runtime: get rid of config_dummy.rs. NFC.

Use the same strategy as elsewhere.

artiq/firmware/runtime/config.rs

@@ -1,3 +1,5 @@
+#[cfg(has_spiflash)]
+mod imp {
     use core::str;
     use std::btree_map::BTreeMap;
     use byteorder::{ByteOrder, BigEndian};
@@ -35,7 +37,7 @@ mod lock {
         }
     }
 
-pub use self::lock::Lock;
+    use self::lock::Lock;
 
     struct Iter<'a> {
         data:   &'a [u8],
@@ -190,3 +192,29 @@ pub fn erase() -> Result<(), ()> {
 
         Ok(())
     }
+}
+
+#[cfg(not(has_spiflash))]
+mod imp {
+    pub fn read<F: FnOnce(Result<&[u8], ()>) -> R, R>(_key: &str, f: F) -> R {
+        f(Err(()))
+    }
+
+    pub fn read_str<F: FnOnce(Result<&str, ()>) -> R, R>(_key: &str, f: F) -> R {
+        f(Err(()))
+    }
+
+    pub fn write(_key: &str, _value: &[u8]) -> Result<(), ()> {
+        Err(())
+    }
+
+    pub fn remove(_key: &str) -> Result<(), ()> {
+        Err(())
+    }
+
+    pub fn erase() -> Result<(), ()> {
+        Err(())
+    }
+}
+
+pub use self::imp::*;

artiq/firmware/runtime/config_dummy.rs

@@ -1,19 +0,0 @@
-pub fn read<F: FnOnce(Result<&[u8], ()>) -> R, R>(_key: &str, f: F) -> R {
-    f(Err(()))
-}
-
-pub fn read_str<F: FnOnce(Result<&str, ()>) -> R, R>(_key: &str, f: F) -> R {
-    f(Err(()))
-}
-
-pub fn write(_key: &str, _value: &[u8]) -> Result<(), ()> {
-    Err(())
-}
-
-pub fn remove(_key: &str) -> Result<(), ()> {
-    Err(())
-}
-
-pub fn erase() -> Result<(), ()> {
-    Err(())
-}

artiq/firmware/runtime/lib.rs

@@ -34,10 +34,7 @@ macro_rules! borrow_mut {
     })
 }
 
-#[cfg(has_spiflash)]
 mod config;
-#[cfg(not(has_spiflash))]
-#[path="config_dummy.rs"] mod config;
 mod ethmac;
 mod rtio_mgt;