[meta-lts-mixins][scarthgap/rust][PATCH 35/35] classes/cargo: remove BUILD_MODE, replace with CARGO_PROFILE

From: Ross Burton <[email protected]>

The BUILD_MODE variable appears to be a way to select the Cargo build profile
that is used, but it can't be assigned because it and other pieces of
code base their logic on the value of DEBUG_BUILD.

Instead of a BUILD_MODE variable that is "--release" or "" depending on
the value of DEBUG_BUILD, replace it with a clear CARGO_PROFILE variable
that selects the profile to use. The default has the same behaviour as before:
either "release" or "dev" based on DEBUG_BUILD.

This profile is then passed to cargo, and used to construct paths in the
build tree (with the caveat that the "dev" profile puts files in "debug").

[1] https://doc.rust-lang.org/cargo/reference/profiles.html

Signed-off-by: Ross Burton <[email protected]>
Signed-off-by: Mathieu Dubois-Briand <[email protected]>
Signed-off-by: Richard Purdie <[email protected]>
(adapted from oe-core commit d4de7d0256aca47cdb1df48640c37221deaa09d4)
Signed-off-by: Scott Murray <[email protected]>
---
 classes-recipe/cargo.bbclass | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/classes-recipe/cargo.bbclass b/classes-recipe/cargo.bbclass
index 8e05a82..b34f3ce 100644
--- a/classes-recipe/cargo.bbclass
+++ b/classes-recipe/cargo.bbclass
@@ -31,18 +31,28 @@ B = "${WORKDIR}/build"
 export RUST_BACKTRACE = "1"
 
 RUSTFLAGS ??= ""
-BUILD_MODE = "${@['--release', ''][d.getVar('DEBUG_BUILD') == '1']}"
+
+# The cargo profile to use. Defaults to release or dev based on DEBUG_BUILD, but
+# can be set to any valid profile.
+# https://doc.rust-lang.org/cargo/reference/profiles.html
+CARGO_PROFILE ?= "${@oe.utils.vartrue('DEBUG_BUILD', 'dev', 'release', d)}"
+
 # --frozen flag will prevent network access (which is required since only
 # the do_fetch step is authorized to access network)
 # and will require an up to date Cargo.lock file.
 # This force the package being built to already ship a Cargo.lock, in the end
 # this is what we want, at least, for reproducibility of the build.
-CARGO_BUILD_FLAGS = "-v --frozen --target ${RUST_HOST_SYS} ${BUILD_MODE} --manifest-path=${CARGO_MANIFEST_PATH}"
+CARGO_BUILD_FLAGS = "-v --frozen --target ${RUST_HOST_SYS} --profile=${CARGO_PROFILE} --manifest-path=${CARGO_MANIFEST_PATH}"
+
+# The build directory is named after the profile, apart from the dev profile
+# which uses 'debug'.
+def cargo_build_directory(d):
+    profile = d.getVar("CARGO_PROFILE")
+    return "debug" if profile == "dev" else profile
+BUILD_DIR = "${@cargo_build_directory(d)}"
 
-# This is based on the content of CARGO_BUILD_FLAGS and generally will need to
-# change if CARGO_BUILD_FLAGS changes.
-BUILD_DIR = "${@['release', 'debug'][d.getVar('DEBUG_BUILD') == '1']}"
 CARGO_TARGET_SUBDIR = "${RUST_HOST_SYS}/${BUILD_DIR}"
+
 oe_cargo_build () {
 	export RUSTFLAGS="${RUSTFLAGS}"
 	bbnote "Using rust targets from ${RUST_TARGET_PATH}"
-- 
2.55.0