Add a test for "assume" annotation dropped without warning

Author: gretay-js

tests/backend/checkmach/test_assume_fail.ml

@@ -93,3 +93,26 @@ let[@zero_alloc strict] test68 x =
    carries the "assume" information of operations that were optimized away.
    So far, we haven't seen the need for it in a real example.
 *)
+
+(* CR gyorsh: the check passes on g0 and fails on g1-g3 below, even though the
+   generated code is exactly the same in all four cases.  The difference is because
+   "assume" is not propagated on partial applications. There is no misplaced
+   attribute warning. This is the same behavior as for "@inlined" annotations.
+*)
+let[@inline never][@local never] f x y = (x,y)
+
+let[@zero_alloc] g0 () =
+  let x = (f[@zero_alloc assume]) () () in
+  x
+
+let[@zero_alloc] g1 () =
+  let x = ((f[@zero_alloc assume]) ()) () in
+  x
+
+let[@zero_alloc] g2 () =
+  let x = ((f ())[@zero_alloc assume]) () in
+  x
+
+let[@zero_alloc] g3 () =
+  let x = (((f[@zero_alloc assume]) ())[@zero_alloc assume]) () in
+  x

tests/backend/checkmach/test_assume_fail.output

@@ -48,3 +48,21 @@ Error: Annotation check for zero_alloc strict failed on function Test_assume_fai
 
 File "test_assume_fail.ml", line 85, characters 5-9:
 Error: allocation of 24 bytes
+
+File "test_assume_fail.ml", line 108, characters 5-15:
+Error: Annotation check for zero_alloc failed on function Test_assume_fail.g1 (camlTest_assume_fail.g1_HIDE_STAMP)
+
+File "test_assume_fail.ml", line 109, characters 10-41:
+Error: called function may allocate (direct tailcall camlTest_assume_fail.f_HIDE_STAMP)
+
+File "test_assume_fail.ml", line 112, characters 5-15:
+Error: Annotation check for zero_alloc failed on function Test_assume_fail.g2 (camlTest_assume_fail.g2_HIDE_STAMP)
+
+File "test_assume_fail.ml", line 113, characters 10-41:
+Error: called function may allocate (direct tailcall camlTest_assume_fail.f_HIDE_STAMP)
+
+File "test_assume_fail.ml", line 116, characters 5-15:
+Error: Annotation check for zero_alloc failed on function Test_assume_fail.g3 (camlTest_assume_fail.g3_HIDE_STAMP)
+
+File "test_assume_fail.ml", line 117, characters 10-63:
+Error: called function may allocate (direct tailcall camlTest_assume_fail.f_HIDE_STAMP)