From 02c5bda704d30e95e6af23804f9a552e9d8ca2d7 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Fri, 27 Jul 2018 17:27:03 -0400
Subject: [PATCH] remove ability to break from suspend blocks

closes #803
---
 doc/langref.html.in |  2 +-
 src/all_types.hpp   |  2 --
 src/analyze.cpp     |  1 -
 src/ir.cpp          | 17 ++---------------
 src/parser.cpp      | 25 ++-----------------------
 5 files changed, 5 insertions(+), 42 deletions(-)

diff --git a/doc/langref.html.in b/doc/langref.html.in
index 60ba09d391..d91fb6e8fb 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -7336,7 +7336,7 @@ Defer(body) = ("defer" | "deferror") body
 
 IfExpression(body) = "if" "(" Expression ")" body option("else" BlockExpression(body))
 
-SuspendExpression(body) = option(Symbol ":") "suspend" option(("|" Symbol "|" body))
+SuspendExpression(body) = "suspend" option(("|" Symbol "|" body))
 
 IfErrorExpression(body) = "if" "(" Expression ")" option("|" option("*") Symbol "|") body "else" "|" Symbol "|" BlockExpression(body)
 
diff --git a/src/all_types.hpp b/src/all_types.hpp
index 3ac7afe474..2f09e70301 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -898,7 +898,6 @@ struct AstNodeAwaitExpr {
 };
 
 struct AstNodeSuspend {
-    Buf *name;
     AstNode *block;
     AstNode *promise_symbol;
 };
@@ -1929,7 +1928,6 @@ struct ScopeLoop {
 struct ScopeSuspend {
     Scope base;
 
-    Buf *name;
     IrBasicBlock *resume_block;
     bool reported_err;
 };
diff --git a/src/analyze.cpp b/src/analyze.cpp
index 74d59f966a..03cfa5b67b 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -161,7 +161,6 @@ ScopeSuspend *create_suspend_scope(AstNode *node, Scope *parent) {
     assert(node->type == NodeTypeSuspend);
     ScopeSuspend *scope = allocate<ScopeSuspend>(1);
     init_scope(&scope->base, ScopeIdSuspend, node, parent);
-    scope->name = node->data.suspend.name;
     return scope;
 }
 
diff --git a/src/ir.cpp b/src/ir.cpp
index cd791fb189..799d7e3bc5 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -6186,15 +6186,6 @@ static IrInstruction *ir_gen_return_from_block(IrBuilder *irb, Scope *break_scop
     return ir_build_br(irb, break_scope, node, dest_block, is_comptime);
 }
 
-static IrInstruction *ir_gen_break_from_suspend(IrBuilder *irb, Scope *break_scope, AstNode *node, ScopeSuspend *suspend_scope) {
-    IrInstruction *is_comptime = ir_build_const_bool(irb, break_scope, node, false);
-
-    IrBasicBlock *dest_block = suspend_scope->resume_block;
-    ir_gen_defers_for_block(irb, break_scope, dest_block->scope, false);
-
-    return ir_build_br(irb, break_scope, node, dest_block, is_comptime);
-}
-
 static IrInstruction *ir_gen_break(IrBuilder *irb, Scope *break_scope, AstNode *node) {
     assert(node->type == NodeTypeBreak);
 
@@ -6235,12 +6226,8 @@ static IrInstruction *ir_gen_break(IrBuilder *irb, Scope *break_scope, AstNode *
                 return ir_gen_return_from_block(irb, break_scope, node, this_block_scope);
             }
         } else if (search_scope->id == ScopeIdSuspend) {
-            ScopeSuspend *this_suspend_scope = (ScopeSuspend *)search_scope;
-            if (node->data.break_expr.name != nullptr &&
-                (this_suspend_scope->name != nullptr && buf_eql_buf(node->data.break_expr.name, this_suspend_scope->name)))
-            {
-                return ir_gen_break_from_suspend(irb, break_scope, node, this_suspend_scope);
-            }
+            add_node_error(irb->codegen, node, buf_sprintf("cannot break out of suspend block"));
+            return irb->codegen->invalid_instruction;
         }
         search_scope = search_scope->parent;
     }
diff --git a/src/parser.cpp b/src/parser.cpp
index adb1633f5d..a93d8de830 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -648,30 +648,12 @@ static AstNode *ast_parse_asm_expr(ParseContext *pc, size_t *token_index, bool m
 }
 
 /*
-SuspendExpression(body) = option(Symbol ":") "suspend" option(("|" Symbol "|" body))
+SuspendExpression(body) = "suspend" option(("|" Symbol "|" body))
 */
 static AstNode *ast_parse_suspend_block(ParseContext *pc, size_t *token_index, bool mandatory) {
     size_t orig_token_index = *token_index;
 
-    Token *name_token = nullptr;
-    Token *token = &pc->tokens->at(*token_index);
-    if (token->id == TokenIdSymbol) {
-        *token_index += 1;
-        Token *colon_token = &pc->tokens->at(*token_index);
-        if (colon_token->id == TokenIdColon) {
-            *token_index += 1;
-            name_token = token;
-            token = &pc->tokens->at(*token_index);
-        } else if (mandatory) {
-            ast_expect_token(pc, colon_token, TokenIdColon);
-            zig_unreachable();
-        } else {
-            *token_index = orig_token_index;
-            return nullptr;
-        }
-    }
-
-    Token *suspend_token = token;
+    Token *suspend_token = &pc->tokens->at(*token_index);
     if (suspend_token->id == TokenIdKeywordSuspend) {
         *token_index += 1;
     } else if (mandatory) {
@@ -693,9 +675,6 @@ static AstNode *ast_parse_suspend_block(ParseContext *pc, size_t *token_index, b
     }
 
     AstNode *node = ast_create_node(pc, NodeTypeSuspend, suspend_token);
-    if (name_token != nullptr) {
-        node->data.suspend.name = token_buf(name_token);
-    }
     node->data.suspend.promise_symbol = ast_parse_symbol(pc, token_index);
     ast_eat_token(pc, token_index, TokenIdBinOr);
     node->data.suspend.block = ast_parse_block(pc, token_index, true);