rust: pass rpath arguments to rustdoc --test

rustdoc does not support --print, and therefore the rpath argument corresponding
to the rust installation is not passed to doctests.

Forward anything that requires --print to the RustCompiler, thus fixing
doctests with a shared library dependency.

Fixes: #14813
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 27 insertions, 1 deletions

diff --git a/mesonbuild/compilers/rust.py b/mesonbuild/compilers/rust.py
index b72f6b0..aef88eb 100644
--- a/mesonbuild/compilers/rust.py
+++ b/mesonbuild/compilers/rust.py
@@ -341,7 +341,7 @@ class RustCompiler(Compiler):
 
         return RustdocTestCompiler(exelist, self.version, self.for_machine,
                                    self.is_cross, self.info, full_version=self.full_version,
-                                   linker=self.linker)
+                                   linker=self.linker, rustc=self)
 
 class ClippyRustCompiler(RustCompiler):
 
@@ -361,6 +361,26 @@ class RustdocTestCompiler(RustCompiler):
 
     id = 'rustdoc --test'
 
+    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice,
+                 is_cross: bool, info: 'MachineInfo',
+                 full_version: T.Optional[str],
+                 linker: T.Optional['DynamicLinker'], rustc: RustCompiler):
+        super().__init__(exelist, version, for_machine,
+                         is_cross, info, full_version, linker)
+        self.rustc = rustc
+
+    @functools.lru_cache(maxsize=None)
+    def get_sysroot(self) -> str:
+        return self.rustc.get_sysroot()
+
+    @functools.lru_cache(maxsize=None)
+    def get_target_libdir(self) -> str:
+        return self.rustc.get_target_libdir()
+
+    @functools.lru_cache(maxsize=None)
+    def get_cfgs(self) -> T.List[str]:
+        return self.rustc.get_cfgs()
+
     def get_debug_args(self, is_debug: bool) -> T.List[str]:
         return []
 
diff --git a/test cases/rust/9 unit tests/meson.build b/test cases/rust/9 unit tests/meson.build
index 0fa2fa8..81045f2 100644
--- a/test cases/rust/9 unit tests/meson.build
+++ b/test cases/rust/9 unit tests/meson.build
@@ -40,6 +40,12 @@ if rustdoc.found()
     protocol : 'rust',
     suite : ['doctests'],
   )
+
+  doclib = shared_library('rust_doc_lib', ['doctest1.rs'], build_by_default : false)
+  rust.doctest('rust shared doctests', doclib,
+    protocol : 'rust',
+    suite : ['doctests'],
+  )
 endif
 
 exe = executable('rust_exe', ['test2.rs', 'test.rs'], build_by_default : false)