-
Notifications
You must be signed in to change notification settings - Fork 11.9k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
__noop
not marked as constexpr #102064
#105983
Conversation
Thank you for submitting a Pull Request (PR) to the LLVM Project! This PR will be automatically labeled and the relevant teams will be notified. If you wish to, you can add reviewers by using the "Reviewers" section on this page. If this is not working for you, it is probably because you do not have write permissions for the repository. In which case you can instead tag reviewers by name in a comment by using If you have received no comments on your PR for a week, you can request a review by "ping"ing the PR by adding a comment “Ping”. The common courtesy "ping" rate is once a week. Please remember that you are asking for valuable time from other developers. If you have further questions, they may be answered by the LLVM GitHub User Guide. You can also ask questions in a comment on this PR, on the LLVM Discord or on the forums. |
@llvm/pr-subscribers-clang Author: ofAlpaca (ofAlpaca) ChangesResolves #102064 llvm-project/clang/lib/Sema/SemaDecl.cpp Line 14402 in b6603e1
By adding a BI__noop case in bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp) should fix the problem.Correct me if there is anything I misunderstood. Full diff: https://github.com/llvm/llvm-project/pull/105983.diff 4 Files Affected:
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 971df672b6ca1e..e60407061ccd3b 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -861,6 +861,8 @@ Bug Fixes to Compiler Builtins
- Clang now allows pointee types of atomic builtin arguments to be complete template types
that was not instantiated elsewhere.
+- Fix ``__noop`` not marked as constexpr. (#GH102064)
+
Bug Fixes to Attribute Support
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Basic/Builtins.td b/clang/include/clang/Basic/Builtins.td
index f5b15cf90d1f83..b42f7ea1d9de68 100644
--- a/clang/include/clang/Basic/Builtins.td
+++ b/clang/include/clang/Basic/Builtins.td
@@ -2516,7 +2516,7 @@ def IsoVolatileStore : MSLangBuiltin, Int8_16_32_64Template {
def Noop : MSLangBuiltin {
let Spellings = ["__noop"];
- let Attributes = [NoThrow];
+ let Attributes = [NoThrow, Constexpr];
let Prototype = "int(...)";
}
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 5af712dd7257b1..d505346bccd9b3 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -12586,6 +12586,10 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
return false;
}
+ case Builtin::BI__noop:
+ // __noop always evaluates successfully
+ return true;
+
case Builtin::BI__builtin_is_constant_evaluated: {
const auto *Callee = Info.CurrentCall->getCallee();
if (Info.InConstantContext && !Info.CheckingPotentialConstantExpression &&
diff --git a/clang/test/SemaCXX/GH102064.cpp b/clang/test/SemaCXX/GH102064.cpp
new file mode 100644
index 00000000000000..0ed930439e3d75
--- /dev/null
+++ b/clang/test/SemaCXX/GH102064.cpp
@@ -0,0 +1,3 @@
+// RUN: %clang_cc1 -std=c++20 -fms-extensions %s
+// expected-no-diagnostics
+constexpr int x = []{ __noop; return 0; }();
|
@DanielJump
It looks like the problem is about Windows's backslash. |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Thank you! LGTM modulo tiny nits.
FWIW, the precommit CI failure looks unrelated to your changes, I wouldn't worry about it (the issue hopefully goes away if you rebase).
An off-topic concern: |
I am sorry, I couldn't make much headway in the last weeks because I was
still understanding the codebase. Please feel free to reassign. I will
attempt to take on issues in the future when I am much more prepared.
…On Tue, 27 Aug, 2024, 7:38 am Younan Zhang, ***@***.***> wrote:
An off-topic concern:
The issue was initially assigned to @AdiSin123
<https://github.com/AdiSin123> three weeks ago. Did you talk to @AdiSin123
<https://github.com/AdiSin123> to ensure that @AdiSin123
<https://github.com/AdiSin123> gives up the fix? It would be polite to
ask first in the issue before you start working on this.
—
Reply to this email directly, view it on GitHub
<#105983 (comment)>,
or unsubscribe
<https://github.com/notifications/unsubscribe-auth/AXOWFNB2G2TXNZCQ6QGUZQDZTPNQRAVCNFSM6AAAAABNCQBY4OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGMJRGQZTAMRWGY>
.
You are receiving this because you were mentioned.Message ID:
***@***.***>
|
@zyn0217 |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
LGTM, thanks
Will you need me to merge that for you?
@cor3ntin |
You have to resolve the conflict in |
@ofAlpaca Congratulations on having your first Pull Request (PR) merged into the LLVM Project! Your changes will be combined with recent changes from other authors, then tested by our build bots. If there is a problem with a build, you may receive a report in an email or a comment on this PR. Please check whether problems have been caused by your change specifically, as the builds can include changes from many authors. It is not uncommon for your change to be included in a build that fails due to someone else's changes, or infrastructure issues. How to do this, and the rest of the post-merge process, is covered in detail here. If your change does cause a problem, it may be reverted, or you can revert it yourself. This is a normal part of LLVM development. You can fix your changes and open a new PR to merge them again. If you don't get any reports, no action is required from you. Your changes are working as expected, well done! |
Resolves #102064
I think the problem is that the function
bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp)
return defaultfalse
directly when visiting expression of__noop
.Thus,
__noop
cannot be evaluated as constant initializer in here.llvm-project/clang/lib/Sema/SemaDecl.cpp
Line 14402 in b6603e1
By adding a
BI__noop
case inbool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E, unsigned BuiltinOp)
should fix the problem.Correct me if there is anything I misunderstood.