Cherry-Pick protocolbuffers/protobuf#8714

Signed-off-by: Oliver Eikemeier <eikemeier@fillmore-labs.com>

.gitattributes

@@ -3,6 +3,7 @@
 *.bzl text
 *.java text
 *.json text
+*.patch text
 *.proto text
 *.yaml text
 BUILD text

README.adoc

@@ -185,20 +185,3 @@ data model naming conventions. MapStruct uses a fixed und quite unflexible acces
 so you can't really decide that protocol buffers should have one convention but Immutables another.
 Especially for Immutables we are forced to use JavaBeans-style naming convention, although this is
 not a JEE application.
-
-== Known Issues
-
-Warning during build:
-[subs="+quotes"]
-----
-[lime]#INFO:# From Compiling src/google/protobuf/descriptor.cc:
-*external/com_google_protobuf/src/google/protobuf/descriptor.cc:1038:9: [fuchsia]#warning:# passing variable 'unknown_enum_values_by_number_' by reference requires holding mutex 'unknown_enum_values_mu_' [-Wthread-safety-reference]*
-        unknown_enum_values_by_number_, std::make_pair(parent, number));
-        [lime]#^#
-*external/com_google_protobuf/src/google/protobuf/descriptor.cc:1048:9: [fuchsia]#warning:# passing variable 'unknown_enum_values_by_number_' by reference requires holding mutex 'unknown_enum_values_mu_' [-Wthread-safety-reference]*
-        unknown_enum_values_by_number_, std::make_pair(parent, number));
-        [lime]#^#
-2 warnings generated.
-----
-
-Fixed in https://github.com/protocolbuffers/protobuf/pull/8714[GitHub pull request #8714].

WORKSPACE

@@ -29,6 +29,7 @@ http_archive(
 
 http_archive(
     name = "com_google_protobuf",
+    patches = ["//patches:8714.patch"],
     sha256 = "c6003e1d2e7fefa78a3039f19f383b4f3a61e81be8c19356f85b6461998ad3db",
     strip_prefix = "protobuf-3.17.3",
     urls = ["https://github.com/protocolbuffers/protobuf/archive/v3.17.3.tar.gz"],

patches/8714.patch

@@ -0,0 +1,39 @@
+https://github.com/protocolbuffers/protobuf/pull/8714
+---
+ src/google/protobuf/stubs/mutex.h | 10 +++++++---
+ 1 file changed, 7 insertions(+), 3 deletions(-)
+
+diff --git src/google/protobuf/stubs/mutex.h src/google/protobuf/stubs/mutex.h
+index 79c9f6784..5c025b149 100644
+--- src/google/protobuf/stubs/mutex.h
++++ src/google/protobuf/stubs/mutex.h
+@@ -52,10 +52,12 @@
+   __attribute__((acquire_capability(__VA_ARGS__)))
+ #define GOOGLE_PROTOBUF_RELEASE(...) \
+   __attribute__((release_capability(__VA_ARGS__)))
++#define GOOGLE_PROTOBUF_SCOPED_CAPABILITY __attribute__((scoped_lockable))
+ #define GOOGLE_PROTOBUF_CAPABILITY(x) __attribute__((capability(x)))
+ #else
+ #define GOOGLE_PROTOBUF_ACQUIRE(...)
+ #define GOOGLE_PROTOBUF_RELEASE(...)
++#define GOOGLE_PROTOBUF_SCOPED_CAPABILITY
+ #define GOOGLE_PROTOBUF_CAPABILITY(x)
+ #endif
+
+@@ -140,10 +142,12 @@ class GOOGLE_PROTOBUF_CAPABILITY("mutex") PROTOBUF_EXPORT WrappedMutex {
+ using Mutex = WrappedMutex;
+
+ // MutexLock(mu) acquires mu when constructed and releases it when destroyed.
+-class PROTOBUF_EXPORT MutexLock {
++class GOOGLE_PROTOBUF_SCOPED_CAPABILITY PROTOBUF_EXPORT MutexLock {
+  public:
+-  explicit MutexLock(Mutex *mu) : mu_(mu) { this->mu_->Lock(); }
+-  ~MutexLock() { this->mu_->Unlock(); }
++  explicit MutexLock(Mutex *mu) GOOGLE_PROTOBUF_ACQUIRE(mu) : mu_(mu) {
++    this->mu_->Lock();
++  }
++  ~MutexLock() GOOGLE_PROTOBUF_RELEASE() { this->mu_->Unlock(); }
+  private:
+   Mutex *const mu_;
+   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MutexLock);
+--