2 files changed, 115 insertions, 0 deletions

diff --git a/meta/recipes-devtools/gcc/gcc-14.2.inc b/meta/recipes-devtools/gcc/gcc-14.2.inc
index e90b5b4c2a..932a27995b 100644
--- a/meta/recipes-devtools/gcc/gcc-14.2.inc
+++ b/meta/recipes-devtools/gcc/gcc-14.2.inc
@@ -68,6 +68,7 @@ SRC_URI = "${BASEURI} \
            file://0023-Fix-install-path-of-linux64.h.patch \
            file://0024-Avoid-hardcoded-build-paths-into-ppc-libgcc.patch \
            file://0025-gcc-testsuite-tweaks-for-mips-OE.patch \
+           file://0026-gcc-Fix-c-tweak-for-Wrange-loop-construct.patch \
            file://gcc.git-ab884fffe3fc82a710bea66ad651720d71c938b8.patch \
 "
 
diff --git a/meta/recipes-devtools/gcc/gcc/0026-gcc-Fix-c-tweak-for-Wrange-loop-construct.patch b/meta/recipes-devtools/gcc/gcc/0026-gcc-Fix-c-tweak-for-Wrange-loop-construct.patch
new file mode 100644
index 0000000000..c9bc863eea
--- /dev/null
+++ b/meta/recipes-devtools/gcc/gcc/0026-gcc-Fix-c-tweak-for-Wrange-loop-construct.patch
@@ -0,0 +1,114 @@
+From 05106fea707f010779369c5d6e89787953d2976f Mon Sep 17 00:00:00 2001
+From: Sunil Dora <sunilkumar.dora@windriver.com>
+Date: Wed, 11 Dec 2024 10:04:56 -0800
+Subject: [PATCH] gcc: Fix c++: tweak for Wrange-loop-construct
+
+This commit updates the warning to use a check for "trivially constructible" instead of
+"trivially copyable." The original check was incorrect, as "trivially copyable" only applies
+to types that can be copied trivially, whereas "trivially constructible" is the correct check
+for types that can be trivially default-constructed.
+
+This change ensures the warning is more accurate and aligns with the proper type traits.
+
+LLVM accepted a similar fix:
+https://github.com/llvm/llvm-project/issues/47355
+
+PR c++/116731 [https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116731]
+
+Upstream-Status: Backport [https://gcc.gnu.org/g:6ac4e2f4b2ca9980670e7d3815a9140730df1005]
+
+Signed-off-by: Marek Polacek <polacek@redhat.com>
+Signed-off-by: Sunil Dora <sunilkumar.dora@windriver.com>
+---
+ gcc/cp/parser.cc                              |  8 ++-
+ .../g++.dg/warn/Wrange-loop-construct3.C      | 57 +++++++++++++++++++
+ 2 files changed, 62 insertions(+), 3 deletions(-)
+ create mode 100644 gcc/testsuite/g++.dg/warn/Wrange-loop-construct3.C
+
+diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
+index 7e81c1010..8206489a2 100644
+--- a/gcc/cp/parser.cc
++++ b/gcc/cp/parser.cc
+@@ -14301,11 +14301,13 @@ warn_for_range_copy (tree decl, tree expr)
+   else if (!CP_TYPE_CONST_P (type))
+     return;
+ 
+-  /* Since small trivially copyable types are cheap to copy, we suppress the
+-     warning for them.  64B is a common size of a cache line.  */
++  /* Since small trivially constructible types are cheap to construct, we 
++     suppress the warning for them.  64B is a common size of a cache line.  */
++  tree vec = make_tree_vec (1);
++  TREE_VEC_ELT (vec, 0) = TREE_TYPE (expr);
+   if (TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
+       || (tree_to_uhwi (TYPE_SIZE_UNIT (type)) <= 64
+-         && trivially_copyable_p (type)))
++         && is_trivially_xible (INIT_EXPR, type, vec)))
+     return;
+ 
+   /* If we can initialize a reference directly, suggest that to avoid the
+diff --git a/gcc/testsuite/g++.dg/warn/Wrange-loop-construct3.C b/gcc/testsuite/g++.dg/warn/Wrange-loop-construct3.C
+new file mode 100644
+index 000000000..3d9d0c908
+--- /dev/null
++++ b/gcc/testsuite/g++.dg/warn/Wrange-loop-construct3.C
+@@ -0,0 +1,57 @@
++// PR c++/116731
++// { dg-do compile { target c++11 } }
++// { dg-options "-Wrange-loop-construct" }
++
++void
++f0 ()
++{
++  struct S {
++    char a[64];
++    S& operator=(const S&) { return *this; };
++  };
++
++  S arr[8];
++  for (const auto r : arr)
++    (void) r;
++}
++
++void
++f1 ()
++{
++  struct S {
++    char a[65];
++    S& operator=(const S&) { return *this; };
++  };
++
++  S arr[8];
++  for (const auto r : arr) // { dg-warning "creates a copy" }
++    (void) r;
++}
++
++void
++f2 ()
++{
++  struct S {
++    char a[64];
++    S& operator=(const S&) { return *this; };
++    ~S() { }
++  };
++
++  S arr[8];
++  for (const auto r : arr) // { dg-warning "creates a copy" }
++    (void) r;
++}
++
++void
++f3 ()
++{
++  struct S {
++    char a[65];
++    S& operator=(const S&) { return *this; };
++    ~S() { }
++  };
++
++  S arr[8];
++  for (const auto r : arr) // { dg-warning "creates a copy" }
++    (void) r;
++}
+-- 
+2.43.0
+