[Clang] avoid adding consteval condition as the last statement to preserve valid CFG #116513
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
llvmbot
added
clang
|
@llvm/pr-subscribers-clang-analysis @llvm/pr-subscribers-clang Author: Oleksandr T. (a-tarasyuk) ChangesFixes #116485 Full diff: https://github.com/llvm/llvm-project/pull/116513.diff 3 Files Affected:
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index a8830a5658c7da..d81085d011b866 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -535,6 +535,8 @@ Improvements to Clang's diagnostics
- Improved diagnostic message for ``__builtin_bit_cast`` size mismatch (#GH115870).
+- Clang now diagnoses missing return value in functions containing ``if consteval`` (#GH116485).
+
Improvements to Clang's time-trace
----------------------------------
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index f678ac6f2ff36a..7a6bd8b6f8d070 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -3177,11 +3177,14 @@ CFGBlock *CFGBuilder::VisitIfStmt(IfStmt *I) {
if (!I->isConsteval())
KnownVal = tryEvaluateBool(I->getCond());
- // Add the successors. If we know that specific branches are
+ // Add the successors. If we know that specific branches are
// unreachable, inform addSuccessor() of that knowledge.
addSuccessor(Block, ThenBlock, /* IsReachable = */ !KnownVal.isFalse());
addSuccessor(Block, ElseBlock, /* IsReachable = */ !KnownVal.isTrue());
+ if (I->isConsteval())
+ return Block;
+
// Add the condition as the last statement in the new block. This may
// create new blocks as the condition may contain control-flow. Any newly
// created blocks will be pointed to be "Block".
diff --git a/clang/test/SemaCXX/constexpr-return-non-void-cxx2b.cpp b/clang/test/SemaCXX/constexpr-return-non-void-cxx2b.cpp
index 25d1f8df7f7166..3d993f000e8dda 100644
--- a/clang/test/SemaCXX/constexpr-return-non-void-cxx2b.cpp
+++ b/clang/test/SemaCXX/constexpr-return-non-void-cxx2b.cpp
@@ -5,3 +5,9 @@ static_assert(__is_same(decltype([] constexpr -> int { }( )), int)); // expected
consteval int g() { } // expected-warning {{non-void function does not return a value}}
static_assert(__is_same(decltype([] consteval -> int { }( )), int)); // expected-warning {{non-void lambda does not return a value}}
+
+namespace GH116485 {
+int h() {
+ if consteval { }
+} // expected-warning {{non-void function does not return a value}}
+}
|
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/65/builds/8073 Here is the relevant piece of the build log for the reference |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/154/builds/7766 Here is the relevant piece of the build log for the reference |
a-tarasyuk
added a commit
that referenced
this pull request
Nov 27, 2024
…ow terminators (#117403) Fixes #117385 --- These changes extend the work done in #116513. The changes add additional handling to ensure correct behavior by skipping further checks when a **CFG** contains a `consteval` condition, where no _explicit expression_ is present, which is required to proceed with consumed analyses.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fixes #116485