protobuf: Fix static init fiasco on 3.15.2

The protobuf 3.15.2 suffers from the C++ "Static Initialization Fiasco"
issue. This patches makes the extension attributes have a higher
priority than the attributes, so there's no possibility of random
initialization orders.

Signed-off-by: Jani Nurminen <jani.nurminen@windriver.com>

Upstream-Status: Pending

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-oe/recipes-devtools/protobuf/protobuf/0001-Lower-init-prio-for-extension-attributes.patch

@@ -0,0 +1,81 @@
+From 00362d12edf1b7fde723b041a4569dc659e65ad1 Mon Sep 17 00:00:00 2001
+From: Jani Nurminen <jani.nurminen@windriver.com>
+Date: Fri, 24 Sep 2021 09:56:11 +0200
+Subject: Lower init prio for extension attributes
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Added PROTOBUF_EXTENSION_ATTRIBUTE_INIT_PRIORITY in
+code generation for extension attributes.
+It has lower prio than PROTOBUF_ATTRIBUTE_INIT_PRIORITY to
+ensure that extension attributes are initialized after
+other attribute.
+This is needed in some applications to avoid segmentation fault.
+
+Reported by Karl-Herman Näslund.
+
+Signed-off-by: Jani Nurminen <jani.nurminen@windriver.com>
+
+Upstream-Status: Pending
+
+Signed-off-by: He Zhe <zhe.he@windriver.com>
+---
+ src/google/protobuf/compiler/cpp/cpp_extension.cc | 2 +-
+ src/google/protobuf/port_def.inc                  | 7 +++++++
+ src/google/protobuf/port_undef.inc                | 1 +
+ 3 files changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/src/google/protobuf/compiler/cpp/cpp_extension.cc b/src/google/protobuf/compiler/cpp/cpp_extension.cc
+index 3792db81a..cbec19d30 100644
+--- a/src/google/protobuf/compiler/cpp/cpp_extension.cc
++++ b/src/google/protobuf/compiler/cpp/cpp_extension.cc
+@@ -174,7 +174,7 @@ void ExtensionGenerator::GenerateDefinition(io::Printer* printer) {
+   }
+ 
+   format(
+-      "PROTOBUF_ATTRIBUTE_INIT_PRIORITY "
++      "PROTOBUF_EXTENSION_ATTRIBUTE_INIT_PRIORITY "
+       "::$proto_ns$::internal::ExtensionIdentifier< $extendee$,\n"
+       "    ::$proto_ns$::internal::$type_traits$, $field_type$, $packed$ >\n"
+       "  $scoped_name$($constant_name$, $1$);\n",
+diff --git a/src/google/protobuf/port_def.inc b/src/google/protobuf/port_def.inc
+index ae9fef425..f1d203707 100644
+--- a/src/google/protobuf/port_def.inc
++++ b/src/google/protobuf/port_def.inc
+@@ -154,6 +154,9 @@
+ #ifdef PROTOBUF_ATTRIBUTE_INIT_PRIORITY
+ #error PROTOBUF_ATTRIBUTE_INIT_PRIORITY was previously defined
+ #endif
++#ifdef PROTOBUF_EXTENSION_ATTRIBUTE_INIT_PRIORITY
++#error PROTOBUF_EXTENSION_ATTRIBUTE_INIT_PRIORITY was previously defined
++#endif
+ #ifdef PROTOBUF_PRAGMA_INIT_SEG
+ #error PROTOBUF_PRAGMA_INIT_SEG was previously defined
+ #endif
+@@ -596,6 +599,10 @@
+ // Highest priority is 101. We use 102 to allow code that really wants to
+ // higher priority to still beat us.
+ #define PROTOBUF_ATTRIBUTE_INIT_PRIORITY __attribute__((init_priority((102))))
++// Some embedded systems get a segmentation fault if extension attributes are
++// initialized with higher or equal priority as other attributes. This gives
++// extension attributes high priority, but lower than other attributes.
++#define PROTOBUF_EXTENSION_ATTRIBUTE_INIT_PRIORITY __attribute__((init_priority((103))))
+ #else
+ #define PROTOBUF_ATTRIBUTE_INIT_PRIORITY
+ #endif
+diff --git a/src/google/protobuf/port_undef.inc b/src/google/protobuf/port_undef.inc
+index daef09bc4..d0c613b55 100644
+--- a/src/google/protobuf/port_undef.inc
++++ b/src/google/protobuf/port_undef.inc
+@@ -77,6 +77,7 @@
+ #undef PROTOBUF_ATTRIBUTE_WEAK
+ #undef PROTOBUF_ATTRIBUTE_NO_DESTROY
+ #undef PROTOBUF_ATTRIBUTE_INIT_PRIORITY
++#undef PROTOBUF_EXTENSION_ATTRIBUTE_INIT_PRIORITY
+ #undef PROTOBUF_PRAGMA_INIT_SEG
+ 
+ // Restore macro that may have been #undef'd in port_def.inc.
+-- 
+2.17.1
+

meta-oe/recipes-devtools/protobuf/protobuf_3.15.2.bb

@@ -17,6 +17,7 @@ SRC_URI = "git://github.com/protocolbuffers/protobuf.git;branch=master;protocol=
            file://0001-protobuf-fix-configure-error.patch \
            file://0001-Makefile.am-include-descriptor.cc-when-building-libp.patch \
            file://0001-examples-Makefile-respect-CXX-LDFLAGS-variables-fix-.patch \
+           file://0001-Lower-init-prio-for-extension-attributes.patch \
 "
 S = "${WORKDIR}/git"