[clang] b88eb85 - [clang] use correct builtin type for defaulted comparison analyzer

[Matheus Izvekov via cfe-commits]

Author: Matheus Izvekov
Date: 2021-06-17T02:08:31+02:00
New Revision: b88eb855b53184161ad1ea0eea1962100941cf0b

URL: https://github.com/llvm/llvm-project/commit/b88eb855b53184161ad1ea0eea1962100941cf0b
DIFF: https://github.com/llvm/llvm-project/commit/b88eb855b53184161ad1ea0eea1962100941cf0b.diff

LOG: [clang] use correct builtin type for defaulted comparison analyzer

Fixes PR50591.

When analyzing classes with members which have user-defined conversion
operators to builtin types, the defaulted comparison analyzer was
picking the member type instead of the type for the builtin operator
which was selected as the best match.

This could either result in wrong comparison category being selected,
or a crash when runtime checks are enabled.

Signed-off-by: Matheus Izvekov <mizvekov at gmail.com>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D103760

Added: 
    

Modified: 
    clang/lib/Sema/SemaDeclCXX.cpp
    clang/test/CXX/class/class.compare/class.spaceship/p2.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index fd2d93e490c92..d39837d277045 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -7863,8 +7863,13 @@ class DefaultedComparisonAnalyzer
             return Result::deleted();
           }
         } else {
+          QualType T = Best->BuiltinParamTypes[0];
+          assert(T == Best->BuiltinParamTypes[1] &&
+                 "builtin comparison for 
diff erent types?");
+          assert(Best->BuiltinParamTypes[2].isNull() &&
+                 "invalid builtin comparison");
           Optional<ComparisonCategoryType> Cat =
-              getComparisonCategoryForBuiltinCmp(Args[0]->getType());
+              getComparisonCategoryForBuiltinCmp(T);
           assert(Cat && "no category for builtin comparison?");
           R.Category = *Cat;
         }

diff  --git a/clang/test/CXX/class/class.compare/class.spaceship/p2.cpp b/clang/test/CXX/class/class.compare/class.spaceship/p2.cpp
index 06126a48acf1a..47b14cb5f9616 100644
--- a/clang/test/CXX/class/class.compare/class.spaceship/p2.cpp
+++ b/clang/test/CXX/class/class.compare/class.spaceship/p2.cpp
@@ -172,3 +172,23 @@ namespace PR48856 {
     int C::*x;                                   // expected-note {{because there is no viable three-way comparison function for member 'x'}}
   };
 }
+
+namespace PR50591 {
+  struct a1 {
+    operator int() const;
+  };
+  struct b1 {
+    auto operator<=>(b1 const &) const = default;
+    a1 f;
+  };
+  std::strong_ordering cmp_b1 = b1() <=> b1();
+
+  struct a2 {
+    operator float() const;
+  };
+  struct b2 {
+    auto operator<=>(b2 const &) const = default;
+    a2 f;
+  };
+  std::partial_ordering cmp_b2 = b2() <=> b2();
+}