Support Rust targets with more than one source file. Closes #3632.

4 files changed, 20 insertions, 3 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 401ad19..a773439 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -1258,11 +1258,17 @@ int dummy;
 
     def generate_rust_target(self, target, outfile):
         rustc = target.compilers['rust']
-        relsrc = []
+        # Rust compiler takes only the main file as input and
+        # figures out what other files are needed via import
+        # statements and magic.
+        main_rust_file = None
         for i in target.get_sources():
             if not rustc.can_compile(i):
                 raise InvalidArguments('Rust target %s contains a non-rust source file.' % target.get_basename())
-            relsrc.append(i.rel_to_builddir(self.build_to_src))
+            if main_rust_file is None:
+                main_rust_file = i.rel_to_builddir(self.build_to_src)
+        if main_rust_file is None:
+            raise RuntimeError('A Rust target has no Rust sources. This is weird. Also a bug. Please report')
         target_name = os.path.join(target.subdir, target.get_filename())
         args = ['--crate-type']
         if isinstance(target, build.Executable):
@@ -1329,7 +1335,7 @@ int dummy;
         if target.is_cross:
             crstr = '_CROSS'
         compiler_name = 'rust%s_COMPILER' % crstr
-        element = NinjaBuildElement(self.all_outputs, target_name, compiler_name, relsrc)
+        element = NinjaBuildElement(self.all_outputs, target_name, compiler_name, main_rust_file)
         if len(orderdeps) > 0:
             element.add_orderdep(orderdeps)
         element.add_item('ARGS', args)
diff --git a/test cases/rust/8 many files/foo.rs b/test cases/rust/8 many files/foo.rs
new file mode 100644
index 0000000..0899dc0
--- /dev/null
+++ b/test cases/rust/8 many files/foo.rs
@@ -0,0 +1,3 @@
+pub fn bar() -> () {
+    println!("Hello, world!");
+}
diff --git a/test cases/rust/8 many files/main.rs b/test cases/rust/8 many files/main.rs
new file mode 100644
index 0000000..3ffeee2
--- /dev/null
+++ b/test cases/rust/8 many files/main.rs
@@ -0,0 +1,5 @@
+mod foo;
+
+fn main() {
+    foo::bar();
+}
diff --git a/test cases/rust/8 many files/meson.build b/test cases/rust/8 many files/meson.build
new file mode 100644
index 0000000..1d906b3
--- /dev/null
+++ b/test cases/rust/8 many files/meson.build
@@ -0,0 +1,3 @@
+project('manyfiles', 'rust')
+
+test('manyfiles', executable('manyfiles', 'main.rs', 'foo.rs'))