch64.cpp

@@ -47,7 +47,7 @@ void InlineCacheBuffer::assemble_ic_buffer_code(address code_begin, void* cached
  // because
  // (1) the value is old (i.e., doesn't matter for scavenges)
  // (2) these ICStubs are removed *before* a GC happens, so the roots disappear
-  // assert(cached_value == NULL || cached_oop->is_perm(), "must be perm oop");
+  // assert(cached_value == null || cached_oop->is_perm(), "must be perm oop");


jdksjolen · 2023-01-31T15:27:52Z

src/hotspot/cpu/aarch64/interp_masm_aarch64.cpp

@@ -140,7 +140,7 @@ void InterpreterMacroAssembler::check_and_handle_earlyret(Register java_thread)
  if (JvmtiExport::can_force_early_return()) {
    Label L;
    ldr(rscratch1, Address(rthread, JavaThread::jvmti_thread_state_offset()));
-    cbz(rscratch1, L); // if (thread->jvmti_thread_state() == NULL) exit;
+    cbz(rscratch1, L); // if (thread->jvmti_thread_state() == null) exit;


jdksjolen · 2023-01-31T15:28:56Z

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -1155,7 +1155,7 @@ void MacroAssembler::lookup_interface_method(Register recv_klass,
      add(recv_klass, recv_klass, itentry_off);
  }

-  // for (scan = klass->itable(); scan->interface() != NULL; scan += scan_step) {
+  // for (scan = klass->itable(); scan->interface() != null; scan += scan_step) {


jdksjolen · 2023-01-31T15:29:41Z

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -4788,15 +4788,15 @@ address MacroAssembler::arrays_equals(Register a1, Register a2, Register tmp3,
  br(EQ, SAME);

  if (UseSimpleArrayEquals) {
-    Label NEXT_WORD, SHORT, TAIL03, TAIL01, A_MIGHT_BE_NULL, A_IS_NOT_NULL;
+    Label NEXT_WORD, SHORT, TAIL03, TAIL01, A_MIGHT_BE_nullptr, A_IS_NOT_NULL;


Fix this macro

jdksjolen · 2023-01-31T15:31:13Z

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp

-    //  if (src == NULL) return -1;
+    //  if (src == null) return -1;
    __ cbz(src, L_failed);

    //  if (src_pos < 0) return -1;
    __ tbnz(src_pos, 31, L_failed);  // i.e. sign bit set

-    //  if (dst == NULL) return -1;
+    //  if (dst == null) return -1;


jdksjolen · 2023-01-31T15:31:22Z

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp

-    //  assert(src->klass() != NULL);
+    //  assert(src->klass() != null);
    {


jdksjolen · 2023-01-31T15:32:33Z

src/hotspot/cpu/aarch64/templateTable_aarch64.cpp

@@ -3694,8 +3694,8 @@ void TemplateTable::instanceof() {
    __ bind(is_null);   // same as 'done'
  }
  __ bind(done);
-  // r0 = 0: obj == NULL or  obj is not an instanceof the specified klass
-  // r0 = 1: obj != NULL and obj is     an instanceof the specified klass


mlbridge · 2023-02-06T10:22:35Z

Webrevs

openjdk · 2023-02-17T18:57:57Z

@jdksjolen this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout JDK-8301493
git fetch https://git.openjdk.org/jdk master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

bridgekeeper · 2023-03-17T23:07:36Z

@jdksjolen This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

jdksjolen · 2023-03-21T09:54:30Z

Not yet.

stooart-mon · 2023-03-21T13:32:10Z

This looks OK so far.
However, is it your intention to also do aarch64.ad?
aarch64_ad.m4 and aarch64_vector(.ad|_ad.m4) files look clean.

stooart-mon · 2023-03-21T20:45:01Z

src/hotspot/cpu/aarch64/interpreterRT_aarch64.cpp

@@ -267,7 +267,7 @@ class SlowSignatureHandler

  virtual void pass_object() {
    intptr_t* addr = single_slot_addr();
-    intptr_t value = *addr == 0 ? NULL : (intptr_t)addr;
+    intptr_t value = *addr == 0 ? nullptr : (intptr_t)addr;


This doesn't compile - perhaps replace nullptr with zero? Unless casting it is more appropriate.

There's similar code in other patches, I did casting in those.

jdksjolen · 2023-04-11T13:17:01Z

This looks OK so far. However, is it your intention to also do aarch64.ad? aarch64_ad.m4 and aarch64_vector(.ad|_ad.m4) files look clean.

I'm only touching the .cpp/.hpp files in these PRs. The NULL count of all .ad files is only 339, so if I do those it'll all be in one commit (probably).

jdksjolen · 2023-05-02T13:06:11Z

Hi @stooart-mon , would you be interested in approving this :)? Thanks!

stooart-mon · 2023-05-02T15:55:28Z

As I'm only an author, I can't sponsor this patch, but it looks OK to me. It is consistent with the NULL->nullptr changes you have been doing elsewhere.

There might always be this problem, but there are some missing instances NULL that may have appeared since you started this - I've listed them below.

codeBuffer_aarch64.cpp:  if (cb->stubs()->maybe_expand_to_ensure_remaining(total_requested_size) && cb->blob() == NULL) {
gc/shared/barrierSetAssembler_aarch64.cpp:  __ cbz(obj, error);      // if klass is NULL it is broken
stubGenerator_aarch64.cpp:    if (bs_nm != NULL) {
vm_version_aarch64.cpp:    if (virt2 != NULL && strcasestr(line, virt2) != 0) {
vm_version_aarch64.cpp:  check_info_file(tname_file, "Xen", XenPVHVM, NULL, NoDetectedVirtualization);

tschatzl

Remaining NULL in

gc/shared/BarrierSetAssembler::check_oop()
codeBuffer_aarch64.cpp/emit_shared_trampolines()
stubGenerator_aarch64.cpp/generate_final_stubs()
vm_version_aarch64.cpp/check_info_file()

gerard-ziemski

I only looked at the changes that you did make, not what you could have done and it LGTM.

dholmes-ora

Looks good - thanks!

Three minor suggested changes and three opportunities to remove casts (that I spotted).

dholmes-ora · 2023-05-03T21:59:16Z

src/hotspot/cpu/aarch64/icache_aarch64.cpp

@@ -29,7 +29,7 @@
 void ICacheStubGenerator::generate_icache_flush(
                ICache::flush_icache_stub_t* flush_icache_stub) {
  // Give anyone who calls this a surprise
-  *flush_icache_stub = (ICache::flush_icache_stub_t)NULL;
+  *flush_icache_stub = (ICache::flush_icache_stub_t)nullptr;


Hopefully don't need the cast any more.

dholmes-ora · 2023-05-03T22:01:27Z

src/hotspot/cpu/aarch64/interpreterRT_aarch64.cpp

@@ -267,7 +267,7 @@ class SlowSignatureHandler

  virtual void pass_object() {
    intptr_t* addr = single_slot_addr();
-    intptr_t value = *addr == 0 ? NULL : (intptr_t)addr;
+    intptr_t value = *addr == 0 ? (intptr_t)nullptr : (intptr_t)addr;


This looks like it should be using 0 (zero) not NULL/nullptr?

dholmes-ora · 2023-05-03T22:02:22Z

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -968,7 +968,7 @@ void MacroAssembler::emit_static_call_stub() {
  // exact layout of this stub.

  isb();
-  mov_metadata(rmethod, (Metadata*)NULL);
+  mov_metadata(rmethod, (Metadata*)nullptr);


Shouldn't need cast any more.

dholmes-ora · 2023-05-03T22:03:06Z

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -1639,13 +1639,13 @@ void MacroAssembler::super_call_VM_leaf(address entry_point, Register arg_0, Reg

 void MacroAssembler::null_check(Register reg, int offset) {
  if (needs_explicit_null_check(offset)) {
-    // provoke OS NULL exception if reg = NULL by
+    // provoke OS null exception if reg = null by


Suggest reg is null

dholmes-ora · 2023-05-03T22:03:16Z

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

    // accessing M[reg] w/o changing any registers
    // NOTE: this is plenty to provoke a segv
    ldr(zr, Address(reg));
  } else {
    // nothing to do, (later) access of M[reg + offset]
-    // will provoke OS NULL exception if reg = NULL
+    // will provoke OS null exception if reg = null


Suggest reg is null

dholmes-ora · 2023-05-03T22:05:38Z

src/hotspot/cpu/aarch64/sharedRuntime_aarch64.cpp

@@ -1421,10 +1421,10 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
                                       stack_slots / VMRegImpl::slots_per_word,
                                       in_ByteSize(-1),
                                       in_ByteSize(-1),
-                                       (OopMapSet*)NULL);
+                                       (OopMapSet*)nullptr);


Shouldn't need cast any more

openjdk · 2023-05-04T12:08:59Z

@jdksjolen This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8301493: Replace NULL with nullptr in cpu/aarch64

Reviewed-by: tschatzl, gziemski, dholmes

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 341 new commits pushed to the master branch:

e19cf26: 8307196: Dangling pointer warning for MetadataAllocationRequest
1b143ba: 8307378: Allow collectors to provide specific values for GC notifications' actions
a44e890: 8307308: Add serviceability_ttf_virtual group to exclude jvmti tests developed for virtual threads
46df171: 8304948: [vectorapi] C2 crashes when expanding VectorBox
111858f: 8307489: ProblemList jdk/incubator/vector/LoadJsvmlTest.java on windows-x64
197d0cc: 8294983: SSLEngine throws ClassCastException during handshake
a87262e: 8307295: Add warning to not create new ACC flags
0c6529d: 8307156: native_thread not protected by TLH
5ca0b08: 8307133: Open source some JTable jtreg tests
2adb3b4: 8306943: Open source several dnd AWT tests
... and 331 more: https://git.openjdk.org/jdk/compare/cd7d53c88c27eedbe16020b88c2219708d170a1e...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

jdksjolen · 2023-05-04T20:09:03Z

Thanks @tschatzl, probably new code from when I merged that didn't get a conflict. I did a grep for NULL and checked that no more occurrences are in the code. Running tier1 testing.

tschatzl

Lgtm.

jdksjolen · 2023-05-05T08:52:44Z

Alright, tier1 looks good. Integrating. Thank you for the reviews, good people.

/integrate

openjdk · 2023-05-05T08:54:14Z

Going to push as commit 948f3b3.
Since your change was applied there have been 343 commits pushed to the master branch:

f94f957: 8307331: Correctly update line maps when class redefine rewrites bytecodes
302bc2f: 8307421: Fix comment in g1CollectionSetChooser.hpp after JDK-8306836
e19cf26: 8307196: Dangling pointer warning for MetadataAllocationRequest
1b143ba: 8307378: Allow collectors to provide specific values for GC notifications' actions
a44e890: 8307308: Add serviceability_ttf_virtual group to exclude jvmti tests developed for virtual threads
46df171: 8304948: [vectorapi] C2 crashes when expanding VectorBox
111858f: 8307489: ProblemList jdk/incubator/vector/LoadJsvmlTest.java on windows-x64
197d0cc: 8294983: SSLEngine throws ClassCastException during handshake
a87262e: 8307295: Add warning to not create new ACC flags
0c6529d: 8307156: native_thread not protected by TLH
... and 333 more: https://git.openjdk.org/jdk/compare/cd7d53c88c27eedbe16020b88c2219708d170a1e...master

Your commit was automatically rebased without conflicts.

openjdk · 2023-05-05T08:54:35Z

@jdksjolen Pushed as commit 948f3b3.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

Replace NULL with nullptr in cpu/aarch64

169ed13

openjdk bot added hotspot hotspot-dev@openjdk.org shenandoah shenandoah-dev@openjdk.org labels Jan 31, 2023

jdksjolen commented Jan 31, 2023

View reviewed changes

Fixes

86aa187

jdksjolen marked this pull request as ready for review February 6, 2023 10:17

openjdk bot added the rfr Pull request is ready for review label Feb 6, 2023

openjdk bot added the merge-conflict Pull request has merge conflict with target branch label Feb 17, 2023

stooart-mon reviewed Mar 21, 2023

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openjdk bot removed the rfr Pull request is ready for review label Apr 3, 2023

jdksjolen added 2 commits April 11, 2023 14:51

Explicitly cast

45ab2f0

Merge remote-tracking branch 'origin/master' into JDK-8301493

da8bba5

openjdk bot removed the merge-conflict Pull request has merge conflict with target branch label Apr 11, 2023

Fix style

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openjdk bot added the rfr Pull request is ready for review label Apr 11, 2023

tschatzl suggested changes May 3, 2023

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gerard-ziemski approved these changes May 3, 2023

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dholmes-ora approved these changes May 3, 2023

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dholmes' fixes

31b2ed1

openjdk bot added the ready Pull request is ready to be integrated label May 4, 2023

Missed these NULLs somehow

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tschatzl approved these changes May 5, 2023

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openjdk bot closed this May 5, 2023

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels May 5, 2023

JDK-8301493: Replace NULL with nullptr in cpu/aarch64 #12321

JDK-8301493: Replace NULL with nullptr in cpu/aarch64 #12321

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jdksjolen commented Jan 31, 2023 • edited by openjdk bot Loading

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