compiler: add a test for #22

cogent/tests/pass_another-weird-error-in-ext2.cogent

@@ -0,0 +1,79 @@
+type ExState
+type Array a
+type WordArray a
+type VfsMountInfo
+type RR c a b = (c, <Success a | Error b>)
+type Option a = <Some a | None ()>
+type BlockOffset
+type Indirect
+type Chain
+type BlockPtr
+type OSBuffer
+
+type FsState = {
+    super                  : Ext2Superblock,
+    super_buf              : OSBuffer,
+    superblock_num         : U32,
+    group_count            : U32,
+    inode_tables_per_group : U32,
+    flags                  : U32,
+    cur_overhead           : U32,
+    group_desc_array       : Array OSBuffer,
+    prealloc_offsets       : Option (WordArray BlockOffset),   -- for Path
+    prealloc_indirects     : Option (Array Indirect),          -- for Chain
+    prealloc_chain         : Option (Chain),
+    prealloc_blockptrs     : Option (WordArray BlockPtr)       -- for block allocation
+}
+
+type Ext2Superblock = {
+    inode_count             : U32,
+    magic                   : U16
+}
+
+osbuffer_create: ExState -> RR ExState OSBuffer ()
+malloc_FsState: ExState -> RR ExState (FsState take (..)) ()
+get_superblock_num: (ExState, (Array (WordArray U8))!) -> (ExState, U32)
+osbuffer_read_block: (#{ex: ExState, buf: OSBuffer, blk: U32}) -> RR (ExState, OSBuffer) () ()
+deserialise_Ext2Superblock: (ExState, OSBuffer!, U32) -> RR ExState (Ext2Superblock, U32) ()
+
+free_Ext2Superblock  : (ExState, Ext2Superblock take (..)) -> ExState
+free_Ext2Superblock' : (ExState, Ext2Superblock) -> ExState
+free_FsState: (ExState, FsState take (..)) -> ExState
+osbuffer_destroy: (ExState, OSBuffer) -> (ExState)
+
+
+fs_mount: #{ex: ExState, options: (Array (WordArray U8))!} -> RR ExState #{state: FsState, mountinfo: #VfsMountInfo} U32
+fs_mount #{ex, options} = 
+    let (ex, res) = malloc_FsState ex
+    in res
+    | Success state_t ->
+        let (ex, res) = osbuffer_create ex
+        in res
+        | Success buf_super ->
+            let (ex, sb_num) = get_superblock_num (ex, options) !options
+            -- and state_t = state_t { superblock_num = sb_num }
+            and ((ex, buf_super), res) = osbuffer_read_block #{ex, buf = buf_super, blk = sb_num}
+            in res
+            | Success () -> 
+                let (ex, res) = deserialise_Ext2Superblock (ex, buf_super, 0) !buf_super
+                in res
+                | Success (super, _) -> 
+                    let super' = super {inode_count = 1, magic = 2}
+                    and ex = free_Ext2Superblock (ex,super')
+                    and ex = free_FsState (ex, state_t)
+                    and ex = osbuffer_destroy (ex, buf_super)
+                    in (ex, Error 1)
+                | Error () ->
+                    let ex = osbuffer_destroy (ex, buf_super)
+                    and ex = free_FsState (ex, state_t)
+                    in (ex, Error 1)
+            | Error () -> 
+                let ex = osbuffer_destroy (ex, buf_super)
+                and ex = free_FsState (ex, state_t)
+                in (ex, Error 1)
+        | Error () ->
+            let ex = free_FsState (ex, state_t)
+            in (ex, Error 1)
+    | Error () ->
+        (ex, Error 1)
+