Documenting iree_copts with a nice big warning.
diff --git a/build_tools/bazel/iree.bazelrc b/build_tools/bazel/iree.bazelrc
index 7fc9945..b90be65 100644
--- a/build_tools/bazel/iree.bazelrc
+++ b/build_tools/bazel/iree.bazelrc
@@ -145,7 +145,7 @@
build:generic_clang --copt=-Wthread-safety
build:generic_clang --copt=-Wthread-safety-beta
build:generic_clang --copt=-Wunused-comparison
-build:generic_clang --copt=-Wunused-variable
+build:generic_clang --copt=-Wno-unused-variable
build:generic_clang --copt=-Wvla
# LINT.ThenChange(https://github.com/google/iree/tree/main/build_tools/cmake/iree_copts.cmake:clang_diagnostics)
@@ -274,6 +274,26 @@
# absl forces /W3 in their copts, so we exclude them to avoid D9025
build:_msvc_base --per_file_copt=+external,-com_google_absl@/w
+# Find the source of truth for these in iree_copts.cmake.
+build:_msvc_base --copt=/DWIN32_LEAN_AND_MEAN
+build:_msvc_base --copt=/DNOMINMAX
+build:_msvc_base --copt=/D_USE_MATH_DEFINES
+build:_msvc_base --copt=/D_CRT_SECURE_NO_WARNINGS
+build:_msvc_base --copt=/D_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES
+build:_msvc_base --copt=/EHsc
+build:_msvc_base --copt=/bigobj
+
+build:_msvc_base --copt=/wd4200
+build:_msvc_base --copt=/wd4018
+build:_msvc_base --copt=/wd4146 # operator applied to unsigned type, result still unsigned
+build:_msvc_base --copt=/wd4244 # possible loss of data
+build:_msvc_base --copt=/wd4267 # initializing: possible loss of data
+build:_msvc_base --copt=/wd4005 # allow: macro redefinition
+build:_msvc_base --copt=/wd4065 # allow: switch statement contains 'default' but no 'case' labels
+build:_msvc_base --copt=/wd4141 # allow: inline used more than once
+build:_msvc_base --copt=/wd4624 # allow: destructor was implicitly defined as deleted
+build:_msvc_base --copt=/wd5105 # macro expansion producing 'defined' has undefined behavior
+
# And some more explicit disables. For some reason the `/w` on external doesn't
# work for these, maybe they come from headers?
build:_msvc_base --copt=/wd4244 # possible loss of data
@@ -282,7 +302,6 @@
build:_msvc_base --copt=/wd4267 # initializing: possible loss of data
build:_msvc_base --copt=/wd4141 # inline used more than once
# new warning with the standards-compliant preprocessor. winbase itself is not standards-compliant
-build:_msvc_base --copt=/wd5105
build:_msvc_base --per_file_copt=mkl_dnn@/wd4551 # missing argument list
build:_msvc_base --per_file_copt=mkl_dnn@/wd4068 # unknown pragma
build:_msvc_base --per_file_copt=farmhash@/wd4319 # zero extending to T of greater size
@@ -303,8 +322,6 @@
build:_msvc_base --copt=/D_CRT_SECURE_NO_WARNINGS
# TensorFlow requires the "monolithic" build mode for now on Windows.
build:_msvc_base --define framework_shared_object=false
-# Necessary for M_* math constants.
-build:_msvc_base --copt=/D_USE_MATH_DEFINES
# Workaround WinGDI.h defining `ERROR`, which conflicts with logging macros.
# Note that IREE and TensorFlow both `#undef ERROR` and define their own
diff --git a/build_tools/cmake/iree_copts.cmake b/build_tools/cmake/iree_copts.cmake
index 35425be..abe9d51 100644
--- a/build_tools/cmake/iree_copts.cmake
+++ b/build_tools/cmake/iree_copts.cmake
@@ -21,14 +21,67 @@
# By default Abseil strips string literals on mobile platforms, which means
# we cannot run IREE binaries via command-line with proper options. Turn off
# the stripping.
-# TODO: we might still want to strip when compiling IREE into Android Java apps.
+# TODO(#3814): remove ABSL flags.
if(ANDROID)
add_definitions(-DABSL_FLAGS_STRIP_NAMES=0)
endif()
#-------------------------------------------------------------------------------
-# C++ used within IREE
+# C/C++ options as used within IREE
#-------------------------------------------------------------------------------
+#
+# ██ ██ █████ ██████ ███ ██ ██ ███ ██ ██████
+# ██ ██ ██ ██ ██ ██ ████ ██ ██ ████ ██ ██
+# ██ █ ██ ███████ ██████ ██ ██ ██ ██ ██ ██ ██ ██ ███
+# ██ ███ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██
+# ███ ███ ██ ██ ██ ██ ██ ████ ██ ██ ████ ██████
+#
+# Everything here is added to *every* iree_cc_library/iree_cc_binary/etc.
+# That includes both runtime and compiler components, and these may propagate
+# out to user code interacting with either (such as custom modules).
+#
+# Be extremely judicious in the use of these flags.
+#
+# - Need to disable a warning?
+# Usually these are encountered in compiler-specific code and can be disabled
+# in a compiler-specific way. Only add global warning disables when it's clear
+# that we never want them or that they'll show up in a lot of places.
+#
+# See: https://stackoverflow.com/questions/3378560/how-to-disable-gcc-warnings-for-a-few-lines-of-code
+#
+# - Need to add a linker dependency?
+# First figure out if you *really* need it. If it's only required on specific
+# platforms and in very specific files clang or msvc are used prefer
+# autolinking. GCC is stubborn and doesn't have autolinking so additional
+# flags may be required there.
+#
+# See: https://en.wikipedia.org/wiki/Auto-linking
+#
+# - Need to tweak a compilation mode setting (debug/asserts/etc)?
+# Don't do that here, and in general *don't do that at all* unless it's behind
+# a very specific IREE-prefixed cmake flag (like IREE_SIZE_OPTIMIZED).
+# There's no one-size solution when we are dealing with cross-project and
+# cross-compiled binaries - there's no safe way to set global options that
+# won't cause someone to break, and you probably don't really need to do
+# change that setting anyway. Follow the rule of least surprise: if the user
+# has CMake's Debug configuration active then don't force things into release
+# mode, etc.
+#
+# - Need to add an include directory?
+# Don't do that here. Always prefer to fully-specify the path from the IREE
+# workspace root when it's known that the compilation will be occuring using
+# the files within the IREE checkout; for example, instead of adding a global
+# include path to third_party/foo/ and #include <foo.h>'ing, just
+# #include "third_party/foo/foo.h". This reduces build configuration, makes it
+# easier for readers to find the files, etc.
+#
+# - Still think you need to add an include directory? (system includes, etc)
+# Don't do that here, either. It's highly doubtful that every single target in
+# all of IREE (both compiler and runtime) on all platforms (both host and
+# cross-compilation targets) needs your special include directory. Add it on
+# the COPTS of the target you are using it in and, ideally, private to that
+# target (used in .c/cc files, not in a .h that leaks the include path
+# requirements to all consumers of the API).
set(IREE_CXX_STANDARD ${CMAKE_CXX_STANDARD})
@@ -97,7 +150,6 @@
"-Wthread-safety"
"-Wthread-safety-beta"
"-Wunused-comparison"
- "-Wunused-variable"
"-Wvla"
# LINT.ThenChange(https://github.com/google/iree/tree/main/build_tools/bazel/iree.bazelrc:clang_diagnostics)
@@ -111,27 +163,62 @@
"-Wno-gnu-label-as-value"
CLANG_OR_GCC
"-Wno-unused-parameter"
+ "-Wno-unused-variable"
"-Wno-undef"
"-fvisibility=hidden"
MSVC_OR_CLANG_CL
+ # Exclude a bunch of rarely-used APIs, such as crypto/DDE/shell.
+ # https://docs.microsoft.com/en-us/windows/win32/winprog/using-the-windows-headers
+ # NOTE: this is not really required anymore for build performance but does
+ # work around some issues that crop up with header version compatibility
+ # (abseil has issues with winsock versions).
"/DWIN32_LEAN_AND_MEAN"
+
+ # Don't allow windows.h to define MIN and MAX and conflict with the STL.
+ # There's no legit use for these macros as any code we are writing ourselves
+ # that we want a MIN/MAX in should be using an IREE-prefixed version
+ # instead: iree_min iree_max
+ # https://stackoverflow.com/a/4914108
+ "/DNOMINMAX"
+
+ # Adds M_PI and other constants to <math.h>/<cmath> (to match non-windows).
+ # https://docs.microsoft.com/en-us/cpp/c-runtime-library/math-constants
"/D_USE_MATH_DEFINES"
+
+ # Configure exception handling for standard C++ behavior.
+ # - /EHs enables C++ catch-style exceptions
+ # - /EHc breaks unwinding across extern C boundaries, dramatically reducing
+ # unwind table size and associated exception handling overhead as the
+ # compiler can assume no exception will ever be thrown within any function
+ # annotated with extern "C".
+ # https://docs.microsoft.com/en-us/cpp/build/reference/eh-exception-handling-model
+ #
+ # TODO(benvanik): figure out if we need /EHs - we don't use exceptions in
+ # the runtime and I'm pretty sure LLVM doesn't use them either.
+ "/EHsc"
+
+ # Default max section count is 64k, which is woefully inadequate for some of
+ # the insanely bloated tablegen outputs LLVM/MLIR produces. This cranks it
+ # up to 2^32. It's not great that we have to generate/link files like that
+ # but it's better to not get spurious failures during LTCG.
+ # https://docs.microsoft.com/en-us/cpp/build/reference/bigobj-increase-number-of-sections-in-dot-obj-file
+ "/bigobj"
+
"/wd4624"
- # 'inline': used more than once
- "/wd4141"
- # 'WIN32_LEAN_AND_MEAN': macro redefinition
- "/wd4005"
+ "/wd4141" # duplicate inline attributes
+ "/wd4005" # macro redefinition
"/wd4267"
"/wd4141"
"/wd4244"
"/wd4146"
"/wd4018"
"/wd4065"
- # TODO(benvanik): figure out if really required or accidentally enabled.
- "/EHsc"
- "/bigobj"
)
+
+# TODO(benvanik): remove the ABSL usage here; we aren't abseil.
set(IREE_DEFAULT_LINKOPTS "${ABSL_DEFAULT_LINKOPTS}")
+
+# TODO(benvanik): remove the ABSL usage here; we aren't abseil.
set(IREE_TEST_COPTS "${ABSL_TEST_COPTS}")
#-------------------------------------------------------------------------------
