From b1d0dde88112316ff14c352b4f48d643bb946e7c Mon Sep 17 00:00:00 2001
From: Xavier Claessens <xavier.claessens@collabora.com>
Date: Thu, 2 Nov 2023 11:28:57 -0400
Subject: [PATCH] rust: proc-macro transitive dependencies should be ignored

Fixes: #12459
---
 mesonbuild/build.py                             |  2 ++
 .../rust/20 transitive dependencies/foo.c       |  6 ++++++
 .../rust/20 transitive dependencies/foo.rs      |  9 +++++++++
 .../rust/20 transitive dependencies/meson.build | 17 ++++++++++++++++-
 .../rust/20 transitive dependencies/proc.rs     |  7 +++++++
 5 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 test cases/rust/20 transitive dependencies/foo.c
 create mode 100644 test cases/rust/20 transitive dependencies/foo.rs
 create mode 100644 test cases/rust/20 transitive dependencies/proc.rs

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 8ae54754b639..9283bca97f96 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -1299,6 +1299,8 @@ def get_dependencies_recurse(self, result: OrderedSet[Target], include_internals
         for t in self.link_targets:
             if t in result:
                 continue
+            if isinstance(t, SharedLibrary) and t.rust_crate_type == 'proc-macro':
+                continue
             if include_internals or not t.is_internal():
                 result.add(t)
             if isinstance(t, StaticLibrary):
diff --git a/test cases/rust/20 transitive dependencies/foo.c b/test cases/rust/20 transitive dependencies/foo.c
new file mode 100644
index 000000000000..81b7f5c350be
--- /dev/null
+++ b/test cases/rust/20 transitive dependencies/foo.c	
@@ -0,0 +1,6 @@
+int foo_rs(void);
+
+int main(void)
+{
+    return foo_rs() == 42 ? 0 : 1;
+}
diff --git a/test cases/rust/20 transitive dependencies/foo.rs b/test cases/rust/20 transitive dependencies/foo.rs
new file mode 100644
index 000000000000..8e3863853f9d
--- /dev/null
+++ b/test cases/rust/20 transitive dependencies/foo.rs	
@@ -0,0 +1,9 @@
+extern crate pm;
+use pm::make_answer;
+
+make_answer!();
+
+#[no_mangle]
+pub fn foo_rs() -> u32 {
+    answer()
+}
diff --git a/test cases/rust/20 transitive dependencies/meson.build b/test cases/rust/20 transitive dependencies/meson.build
index 2f378f88fecd..c1ce821c87ce 100644
--- a/test cases/rust/20 transitive dependencies/meson.build	
+++ b/test cases/rust/20 transitive dependencies/meson.build	
@@ -1,4 +1,4 @@
-project('transitive dependencies', 'rust',
+project('transitive dependencies', 'rust', 'c',
   version : '1.0.0',
   meson_version : '>= 1.0.0',
   default_options : ['rust_std=2018'],
@@ -10,3 +10,18 @@ subdir('libb')
 main = executable('main', 'main.rs',
   dependencies : [libb_dep],
 )
+
+# Since foo-rs is a static library, its dependencies are normally added to foo
+# library linker. However, since pm is a proc-macro, foo library should not
+# link with it. In native build this is an harmless overlinking, but in cross
+# building foo and pm are for different arch and it would fail to link.
+rust = import('rust')
+pm = rust.proc_macro('pm', 'proc.rs')
+foo = static_library('foo-rs', 'foo.rs',
+  rust_abi: 'c',
+  link_with: pm,
+)
+exe = executable('footest', 'foo.c',
+  link_with: foo,
+)
+test('footest', exe)
diff --git a/test cases/rust/20 transitive dependencies/proc.rs b/test cases/rust/20 transitive dependencies/proc.rs
new file mode 100644
index 000000000000..53935e45d17f
--- /dev/null
+++ b/test cases/rust/20 transitive dependencies/proc.rs	
@@ -0,0 +1,7 @@
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn make_answer(_item: TokenStream) -> TokenStream {
+    "fn answer() -> u32 { 42 }".parse().unwrap()
+}