[PATCH v2 1/2] rust: support overriding crate_name

[Alice Ryhl <aliceryhl@google.com>]

Currently you cannot filter out the crate-name argument
RUSTFLAGS_REMOVE_stem.o because the Rust filter-out invocation does not
include that particular argument. Since --crate-name is an argument that
can't be passed multiple times, this means that it's currently not
possible to override the crate name. Thus, remove the --crate-name
argument for drivers. This allows them to override the crate name using
the #![crate_name] annotation.

The --crate-name argument is kept for the crates under rust/ for
simplicity and to avoid changing many of them by adding #![crate_name].

The rust analyzer script is updated to use rustc to obtain the crate
name of the driver crates, which picks up the right name when it is
configured via #![crate_name] or not.

Note that the crate name in the python script is not actually that
important - the only place where the name actually affects anything is
in the 'deps' array which specifies an index and name for each
dependency, and determines what that dependency is called in *this*
crate. (The same crate may be called different things in each
dependency.) Since driver crates are leaf crates, this doesn't apply and
the rustc invocation only affects the 'display_name' parameter.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
 scripts/Makefile.build            | 1 -
 scripts/generate_rust_analyzer.py | 8 +++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 32e209bc7985..adc3e2d1ac78 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -332,7 +332,6 @@ rust_common_cmd = \
 	-Zcrate-attr='feature($(rust_allowed_features))' \
 	-Zunstable-options --extern pin_init --extern kernel \
 	--crate-type rlib -L $(objtree)/rust/ \
-	--crate-name $(basename $(notdir $@)) \
 	--sysroot=/dev/null \
 	--out-dir $(dir $@) --emit=dep-info=$(depfile)
 
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index f9b545104f21..d25bc3d7e719 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -194,6 +194,12 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edit
         except FileNotFoundError:
             return False
 
+    def get_crate_name(path):
+        return subprocess.check_output(
+            [os.environ["RUSTC"], "--print", "crate-name", path],
+            stdin=subprocess.DEVNULL,
+        ).decode('utf-8').strip()
+
     # Then, the rest outside of `rust/`.
     #
     # We explicitly mention the top-level folders we want to cover.
@@ -212,7 +218,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edit
 
             logging.info("Adding %s", name)
             append_crate(
-                name,
+                get_crate_name(path),
                 path,
                 ["core", "kernel", "pin_init"],
                 cfg=cfg,

-- 
2.53.0.473.g4a7958ca14-goog