ensure C++ standard consistency

revert #7443

it's almost impossible to predict if those headers are available. abseil has a mechanism to detect these headers, trust it. Since we are trying very hard to inject at build time the default C++ standard of the compiler or the one given in profile, it should be fine.

recipes/abseil/all/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.8)
 project(cmake_wrapper)
 
 include(conanbuildinfo.cmake)

recipes/abseil/all/conandata.yml

@@ -18,13 +18,19 @@ patches:
   "20210324.2":
     - patch_file: "patches/0003-absl-string-libm.patch"
       base_path: "source_subfolder"
+    - patch_file: "patches/0004-cpp-standard-20210324.patch"
+      base_path: "source_subfolder"
   "20200923.3":
     - patch_file: "patches/0003-absl-string-libm.patch"
       base_path: "source_subfolder"
+    - patch_file: "patches/0004-cpp-standard-20200923.patch"
+      base_path: "source_subfolder"
   "20200225.3":
     - patch_file: "patches/0001-cmake-install.patch"
       base_path: "source_subfolder"
     - patch_file: "patches/0002-missing-numeric_limits.h.patch"
       base_path: "source_subfolder"
     - patch_file: "patches/0003-absl-string-libm.patch"
       base_path: "source_subfolder"
+    - patch_file: "patches/0004-cpp-standard-20200225.patch"
+      base_path: "source_subfolder"

recipes/abseil/all/conanfile.py

@@ -7,7 +7,7 @@
 required_conan_version = ">=1.43.0"
 
 
-class AbseilRecipe(ConanFile):
+class AbseilConan(ConanFile):
     name = "abseil"
     description = "Abseil Common Libraries (C++) from Google"
     topics = ("algorithm", "container", "google", "common", "utility")
@@ -65,48 +65,17 @@ def _configure_cmake(self):
         if self._cmake:
             return self._cmake
         self._cmake = CMake(self)
-        if not tools.valid_min_cppstd(self, 11):
-            self._cmake.definitions["CMAKE_CXX_STANDARD"] = 11
         self._cmake.definitions["ABSL_ENABLE_INSTALL"] = True
+        self._cmake.definitions["ABSL_PROPAGATE_CXX_STD"] = True
         self._cmake.definitions["BUILD_TESTING"] = False
         if tools.cross_building(self):
             self._cmake.definitions["CONAN_ABSEIL_SYSTEM_PROCESSOR"] = str(self.settings.arch)
         self._cmake.configure()
         return self._cmake
 
-    @property
-    def _abseil_abi_macros(self):
-        return [
-            "ABSL_OPTION_USE_STD_ANY",
-            "ABSL_OPTION_USE_STD_OPTIONAL",
-            "ABSL_OPTION_USE_STD_STRING_VIEW",
-            "ABSL_OPTION_USE_STD_VARIANT",
-        ]
-
-    def _abseil_abi_config(self):
-        """Determine the Abseil ABI for polyfills (absl::any, absl::optional, absl::string_view, and absl::variant)"""
-        if self.settings.compiler.get_safe("cppstd"):
-            if self.settings.compiler.get_safe("cppstd") >= "17":
-                return "1"
-            return "0"
-        # As-of 2021-09-27 only GCC-11 defaults to C++17.
-        if (
-            self.settings.compiler == "gcc"
-            and tools.Version(self.settings.compiler.version) >= "11"
-        ):
-            return "1"
-        return "0"
-
     def build(self):
         for patch in self.conan_data.get("patches", {}).get(self.version, []):
             tools.patch(**patch)
-        absl_option = self._abseil_abi_config()
-        for macro in self._abseil_abi_macros:
-            tools.replace_in_file(
-                os.path.join(self._source_subfolder, "absl", "base", "options.h"),
-                "#define {} 2".format(macro),
-                "#define {} {}".format(macro, absl_option),
-            )
         cmake = self._configure_cmake()
         cmake.build()
 

recipes/abseil/all/patches/0004-cpp-standard-20200225.patch

@@ -0,0 +1,15 @@
+--- a/CMake/AbseilHelpers.cmake
++++ b/CMake/AbseilHelpers.cmake
+@@ -204,8 +204,12 @@ function(absl_cc_library)
+     endif()
+
+     # INTERFACE libraries can't have the CXX_STANDARD property set
++    if(ABSL_PROPAGATE_CXX_STD)
++        target_compile_features(${_NAME} PUBLIC cxx_std_11)
++    else()
+     set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
+     set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
++    endif()
+
+     # When being installed, we lose the absl_ prefix.  We want to put it back
+     # to have properly named lib files.  This is a no-op when we are not being

recipes/abseil/all/patches/0004-cpp-standard-20200923.patch

@@ -0,0 +1,15 @@
+--- a/CMake/AbseilHelpers.cmake
++++ b/CMake/AbseilHelpers.cmake
+@@ -206,8 +206,12 @@ function(absl_cc_library)
+     endif()
+
+     # INTERFACE libraries can't have the CXX_STANDARD property set
++    if(ABSL_PROPAGATE_CXX_STD)
++        target_compile_features(${_NAME} PUBLIC cxx_std_11)
++    else()
+     set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
+     set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
++    endif()
+
+     # When being installed, we lose the absl_ prefix.  We want to put it back
+     # to have properly named lib files.  This is a no-op when we are not being

recipes/abseil/all/patches/0004-cpp-standard-20210324.patch

@@ -0,0 +1,15 @@
+--- a/CMake/AbseilHelpers.cmake
++++ b/CMake/AbseilHelpers.cmake
+@@ -254,8 +254,12 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
+     endif()
+
+     # INTERFACE libraries can't have the CXX_STANDARD property set
++    if(ABSL_PROPAGATE_CXX_STD)
++        target_compile_features(${_NAME} PUBLIC cxx_std_11)
++    else()
+     set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD ${ABSL_CXX_STANDARD})
+     set_property(TARGET ${_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
++    endif()
+
+     # When being installed, we lose the absl_ prefix.  We want to put it back
+     # to have properly named lib files.  This is a no-op when we are not being