Bug 2060428 - Move the remaining Rust build settings into configure r=firefox-build-system-reviewers,sergesanspaille

While we're at it, make the dependency on `CARGOFLAGS` explicit.

Differential Revision: https://phabricator.services.mozilla.com/D320786

build/moz.configure/bindgen.configure

@@ -370,3 +370,13 @@ def bindgen_cflags(base_flags, extra_flags):
 
 
 set_config("BINDGEN_SYSTEM_FLAGS", bindgen_cflags)
+
+
+# Force the target down to all bindgen callers, even those that may not
+# read BINDGEN_SYSTEM_FLAGS some way or another.
+@depends(bindgen_cflags)
+def bindgen_extra_clang_args(flags):
+    return [f for f in flags or [] if f.startswith("--target=")]
+
+
+set_config("BINDGEN_EXTRA_CLANG_ARGS", bindgen_extra_clang_args)

build/moz.configure/rust.configure

@@ -611,6 +611,9 @@ set_define("MOZ_DEBUG_RUST", debug_rust)
 option(env="RUSTFLAGS", nargs=1, help="Rust compiler flags")
 set_config("RUSTFLAGS", depends("RUSTFLAGS")(lambda flags: flags))
 
+option(env="CARGOFLAGS", nargs=1, help="Flags to pass to cargo")
+set_config("CARGOFLAGS", depends("CARGOFLAGS")(lambda flags: flags))
+
 
 # Rust compiler flags
 # ==============================================================
@@ -954,3 +957,18 @@ def clippy_wrapper(build_env, host_os_arch):
 
 
 set_config("MOZ_CARGO_CLIPPY_WRAPPER", clippy_wrapper)
+
+
+# Enable link-time optimization for release builds, but not when doing
+# cross-language LTO.
+# Never enable when sancov is enabled to work around https://github.com/rust-lang/rust/issues/90300.
+# Never enable when coverage is enabled to work around https://github.com/rust-lang/rust/issues/90045.
+set_config(
+    "RUST_LTO_ELIGIBLE",
+    True,
+    when=~developer_options
+    & ~debug_rust
+    & ~lto.rust_lto
+    & ~rust_sancov_flags
+    & ~code_coverage,
+)

config/makefiles/rust.mk

@@ -81,25 +81,15 @@ endif
 # These flags are passed via `cargo rustc` and only apply to the final rustc
 # invocation (i.e., only the top-level crate, not its dependencies).
 cargo_rustc_flags = $(CARGO_RUSTCFLAGS)
-ifndef DEVELOPER_OPTIONS
-ifndef MOZ_DEBUG_RUST
+ifdef RUST_LTO_ELIGIBLE
 # Enable link-time optimization for release builds, but not when linking
-# gkrust_gtest. And not when doing cross-language LTO.
-ifndef MOZ_LTO_RUST_CROSS
-# Never enable when sancov is enabled to work around https://github.com/rust-lang/rust/issues/90300.
-ifeq (,$(RUST_SANCOV_FLAGS))
-# Never enable when coverage is enabled to work around https://github.com/rust-lang/rust/issues/90045.
-ifndef MOZ_CODE_COVERAGE
+# gkrust_gtest.
 ifeq (,$(findstring gkrust_gtest,$(RUST_LIBRARY_FILE)))
-cargo_rustc_flags += -Clto$(if $(filter full,$(MOZ_LTO_RUST_CROSS)),=fat)
+cargo_rustc_flags += -Clto
 endif
 # We need -Cembed-bitcode=yes for all crates when using -Clto.
 RUSTFLAGS += -Cembed-bitcode=yes
 endif
-endif
-endif
-endif
-endif
 
 ifdef CARGO_INCREMENTAL
 export CARGO_INCREMENTAL
@@ -243,9 +233,7 @@ endef
 $(foreach san,ASAN TSAN UBSAN,$(eval $(call sanitizer_options,$(san))))
 endif
 
-# Force the target down to all bindgen callers, even those that may not
-# read BINDGEN_SYSTEM_FLAGS some way or another.
-export BINDGEN_EXTRA_CLANG_ARGS:=$(filter --target=%,$(BINDGEN_SYSTEM_FLAGS))
+export BINDGEN_EXTRA_CLANG_ARGS
 export CARGO_TARGET_DIR
 export RUSTFLAGS
 export RUSTC