From 1f81887a7863545d8b89bff6cc7d31941da0abf0 Mon Sep 17 00:00:00 2001
From: Vexu <git@vexu.eu>
Date: Wed, 13 May 2020 23:35:58 +0300
Subject: [PATCH] recover after invalid inline/extern

---
 lib/std/zig/ast.zig         |  4 ++++
 lib/std/zig/parse.zig       | 17 ++++++++++-------
 lib/std/zig/parser_test.zig | 15 +++++++++++++++
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/lib/std/zig/ast.zig b/lib/std/zig/ast.zig
index afb7fce23e..26bff31bbd 100644
--- a/lib/std/zig/ast.zig
+++ b/lib/std/zig/ast.zig
@@ -129,6 +129,7 @@ pub const Error = union(enum) {
     ExpectedStatement: ExpectedStatement,
     ExpectedVarDeclOrFn: ExpectedVarDeclOrFn,
     ExpectedVarDecl: ExpectedVarDecl,
+    ExpectedFn: ExpectedFn,
     ExpectedReturnType: ExpectedReturnType,
     ExpectedAggregateKw: ExpectedAggregateKw,
     UnattachedDocComment: UnattachedDocComment,
@@ -179,6 +180,7 @@ pub const Error = union(enum) {
             .ExpectedStatement => |*x| return x.render(tokens, stream),
             .ExpectedVarDeclOrFn => |*x| return x.render(tokens, stream),
             .ExpectedVarDecl => |*x| return x.render(tokens, stream),
+            .ExpectedFn => |*x| return x.render(tokens, stream),
             .ExpectedReturnType => |*x| return x.render(tokens, stream),
             .ExpectedAggregateKw => |*x| return x.render(tokens, stream),
             .UnattachedDocComment => |*x| return x.render(tokens, stream),
@@ -231,6 +233,7 @@ pub const Error = union(enum) {
             .ExpectedStatement => |x| return x.token,
             .ExpectedVarDeclOrFn => |x| return x.token,
             .ExpectedVarDecl => |x| return x.token,
+            .ExpectedFn => |x| return x.token,
             .ExpectedReturnType => |x| return x.token,
             .ExpectedAggregateKw => |x| return x.token,
             .UnattachedDocComment => |x| return x.token,
@@ -280,6 +283,7 @@ pub const Error = union(enum) {
     pub const ExpectedStatement = SingleTokenError("Expected statement, found '{}'");
     pub const ExpectedVarDeclOrFn = SingleTokenError("Expected variable declaration or function, found '{}'");
     pub const ExpectedVarDecl = SingleTokenError("Expected variable declaration, found '{}'");
+    pub const ExpectedFn = SingleTokenError("Expected function, found '{}'");
     pub const ExpectedReturnType = SingleTokenError("Expected 'var' or return type expression, found '{}'");
     pub const ExpectedAggregateKw = SingleTokenError("Expected '" ++ Token.Id.Keyword_struct.symbol() ++ "', '" ++ Token.Id.Keyword_union.symbol() ++ "', or '" ++ Token.Id.Keyword_enum.symbol() ++ "', found '{}'");
     pub const ExpectedEqOrSemi = SingleTokenError("Expected '=' or ';', found '{}'");
diff --git a/lib/std/zig/parse.zig b/lib/std/zig/parse.zig
index d8d1d4b427..cbd5336ca2 100644
--- a/lib/std/zig/parse.zig
+++ b/lib/std/zig/parse.zig
@@ -360,15 +360,17 @@ fn parseTopLevelDecl(arena: *Allocator, it: *TokenIterator, tree: *Tree) Error!?
         try tree.errors.push(.{
             .ExpectedSemiOrLBrace = .{ .token = it.index },
         });
-        return null;
+        return error.ParseError;
     }
 
     if (extern_export_inline_token) |token| {
         if (tree.tokens.at(token).id == .Keyword_inline or
             tree.tokens.at(token).id == .Keyword_noinline)
         {
-            putBackToken(it, token);
-            return null;
+            try tree.errors.push(.{
+                .ExpectedFn = .{ .token = it.index },
+            });
+            return error.ParseError;
         }
     }
 
@@ -399,10 +401,11 @@ fn parseTopLevelDecl(arena: *Allocator, it: *TokenIterator, tree: *Tree) Error!?
     }
 
     if (extern_export_inline_token) |token| {
-        if (lib_name) |string_literal_node|
-            putBackToken(it, string_literal_node.cast(Node.StringLiteral).?.token);
-        putBackToken(it, token);
-        return null;
+        try tree.errors.push(.{
+            .ExpectedVarDeclOrFn = .{ .token = it.index },
+        });
+        // ignore this and try again;
+        return error.ParseError;
     }
 
     return parseUse(arena, it, tree) catch |err| switch (err) {
diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index 7ddf9cc9c8..d837769802 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -84,6 +84,21 @@ test "recovery: continue after invalid decl" {
     });
 }
 
+test "recovery: invalid extern/inline" {
+    try testError(
+        \\inline test "" { a && b; }
+    , &[_]Error{
+        .ExpectedFn,
+        .InvalidAnd,
+    });
+    try testError(
+        \\extern "" test "" { a && b; }
+    , &[_]Error{
+        .ExpectedVarDeclOrFn,
+        .InvalidAnd,
+    });
+}
+
 test "zig fmt: top-level fields" {
     try testCanonical(
         \\a: did_you_know,