[clang-tidy] Ignore if consteval in else-after-return

[JoverZhang]

Fixes #91561.

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[cjdb]

Thanks for your patch! Would you be able to add a test case for this please?

[JoverZhang]

Thanks for your patch! Would you be able to add a test case for this please?

Yes, thanks. I added a test case.

[llvmbot]

@llvm/pr-subscribers-clang-tools-extra

@llvm/pr-subscribers-clang-tidy

Author: Jover (JoverZhang)

Changes

Fixes #91561.

---

Full diff: https://github.com/llvm/llvm-project/pull/91588.diff

2 Files Affected:

• (modified) clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp (+2-2)
• (added) clang-tools-extra/test/clang-tidy/checkers/readability/else-after-return-if-consteval.cpp (+17)

diff --git a/clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp b/clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp
index 1e85caf688355..2b185e7594add 100644
--- a/clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp
@@ -113,7 +113,7 @@ static bool containsDeclInScope(const Stmt *Node) {
 }
 
 static void removeElseAndBrackets(DiagnosticBuilder &Diag, ASTContext &Context,
-                           const Stmt *Else, SourceLocation ElseLoc) {
+                                  const Stmt *Else, SourceLocation ElseLoc) {
   auto Remap = [&](SourceLocation Loc) {
     return Context.getSourceManager().getExpansionLoc(Loc);
   };
@@ -172,7 +172,7 @@ void ElseAfterReturnCheck::registerMatchers(MatchFinder *Finder) {
       breakStmt().bind(InterruptingStr), cxxThrowExpr().bind(InterruptingStr)));
   Finder->addMatcher(
       compoundStmt(
-          forEach(ifStmt(unless(isConstexpr()),
+          forEach(ifStmt(unless(isConstexpr()), unless(isConsteval()),
                          hasThen(stmt(
                              anyOf(InterruptsControlFlow,
                                    compoundStmt(has(InterruptsControlFlow))))),
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/else-after-return-if-consteval.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/else-after-return-if-consteval.cpp
new file mode 100644
index 0000000000000..6235d8623ca7b
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/else-after-return-if-consteval.cpp
@@ -0,0 +1,17 @@
+// RUN: %check_clang_tidy -std=c++20 %s readability-else-after-return %t 
+
+// Consteval if is an exception to the rule, we cannot remove the else.
+void f() {
+  if (sizeof(int) > 4) {
+    return;
+  } else {
+    return;
+  }
+  // CHECK-MESSAGES: [[@LINE-3]]:5: warning: do not use 'else' after 'return'
+
+  if consteval {
+    return;
+  } else {
+    return;
+  }
+}

[5chmidti]

Please add an entry to the release notes here:

llvm-project/clang-tools-extra/docs/ReleaseNotes.rst

Line 176 in 502e77d

Changes in existing checks

do note that the entries are sorted by their check names.

Otherwise looks good.

[5chmidti]

While consteval was added in C++20, if consteval is a C++23 feature. Please use -std=c++23
https://en.cppreference.com/w/cpp/language/if#Consteval_if

[JoverZhang]

Please add an entry to the release notes here:

llvm-project/clang-tools-extra/docs/ReleaseNotes.rst

Line 176 in 502e77d

Changes in existing checks

do note that the entries are sorted by their check names.
Otherwise looks good.

Okay, I added.

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[SimplyDanny]

Thank you, @JoverZhang!