rust: drop +SUFFIX from crate name

Allow multiple targets for the same crate name, which is useful when the
same crate is used for both the host and the build machine.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

5 files changed, 54 insertions, 1 deletions

diff --git a/docs/markdown/Rust.md b/docs/markdown/Rust.md
index 452dad6e6..67bbdec5b 100644
--- a/docs/markdown/Rust.md
+++ b/docs/markdown/Rust.md
@@ -98,3 +98,11 @@ target is a proc macro or dylib, or it depends on a dylib, in which case [`-C
 prefer-dynamic`](https://doc.rust-lang.org/rustc/codegen-options/index.html#prefer-dynamic)
 will be passed to the Rust compiler, and the standard libraries will be
 dynamically linked.
+
+## Multiple targets for the same crate name
+
+For library targets that have `rust_abi: 'rust'`, the crate name is derived from the
+target name.  First, dashes, spaces and dots are replaced with underscores.  Second,
+*since 1.10.0* anything after the first `+` is dropped.  This allows creating multiple
+targets for the same crate name, for example when the same crate is built multiple
+times with different features, or for both the build and the host machine.
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 5486b089b..13f4cdc81 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -1950,8 +1950,9 @@ class NinjaBackend(backends.Backend):
     @staticmethod
     def _get_rust_crate_name(target_name: str) -> str:
         # Rustc replaces - with _. spaces or dots are not allowed, so we replace them with underscores
+        # Also +SUFFIX is dropped, which can be used to distinguish host from build crates
         crate_name = target_name.replace('-', '_').replace(' ', '_').replace('.', '_')
-        return crate_name
+        return crate_name.split('+', 1)[0]
 
     @staticmethod
     def _get_rust_dependency_name(target: build.BuildTarget, dependency: LibTypes) -> str:
diff --git a/test cases/rust/30 both machines/lib.rs b/test cases/rust/30 both machines/lib.rs
new file mode 100644
index 000000000..432593368
--- /dev/null
+++ b/test cases/rust/30 both machines/lib.rs
@@ -0,0 +1,3 @@
+pub fn answer() -> u32 {
+    42
+}
diff --git a/test cases/rust/30 both machines/meson.build b/test cases/rust/30 both machines/meson.build
new file mode 100644
index 000000000..511518a7b
--- /dev/null
+++ b/test cases/rust/30 both machines/meson.build
@@ -0,0 +1,36 @@
+project(
+  'testproj',
+  'rust',
+  version : '0.1',
+  meson_version : '>= 1.9.0',
+  default_options : ['rust_std=2021'],
+)
+
+lib_host = static_library(
+  'lib',
+  'lib.rs',
+  rust_abi: 'rust'
+)
+
+lib_build = static_library(
+  'lib+build',
+  'lib.rs',
+  rust_abi: 'rust',
+  native: true,
+)
+
+exe_host = executable(
+  'test-host',
+  'test.rs',
+  link_with: lib_host,
+)
+
+exe_build = executable(
+  'test-build',
+  'test.rs',
+  link_with: lib_build,
+  native: true,
+)
+
+test('host', exe_host)
+test('build', exe_build)
diff --git a/test cases/rust/30 both machines/test.rs b/test cases/rust/30 both machines/test.rs
new file mode 100644
index 000000000..c9679d452
--- /dev/null
+++ b/test cases/rust/30 both machines/test.rs
@@ -0,0 +1,5 @@
+use lib::answer;
+
+fn main() {
+    println!("The answer is {}.\n", answer());
+}