[clang] Improve diagnostics for vector builtins (#125673)

This commit improves the diagnostics for vector (elementwise) builtins
in a couple of ways.

It primarily provides more precise type-checking diagnostics for
builtins with specific type requirements. Previously many builtins were
receiving a catch-all diagnostic suggesting types which aren't valid.

It also makes consistent the type-checking behaviour between various
binary and ternary builtins. The binary builtins would check for
mismatched argument types before specific type requirements, whereas
ternary builtins would perform the checks in the reverse order. The
binary builtins now behave as the ternary ones do.

Author: frasercrmck

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -12523,16 +12523,31 @@ def err_builtin_is_within_lifetime_invalid_arg : Error<
   "%select{non-|function }0pointer argument to '__builtin_is_within_lifetime' "
   "is not allowed">;
 
-def err_builtin_invalid_arg_type: Error <
-  "%ordinal0 argument must be "
-  "%select{a vector, integer or floating point type|a matrix|"
-  "a pointer to a valid matrix element type|"
-  "a signed integer or floating point type|a vector type|"
-  "a floating point type|"
-  "a vector of integers|"
-  "an unsigned integer|"
-  "an 'int'|"
-  "a vector of floating points}1 (was %2)">;
+// A multi-component builtin type diagnostic. The first component broadly
+// selects a scalar or container type (scalar, vector or matrix). The second
+// component selects integer types and the third component selects
+// floating-point types. Any component can be left empty.
+def err_builtin_invalid_arg_type: Error<
+  "%ordinal0 argument must be a "
+  // First component: scalar or container types
+  "%select{|scalar|vector|matrix|vector of|scalar or vector of}1"
+  // A comma after generic vector/matrix types if there are non-empty second
+  // and third components, to initiate a list.
+  "%plural{[2,3]:%plural{0:|:%plural{0:|:,}2}3|:}1"
+  // A space after a non-empty first component
+  "%plural{0:|: }1"
+  // Second component: integer-like types
+  "%select{|integer|signed integer|unsigned integer|'int'|"
+  "pointer to a valid matrix element}2"
+  // A space after a non-empty second component
+  "%plural{0:|: }2"
+  // An 'or' if non-empty second and third components are combined
+  "%plural{0:|:%plural{0:|:or }2}3"
+  // Third component: floating-point types
+  "%select{|floating-point}3"
+  // A space after a non-empty third component
+  "%plural{0:|: }3"
+  "%plural{[0,3]:type|:types}1 (was %4)">;
 
 def err_builtin_matrix_disabled: Error<
   "matrix types extension is disabled. Pass -fenable-matrix to enable it">;

clang/include/clang/Sema/Sema.h

@@ -2353,9 +2353,18 @@ class Sema final : public SemaBase {
   bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
                          const FunctionProtoType *Proto);
 
+  enum class EltwiseBuiltinArgTyRestriction {
+    None,
+    FloatTy,
+    IntegerTy,
+    SignedIntOrFloatTy,
+  };
+
   /// \param FPOnly restricts the arguments to floating-point types.
-  std::optional<QualType> BuiltinVectorMath(CallExpr *TheCall,
-                                            bool FPOnly = false);
+  std::optional<QualType>
+  BuiltinVectorMath(CallExpr *TheCall,
+                    EltwiseBuiltinArgTyRestriction ArgTyRestr =
+                        EltwiseBuiltinArgTyRestriction::None);
   bool BuiltinVectorToScalarMath(CallExpr *TheCall);
 
   void checkLifetimeCaptureBy(FunctionDecl *FDecl, bool IsMemberFunction,
@@ -2459,9 +2468,13 @@ class Sema final : public SemaBase {
                                bool *ICContext = nullptr,
                                bool IsListInit = false);
 
-  bool BuiltinElementwiseTernaryMath(CallExpr *TheCall,
-                                     bool CheckForFloatArgs = true);
-  bool PrepareBuiltinElementwiseMathOneArgCall(CallExpr *TheCall);
+  bool
+  BuiltinElementwiseTernaryMath(CallExpr *TheCall,
+                                EltwiseBuiltinArgTyRestriction ArgTyRestr =
+                                    EltwiseBuiltinArgTyRestriction::FloatTy);
+  bool PrepareBuiltinElementwiseMathOneArgCall(
+      CallExpr *TheCall, EltwiseBuiltinArgTyRestriction ArgTyRestr =
+                             EltwiseBuiltinArgTyRestriction::None);
 
 private:
   void CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
@@ -2570,7 +2583,9 @@ class Sema final : public SemaBase {
                                  AtomicExpr::AtomicOp Op);
 
   /// \param FPOnly restricts the arguments to floating-point types.
-  bool BuiltinElementwiseMath(CallExpr *TheCall, bool FPOnly = false);
+  bool BuiltinElementwiseMath(CallExpr *TheCall,
+                              EltwiseBuiltinArgTyRestriction ArgTyRestr =
+                                  EltwiseBuiltinArgTyRestriction::None);
   bool PrepareBuiltinReduceMathOneArgCall(CallExpr *TheCall);
 
   bool BuiltinNonDeterministicValue(CallExpr *TheCall);