From 0de7a5031184c2f0023c0aea0898a16fd4641dc5 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Fri, 27 Dec 2019 19:56:19 +0000
Subject: [PATCH] Add Ast.to_shell_script.

Previously we were confusing Ast.substitute with the place where we
need to shell quote.
---
 src/ast.ml  | 39 +++++++++++++++++++++++++++++++++++++++
 src/ast.mli |  6 ++++++
 src/eval.ml |  3 ++-
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/ast.ml b/src/ast.ml
index 62af833..c828bb0 100644
--- a/src/ast.ml
+++ b/src/ast.ml
@@ -112,6 +112,45 @@ and substitute env loc substs =
   ) substs;
   Buffer.contents b
 
+let rec to_shell_script env loc substs =
+  let b = Buffer.create 13 in
+  List.iter (
+    function
+    | SString s -> Buffer.add_string b s
+    | SVar name ->
+       let expr = getvar env loc name in
+       let s = expr_to_shell_string env expr in
+       Buffer.add_string b s
+  ) substs;
+  Buffer.contents b
+
+and expr_to_shell_string env = function
+  | EConstant (loc, CString s) -> Filename.quote s
+
+  | EVar (loc, name) ->
+     let expr = getvar env loc name in
+     expr_to_shell_string env expr
+
+  | ESubsts (loc, str) ->
+     Filename.quote (substitute env loc str)
+
+  | EList (loc, exprs) ->
+     let strs = List.map (expr_to_shell_string env) exprs in
+     (* These are shell quoted so we can just concat them with space. *)
+     String.concat " " strs
+
+  | ECall (loc, name, _) ->
+     failwithf "%a: cannot use goal ‘%s’ in shell expansion"
+       string_loc loc name
+
+  (* Tactics expand to the first parameter. *)
+  | ETactic (loc, _, []) -> Filename.quote ""
+  | ETactic (loc, _, (arg :: _)) -> expr_to_shell_string env arg
+
+  | EGoal (loc, _) ->
+     failwithf "%a: cannot use goal in shell expansion"
+       string_loc loc
+
 module Substs = struct
   type t = {
       mutable elems : subst list; (* built in reverse order *)
diff --git a/src/ast.mli b/src/ast.mli
index 978099e..9bb2c9a 100644
--- a/src/ast.mli
+++ b/src/ast.mli
@@ -90,6 +90,12 @@ val to_constant : env -> expr -> constant
     raises [Failure _]. *)
 val substitute : env -> loc -> substs -> string
 
+(** Similar to {!substitute} except this is used where we will
+    pass the result immediately to the shell to execute.  Variables
+    are substituted with shell quoted strings.  Raises [Failure _]
+    on error. *)
+val to_shell_script : env -> loc -> substs -> string
+
 (** This is used for incrementally building Ast.substs in the parser. *)
 module Substs : sig
   type t
diff --git a/src/eval.ml b/src/eval.ml
index c6cbda1..f03e0e4 100644
--- a/src/eval.ml
+++ b/src/eval.ml
@@ -101,7 +101,8 @@ and needs_rebuild env loc name deps pattern =
   match pattern with
   | Ast.PTactic (loc, tactic, targs) ->
      (* Resolve the targs down to constants. *)
-     let targs = List.map (Ast.substitute env loc) targs in
+     let targs = List.map ((* XXX Ast.to_shell_script *)
+                            Ast.substitute env loc) targs in
      (* XXX Look up the tactic.
       * We would do that, but for now hard code the *file tactic. XXX
       *)
-- 
1.8.3.1