Merge branch 'master' into devel/sphinx

4 files changed, 35 insertions, 1 deletions

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index bb85e78..ee7b511 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,8 @@
+2022-10-26  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/106393
+	* c.opt (Wdangling-reference): New.
+
 2022-10-19  Joseph Myers  <joseph@codesourcery.com>
 
 	* c-format.h (enum format_lengths): Add FMT_LEN_w8, FMT_LEN_w16,
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 62ab4ba..f9d0d29 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1004,6 +1004,30 @@ extern void c_parse_final_cleanups (void);
 /* True iff TYPE is cv decltype(nullptr).  */
 #define NULLPTR_TYPE_P(TYPE) (TREE_CODE (TYPE) == NULLPTR_TYPE)
 
+/* Returns the underlying type of the given enumeration type. The
+   underlying type is determined in different ways, depending on the
+   properties of the enum:
+
+     - In C++0x or C2x, the underlying type can be explicitly specified, e.g.,
+
+         enum E1 : char { ... } // underlying type is char
+
+     - In a C++0x scoped enumeration, the underlying type is int
+       unless otherwises specified:
+
+         enum class E2 { ... } // underlying type is int
+
+     - Otherwise, the underlying type is determined based on the
+       values of the enumerators. In this case, the
+       ENUM_UNDERLYING_TYPE will not be set until after the definition
+       of the enumeration is completed by finish_enum.  */
+#define ENUM_UNDERLYING_TYPE(TYPE) \
+  TREE_TYPE (ENUMERAL_TYPE_CHECK (TYPE))
+
+/* Determines whether an ENUMERAL_TYPE has an explicit
+   underlying type.  */
+#define ENUM_FIXED_UNDERLYING_TYPE_P(NODE) (TYPE_LANG_FLAG_5 (NODE))
+
 extern tree do_case (location_t, tree, tree, tree);
 extern tree build_stmt (location_t, enum tree_code, ...);
 extern tree build_real_imag_expr (location_t, enum tree_code, tree);
diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc
index 6742f44..cd59c3c 100644
--- a/gcc/c-family/c-warn.cc
+++ b/gcc/c-family/c-warn.cc
@@ -1415,7 +1415,8 @@ warnings_for_convert_and_check (location_t loc, tree type, tree expr,
 
   if (TREE_CODE (expr) == INTEGER_CST
       && (TREE_CODE (type) == INTEGER_TYPE
-	  || TREE_CODE (type) == ENUMERAL_TYPE)
+	  || (TREE_CODE (type) == ENUMERAL_TYPE
+	      && TREE_CODE (ENUM_UNDERLYING_TYPE (type)) != BOOLEAN_TYPE))
       && !int_fits_type_p (expr, type))
     {
       /* Do not diagnose overflow in a constant expression merely
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 01d4807..070f85c 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -555,6 +555,10 @@ Wdangling-pointer=
 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_dangling_pointer) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 2, 0) IntegerRange(0, 2)
 Warn for uses of pointers to auto variables whose lifetime has ended.
 
+Wdangling-reference
+C++ ObjC++ Var(warn_dangling_reference) Warning LangEnabledBy(C++ ObjC++, Wall)
+Warn when a reference is bound to a temporary whose lifetime has ended.
+
 Wdate-time
 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.