[clang] [Clang] fix range calculation for conditionals with throw expressions (PR #112081)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Oleksandr T. (a-tarasyuk)

<details>
<summary>Changes</summary>

Fixes #<!-- -->111854

---
Full diff: https://github.com/llvm/llvm-project/pull/112081.diff


3 Files Affected:

- (modified) clang/docs/ReleaseNotes.rst (+1) 
- (modified) clang/lib/Sema/SemaChecking.cpp (+3) 
- (modified) clang/test/SemaCXX/conditional-expr.cpp (+7) 


``````````diff
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 337e3fc10bf49d..2ab13640bfa53c 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -512,6 +512,7 @@ Bug Fixes to C++ Support
   and undeclared templates. (#GH107047, #GH49093)
 - Clang no longer crashes when a lambda contains an invalid block declaration that contains an unexpanded
   parameter pack. (#GH109148)
+- Fixed assertion failure in range calculations for conditional throw expressions (#GH111854)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 2bcb930acdcb57..b3d88f053872c1 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -9827,6 +9827,9 @@ static IntRange GetExprRange(ASTContext &C, const Expr *E, unsigned MaxWidth,
     return IntRange(BitField->getBitWidthValue(C),
                     BitField->getType()->isUnsignedIntegerOrEnumerationType());
 
+  if (GetExprType(E)->isVoidType())
+    return IntRange{0, true};
+
   return IntRange::forValueOfType(C, GetExprType(E));
 }
 
diff --git a/clang/test/SemaCXX/conditional-expr.cpp b/clang/test/SemaCXX/conditional-expr.cpp
index 01effaa189322b..8f17555fd806ff 100644
--- a/clang/test/SemaCXX/conditional-expr.cpp
+++ b/clang/test/SemaCXX/conditional-expr.cpp
@@ -429,3 +429,10 @@ void g() {
   long e = a = b ? throw 0 : throw 1;
 }
 } // namespace PR46484
+
+namespace GH111854 {
+void f() {
+  (true ? throw 0 : 0) <= 0;  // expected-warning {{relational comparison result unused}}
+  (false ? 0 : throw 0) <= 0; // expected-warning {{relational comparison result unused}}
+}
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/112081