bazel: Move warnings to toolchain configuration

Bug: b/240466562
Change-Id: I6e98acea7b45c8cdb32075161109a013ca4dba9f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/178557
Reviewed-by: Armando Montanez <amontanez@google.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Commit-Queue: Ted Pudlik <tpudlik@google.com>

4 files changed, 4 insertions, 15 deletions

diff --git a/pw_build/bazel.rst b/pw_build/bazel.rst
index abec75ff2..46b518d9b 100644
--- a/pw_build/bazel.rst
+++ b/pw_build/bazel.rst
@@ -12,7 +12,6 @@ Wrapper rules
 The common configuration for Bazel for all modules is in the ``pigweed.bzl``
 file. The built-in Bazel rules ``cc_binary``, ``cc_library``, and ``cc_test``
 are wrapped with ``pw_cc_binary``, ``pw_cc_library``, and ``pw_cc_test``.
-These wrappers add parameters to calls to the compiler and linker.
 
 .. _module-pw_build-bazel-pw_linker_script:
 
diff --git a/pw_build/bazel_internal/BUILD.bazel b/pw_build/bazel_internal/BUILD.bazel
index ccf02ce38..822ee7da9 100644
--- a/pw_build/bazel_internal/BUILD.bazel
+++ b/pw_build/bazel_internal/BUILD.bazel
@@ -34,6 +34,7 @@ pw_linker_script(
 cc_binary(
     name = "test_linker_script",
     srcs = ["test.cc"],
+    copts = ["-Wno-unused-variable"],
     # Only compatible with platforms that support linker scripts.
     target_compatible_with = select({
         "@platforms//os:macos": ["@platforms//:incompatible"],
@@ -53,6 +54,7 @@ cc_library(
 cc_binary(
     name = "test_transitive_linker_script",
     srcs = ["test.cc"],
+    copts = ["-Wno-unused-variable"],
     # Only compatible with platforms that support linker scripts.
     target_compatible_with = select({
         "@platforms//os:macos": ["@platforms//:incompatible"],
@@ -67,6 +69,7 @@ cc_binary(
     name = "test_direct_linker_script",
     srcs = ["test.cc"],
     additional_linker_inputs = [":linker_script_test"],
+    copts = ["-Wno-unused-variable"],
     linkopts = ["-T $(location :linker_script_test)"],
     # Only compatible with platforms that support linker scripts.
     target_compatible_with = select({
diff --git a/pw_build/bazel_internal/pigweed_internal.bzl b/pw_build/bazel_internal/pigweed_internal.bzl
index d7ce6df20..bdb79bc55 100644
--- a/pw_build/bazel_internal/pigweed_internal.bzl
+++ b/pw_build/bazel_internal/pigweed_internal.bzl
@@ -17,17 +17,6 @@
 
 load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
 
-STRICT_WARNINGS_COPTS = [
-    "-Wall",
-    "-Wextra",
-    # Make all warnings errors, except for the exemptions below.
-    "-Werror",
-    "-Wno-error=cpp",  # preprocessor #warning statement
-    "-Wno-error=deprecated-declarations",  # [[deprecated]] attribute
-]
-
-PW_DEFAULT_COPTS = STRICT_WARNINGS_COPTS
-
 KYTHE_COPTS = [
     "-Wno-unknown-warning-option",
 ]
@@ -39,7 +28,7 @@ def add_defaults(kwargs):
         kwargs: cc_* arguments to be modified.
     """
 
-    copts = PW_DEFAULT_COPTS + kwargs.get("copts", [])
+    copts = kwargs.get("copts", [])
     kwargs["copts"] = select({
         "@pigweed//pw_build:kythe": copts + KYTHE_COPTS,
         "//conditions:default": copts,
diff --git a/pw_build/pigweed.bzl b/pw_build/pigweed.bzl
index 1e793905c..d6c1cf80d 100644
--- a/pw_build/pigweed.bzl
+++ b/pw_build/pigweed.bzl
@@ -18,7 +18,6 @@ load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain", "use_c
 load("@rules_cc//cc:action_names.bzl", "C_COMPILE_ACTION_NAME")
 load(
     "//pw_build/bazel_internal:pigweed_internal.bzl",
-    "PW_DEFAULT_COPTS",
     _add_defaults = "add_defaults",
     _compile_cc = "compile_cc",
 )
@@ -262,7 +261,6 @@ def _pw_cc_blob_library_impl(ctx):
         deps = ctx.attr.deps,
         includes = [ctx.bin_dir.path + "/" + ctx.label.package],
         defines = [],
-        user_compile_flags = PW_DEFAULT_COPTS,
     )
 
 pw_cc_blob_library = rule(