[C/C++] Add GCC 11 to the build matrix (aeron-io#1214)

* [CMake] Add `-Wno-error=maybe-uninitialized` to teh compiler flags to allow compiling on gcc 11 with Googletest 1.10.0.

* [CI] Add gcc 11 to the build matrix.

* [CMake] Add GoogleTest dependency directly from the repo as it now follows 'Live at HEAD' philosophy and there will no longer be any releases + the upgrade is necessary for gcc 11 compatibility.

* Revert "[CMake] Add `-Wno-error=maybe-uninitialized` to teh compiler flags to allow compiling on gcc 11 with Googletest 1.10.0."

This reverts commit d1277b4.

* Revert "Revert "[CMake] Add `-Wno-error=maybe-uninitialized` to teh compiler flags to allow compiling on gcc 11 with Googletest 1.10.0.""

This reverts commit c2a90e1.

* [CMake] Add `-Wno-error=maybe-uninitialized` for GCC 11 if it is before 11.2 release.

* Revert "[CMake] Add GoogleTest dependency directly from the repo as it now follows 'Live at HEAD' philosophy and there will no longer be any releases + the upgrade is necessary for gcc 11 compatibility."

This reverts commit 9d9c7c1.

* [CMake] Fix end of the block.

* [CI] Use `impish` repo to install GCC 11.2 or higher.

* Revert "[CI] Use `impish` repo to install GCC 11.2 or higher."

This reverts commit 9895b7c.

* [CMake] Add `-Wno-error=maybe-uninitialized` for GCC 11 or higher. This is needed, because otherwise GoogleTest won't compile.

.github/workflows/ci-low-cadence.yml

@@ -79,7 +79,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [ '10' ]
+        version: [ '11' ]
     env:
       CC: gcc-${{ matrix.version }}
       CXX: g++-${{ matrix.version }}
@@ -237,7 +237,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [ '10' ]
+        version: [ '11' ]
     env:
       CC: gcc-${{ matrix.version }}
       CXX: g++-${{ matrix.version }}

.github/workflows/ci.yml

@@ -143,7 +143,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [ '6', '7', '8', '9', '10' ]
+        version: [ '6', '7', '8', '9', '10', '11' ]
     env:
       CC: gcc-${{ matrix.version }}
       CXX: g++-${{ matrix.version }}

CMakeLists.txt

@@ -161,6 +161,10 @@ add_definitions(-DAERON_VERSION_PATCH=${aeron_VERSION_PATCH})
 if (UNIX)
     add_compile_options(-Wall -Wpedantic -Wextra -Wno-unused-parameter)
 
+    if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER "11.0")
+        add_compile_options(-Wno-error=maybe-uninitialized)
+    endif ()
+
     if (C_WARNINGS_AS_ERRORS)
         add_compile_options($<$<COMPILE_LANGUAGE:C>:-Werror>)
     endif (C_WARNINGS_AS_ERRORS)