[Bazel] Move C++ build-related logic into //build_defs (#9921)
These are all "toolchain-y" things, like copts, link_opts, and config_settings. These are very different from what is in //toolchain, though, so I chose the somewhat common name build_defs for the package. For now, I am only using this package for purely internal things. (Most public "defs"-type things should come from rules_proto/rules_cc, anyhow.)
diff --git a/build_defs/cpp_opts.bzl b/build_defs/cpp_opts.bzl
new file mode 100644
index 0000000..f868c4a
--- /dev/null
+++ b/build_defs/cpp_opts.bzl
@@ -0,0 +1,40 @@
+# C++ compile/link options for Protobuf.
+
+COPTS = select({
+ "//build_defs:config_msvc": [
+ "/wd4065", # switch statement contains 'default' but no 'case' labels
+ "/wd4244", # 'conversion' conversion from 'type1' to 'type2', possible loss of data
+ "/wd4251", # 'identifier' : class 'type' needs to have dll-interface to be used by clients of class 'type2'
+ "/wd4267", # 'var' : conversion from 'size_t' to 'type', possible loss of data
+ "/wd4305", # 'identifier' : truncation from 'type1' to 'type2'
+ "/wd4307", # 'operator' : integral constant overflow
+ "/wd4309", # 'conversion' : truncation of constant value
+ "/wd4334", # 'operator' : result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)
+ "/wd4355", # 'this' : used in base member initializer list
+ "/wd4506", # no definition for inline function 'function'
+ "/wd4800", # 'type' : forcing value to bool 'true' or 'false' (performance warning)
+ "/wd4996", # The compiler encountered a deprecated declaration.
+ ],
+ "//conditions:default": [
+ "-DHAVE_ZLIB",
+ "-Woverloaded-virtual",
+ "-Wno-sign-compare",
+ ],
+})
+
+# Android and MSVC builds do not need to link in a separate pthread library.
+LINK_OPTS = select({
+ "//build_defs:config_android": [],
+ "//build_defs:config_android-stlport": [],
+ "//build_defs:config_android-libcpp": [],
+ "//build_defs:config_android-gnu-libstdcpp": [],
+ "//build_defs:config_android-default": [],
+ "//build_defs:config_msvc": [
+ # Suppress linker warnings about files with no symbols defined.
+ "-ignore:4221",
+ ],
+ "//conditions:default": [
+ "-lpthread",
+ "-lm",
+ ],
+})
