[rust][tools] Fix Rust build example configuration handling

Improve the Rust build integration across core, applications, components, and module examples. Fix build failure propagation, target and feature handling, linker flags, example configuration semantics, and add STM32 CI attach coverage.

3 files changed, 33 insertions, 10 deletions

diff --git a/components/rust/examples/modules/SConscript b/components/rust/examples/modules/SConscript
index 98e57d1fd9..056501c057 100644
--- a/components/rust/examples/modules/SConscript
+++ b/components/rust/examples/modules/SConscript
@@ -32,6 +32,20 @@ def _has(sym: str) -> bool:
     except Exception:
         return bool(GetDepend(sym))
 
+
+MODULE_CONFIG_MAP = {
+    'example_lib': 'RT_RUST_MODULE_SIMPLE_MODULE',
+}
+
+
+def should_build_module(module_dir: str) -> bool:
+    if _has('RT_RUST_BUILD_ALL_EXAMPLES'):
+        return True
+
+    config = MODULE_CONFIG_MAP.get(os.path.basename(module_dir))
+    return bool(config and _has(config))
+
+
 def detect_target_for_dynamic_modules():
     """
     Detect the appropriate Rust target for dynamic modules.
@@ -68,7 +82,7 @@ def build_rust_module(module_dir, build_root):
         cargo_config = toml.load(f)
     
     module_name = cargo_config['package']['name']
-    
+
     # Detect target automatically based on the current configuration
     target = detect_target_for_dynamic_modules()
     print(f"Building Rust module '{module_name}' for target: {target}")
@@ -121,7 +135,12 @@ def build_rust_module(module_dir, build_root):
         return [], [], ""
 
 # Check dependencies
-if not _has('RT_RUST_BUILD_MODULES'):
+if not _has('RT_USING_MODULE') and not GetOption('clean'):
+    Return([])
+
+if not (
+    _has('RT_RUST_BUILD_MODULES') or _has('RT_RUST_BUILD_ALL_EXAMPLES')
+) and not GetOption('clean'):
     Return([])
 
 build_root = os.path.join(Dir('#').abspath, "build", "rust_modules")
@@ -142,7 +161,11 @@ else:
     modules_built = []
     for item in os.listdir(cwd):
         item_path = os.path.join(cwd, item)
-        if os.path.isdir(item_path) and os.path.exists(os.path.join(item_path, 'Cargo.toml')):
+        if (
+            os.path.isdir(item_path)
+            and os.path.exists(os.path.join(item_path, 'Cargo.toml'))
+            and should_build_module(item_path)
+        ):
             result = build_rust_module(item_path, build_root)
             if result[0]:
                 modules_built.extend(result[0])
@@ -151,9 +174,9 @@ else:
         print(f"Successfully built {len(modules_built)} Rust dynamic module(s): {', '.join(modules_built)}")
 
 group = DefineGroup(
-    'rust_modules', 
-    [], 
-    depend=['RT_RUST_BUILD_MODULES']
+    'rust_modules',
+    [],
+    depend=['RT_USING_RUST']
 )
 
-Return('group')
\ No newline at end of file
+Return('group')
diff --git a/components/rust/examples/modules/example_lib/Cargo.toml b/components/rust/examples/modules/example_lib/Cargo.toml
index e44aae2848..6a490acad8 100644
--- a/components/rust/examples/modules/example_lib/Cargo.toml
+++ b/components/rust/examples/modules/example_lib/Cargo.toml
@@ -9,4 +9,4 @@ edition = "2024"
 crate-type = ["cdylib"]
 
 [dependencies]
-rt-rust = { path = "../../.." }
\ No newline at end of file
+rt-rust = { path = "../../../core" }
\ No newline at end of file
diff --git a/components/rust/examples/modules/example_lib/src/lib.rs b/components/rust/examples/modules/example_lib/src/lib.rs
index 79fe384e6a..8b86c593cd 100644
--- a/components/rust/examples/modules/example_lib/src/lib.rs
+++ b/components/rust/examples/modules/example_lib/src/lib.rs
@@ -11,7 +11,7 @@
 /* Bring rt-rust's println! macro into scope */ 
 use rt_rust::println;
 use core::ffi::{c_char, CStr};
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn rust_mylib_println(s: *const c_char) {
     if s.is_null() {
         println!("");
@@ -24,7 +24,7 @@ pub extern "C" fn rust_mylib_println(s: *const c_char) {
     }
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn rust_mylib_add(a: usize, b: usize) -> usize {
     a + b
 }