From b320d432591b899d39e40d013b79012e0be2ebab Mon Sep 17 00:00:00 2001
From: Milo Davis <davis.mil@husky.neu.edu>
Date: Thu, 20 Jul 2017 15:51:07 +0200
Subject: [PATCH] Michelson: removes NOP instruction from surface syntax

---
 src/proto/alpha/docs/json-notations.md  | 1 -
 src/proto/alpha/docs/language.md        | 1 -
 src/proto/alpha/script_interpreter.ml   | 2 +-
 src/proto/alpha/script_ir_translator.ml | 7 ++-----
 4 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/src/proto/alpha/docs/json-notations.md b/src/proto/alpha/docs/json-notations.md
index 6e54ce317..ce5f0a44a 100644
--- a/src/proto/alpha/docs/json-notations.md
+++ b/src/proto/alpha/docs/json-notations.md
@@ -133,7 +133,6 @@ with the following JSON script description.
       | "EXEC"
       | { "DIP": [ [ /* instruction */ ... ] ] }
       | "FAIL"
-      | "NOP"
       | "CONCAT"
       | "ADD"
       | "SUB"
diff --git a/src/proto/alpha/docs/language.md b/src/proto/alpha/docs/language.md
index 4e96e8be4..11f9ecb0c 100644
--- a/src/proto/alpha/docs/language.md
+++ b/src/proto/alpha/docs/language.md
@@ -1810,7 +1810,6 @@ X - Full grammar
       | EXEC
       | DIP { <instruction> ... }
       | FAIL
-      | NOP
       | CONCAT
       | ADD
       | SUB
diff --git a/src/proto/alpha/script_interpreter.ml b/src/proto/alpha/script_interpreter.ml
index c5d644e62..a213be702 100644
--- a/src/proto/alpha/script_interpreter.ml
+++ b/src/proto/alpha/script_interpreter.ml
@@ -333,7 +333,7 @@ let rec interp
           | Fail, _ ->
               fail (Reject loc)
           | Nop, stack ->
-              logged_return (stack, qta - 1, ctxt)
+              logged_return (stack, qta, ctxt)
           (* comparison *)
           | Compare Bool_key, Item (a, Item (b, rest)) ->
               let cmpres = Compare.Bool.compare a b in
diff --git a/src/proto/alpha/script_ir_translator.ml b/src/proto/alpha/script_ir_translator.ml
index 0c43a4e8f..906760d6d 100644
--- a/src/proto/alpha/script_ir_translator.ml
+++ b/src/proto/alpha/script_ir_translator.ml
@@ -1041,9 +1041,6 @@ and parse_instr
       bef ->
         let descr aft = { loc ; instr = Fail ; bef ; aft } in
         return (Failed { descr })
-    | Prim (loc, "NOP", []),
-      stack ->
-        return (typed loc (Nop, stack))
     (* timestamp operations *)
     | Prim (loc, "ADD", []),
       Item_t (Timestamp_t, Item_t (Int_t kind, rest)) ->
@@ -1290,7 +1287,7 @@ and parse_instr
     | Prim (loc, ("DROP" | "DUP" | "SWAP" | "SOME" | "UNIT"
                  | "PAIR" | "CAR" | "CDR" | "CONS"
                  | "MEM" | "UPDATE" | "MAP" | "REDUCE"
-                 | "GET" | "EXEC" | "FAIL" | "NOP"
+                 | "GET" | "EXEC" | "FAIL"
                  | "CONCAT" | "ADD" | "SUB"
                  | "MUL" | "DIV" | "MOD" | "OR" | "AND" | "XOR"
                  | "NOT" | "CHECKED_ABS" | "CHECKED_NEG"
@@ -1362,7 +1359,7 @@ and parse_instr
           [ "DROP" ; "DUP" ; "SWAP" ; "SOME" ; "UNIT" ;
             "PAIR" ; "CAR" ; "CDR" ; "CONS" ;
             "MEM" ; "UPDATE" ; "MAP" ; "REDUCE" ;
-            "GET" ; "EXEC" ; "FAIL" ; "NOP" ;
+            "GET" ; "EXEC" ; "FAIL" ;
             "CONCAT" ; "ADD" ; "SUB" ;
             "MUL" ; "DIV" ; "MOD" ; "OR" ; "AND" ; "XOR" ;
             "NOT" ; "CHECKED_ABS" ; "CHECKED_NEG" ;