turn on -Werror=extra in Bazel

Summary:
These are mostly helpful warnings but we explicitly disable two of
them that are problematic in our codebase.

We also remove -Werror=type-limits and -Werror=unused-but-set-variable
since they are both included as part of -Wextra.

Test Plan: Rely on CI.

Reviewers: alband

Subscribers:

Tasks:

Tags:

Pull Request resolved: pytorch#79327

Approved by: https://github.com/malfet

.bazelrc

@@ -60,8 +60,6 @@ build --per_file_copt=^external/@-w
 #    cache
 #  * it allows for selective overrides on individual targets since the
 #    macro-level opts will come earlier than target level overrides
-build --per_file_copt='^//.*\.(cpp|cc)$'@-Werror=type-limits
-build --per_file_copt='^//.*\.(cpp|cc)$'@-Werror=unused-but-set-variable
 
 build --per_file_copt='^//.*\.(cpp|cc)$'@-Werror=all
 # The following warnings come from -Wall. We downgrade them from error
@@ -74,6 +72,30 @@ build --per_file_copt='^//.*\.(cpp|cc)$'@-Wno-sign-compare
 # We intentionally use #pragma unroll, which is compiler specific.
 build --per_file_copt='^//.*\.(cpp|cc)$'@-Wno-error=unknown-pragmas
 
+build --per_file_copt='^//.*\.(cpp|cc)$'@-Werror=extra
+# The following warnings come from -Wextra. We downgrade them from error
+# to warnings here.
+#
+# unused-parameter-compare has a tremendous amount of violations in the
+# codebase. It will be a lot of work to fix them, just disable it for
+# now.
+build --per_file_copt='^//.*\.(cpp|cc)$'@-Wno-unused-parameter
+# missing-field-parameters has both a large number of violations in
+# the codebase, but it also is used pervasively in the Python C
+# API. There are a couple of catches though:
+# * we use multiple versions of the Python API and hence have
+#   potentially multiple different versions of each relevant
+#   struct. They may have different numbers of fields. It will be
+#   unwieldy to support multiple versions in the same source file.
+# * Python itself for many of these structs recommends only
+#   initializing a subset of the fields. We should respect the API
+#   usage conventions of our dependencies.
+#
+# Hence, we just disable this warning altogether. We may want to clean
+# up some of the clear-cut cases that could be risky, but we still
+# likely want to have this disabled for the most part.
+build --per_file_copt='^//.*\.(cpp|cc)$'@-Wno-missing-field-initializers
+
 build --per_file_copt='//:aten/src/ATen/RegisterCompositeExplicitAutograd\.cpp$'@-Wno-error=unused-function
 build --per_file_copt='//:aten/src/ATen/RegisterCompositeImplicitAutograd\.cpp$'@-Wno-error=unused-function
 build --per_file_copt='//:aten/src/ATen/RegisterMkldnnCPU\.cpp$'@-Wno-error=unused-function

tools/rules/cu.bzl

@@ -3,8 +3,6 @@ load("@rules_cuda//cuda:defs.bzl", "cuda_library")
 NVCC_COPTS = [
     "--expt-relaxed-constexpr",
     "--expt-extended-lambda",
-    "--compiler-options=-Werror=type-limits",
-    "--compiler-options=-Werror=unused-but-set-variable",
 
     "--compiler-options=-Werror=all",
     # The following warnings come from -Wall. We downgrade them from
@@ -16,6 +14,30 @@ NVCC_COPTS = [
     "--compiler-options=-Wno-sign-compare",
     # We intentionally use #pragma unroll, which is compiler specific.
     "--compiler-options=-Wno-error=unknown-pragmas",
+
+    "--compiler-options=-Werror=extra",
+    # The following warnings come from -Wextra. We downgrade them from
+    # error to warnings here.
+    #
+    # unused-parameter-compare has a tremendous amount of violations
+    # in the codebase. It will be a lot of work to fix them, just
+    # disable it for now.
+    "--compiler-options=-Wno-unused-parameter",
+    # missing-field-parameters has both a large number of violations
+    # in the codebase, but it also is used pervasively in the Python C
+    # API. There are a couple of catches though:
+    # * we use multiple versions of the Python API and hence have
+    #   potentially multiple different versions of each relevant
+    #   struct. They may have different numbers of fields. It will be
+    #   unwieldy to support multiple versions in the same source file.
+    # * Python itself for many of these structs recommends only
+    #   initializing a subset of the fields. We should respect the API
+    #   usage conventions of our dependencies.
+    #
+    # Hence, we just disable this warning altogether. We may want to
+    # clean up some of the clear-cut cases that could be risky, but we
+    # still likely want to have this disabled for the most part.
+    "-Wno-missing-field-initializers",
 ]
 
 def cu_library(name, srcs, copts = [], **kwargs):