+let rec to_constant env = function
+ | Ast.EConstant (loc, c) -> c
+
+ | EVar (loc, name) ->
+ let expr = Ast.getvar env loc name in
+ to_constant env expr
+
+ | ESubsts (loc, str) ->
+ CString (substitute env loc str)
+
+ | EList (loc, _) ->
+ failwithf "%a: list found where constant expression expected"
+ Ast.string_loc loc
+
+ | ECall (loc, name, args) ->
+ let expr = Ast.getvar env loc name in
+ (match expr with
+ | EGoalDefn _ ->
+ (* Goals don't return anything so they cannot be used in
+ * constant expressions. Use a function instead.
+ *)
+ failwithf "%a: cannot use goal call ‘%s’ in shell expansion"
+ Ast.string_loc loc name
+
+ | EFuncDefn (loc, func) ->
+ to_constant env (call_function env loc name args func)
+
+ | _ ->
+ failwithf "%a: cannot use ‘%s’ in constant expression"
+ Ast.string_loc loc name
+ )
+
+ | ETacticCtor (loc, name, _) ->
+ failwithf "%a: cannot use tactic ‘%s’ in constant expression"
+ Ast.string_loc loc name
+
+ | EGoalDefn (loc, _) ->
+ failwithf "%a: cannot use goal in constant expression"
+ Ast.string_loc loc
+
+ | EFuncDefn (loc, _) ->
+ failwithf "%a: cannot use function in constant expression"
+ Ast.string_loc loc
+
+ | ETacticDefn (loc, _) ->
+ failwithf "%a: cannot use tactic in constant expression"
+ Ast.string_loc loc
+
+and substitute env loc substs =
+ let b = Buffer.create 13 in
+ List.iter (
+ function
+ | Ast.SString s -> Buffer.add_string b s
+ | SVar name ->
+ let expr = Ast.getvar env loc name in
+ match to_constant env expr with
+ | Ast.CString s -> Buffer.add_string b s
+ ) substs;
+ Buffer.contents b
+
+and to_shell_script env loc substs =
+ let b = Buffer.create 13 in
+ List.iter (
+ function
+ | Ast.SString s -> Buffer.add_string b s
+ | SVar name ->
+ let expr = Ast.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
+ | Ast.EConstant (loc, CString s) -> Filename.quote s
+
+ | EVar (loc, name) ->
+ let expr = Ast.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, args) ->
+ let expr = Ast.getvar env loc name in
+ (match expr with
+ | EGoalDefn _ ->
+ (* Goals don't return anything so they cannot be used in
+ * shell script expansions. Use a function instead.
+ *)
+ failwithf "%a: cannot use goal call ‘%s’ in shell expansion"
+ Ast.string_loc loc name
+
+ | EFuncDefn (loc, func) ->
+ expr_to_shell_string env (call_function env loc name args func)
+
+ | _ ->
+ failwithf "%a: cannot call ‘%s’ which is not a function"
+ Ast.string_loc loc name
+ )
+
+ (* Tactics expand to the first parameter. *)
+ | ETacticCtor (loc, _, []) -> Filename.quote ""
+ | ETacticCtor (loc, _, (arg :: _)) -> expr_to_shell_string env arg