Commit 09304aab77a7b6af5693600fa6b3a35322f7469d | zig

author	Andrew Kelley <andrew@ziglang.org> 2018-07-29 23:25:40-04:00
committer	Andrew Kelley <andrew@ziglang.org> 2018-07-29 23:25:40-04:00
log	09304aab77a7b6af5693600fa6b3a35322f7469d
tree	82528045894e188bd7c5a22a23eb6b5ed6aa8b7e
parent	0d79e0381601404b844b4912d15d20f4b529e837

fix cancel and await semantics

2 files changed, 50 insertions(+), 25 deletions(-)

src
- ir.cpp
std
- debug
  - index.zig

src/ir.cpp+38-23

 @@ -6663,7 +6663,9 @@ static IrInstruction *ir_gen_fn_proto(IrBuilder *irb, Scope *parent_scope, AstNo
             async_allocator_type_value, is_var_args);
 }
-static IrInstruction *ir_gen_cancel_target(IrBuilder *irb, Scope *scope, AstNode *node, IrInstruction *target_inst) {
+static IrInstruction *ir_gen_cancel_target(IrBuilder *irb, Scope *scope, AstNode *node,
+        IrInstruction *target_inst, bool cancel_non_suspended, bool cancel_awaited)
+{
     IrBasicBlock *done_block = ir_create_basic_block(irb, scope, "CancelDone");
     IrBasicBlock *not_canceled_block = ir_create_basic_block(irb, scope, "NotCanceled");
     IrBasicBlock *pre_return_block = ir_create_basic_block(irb, scope, "PreReturn");
 @@ -6691,7 +6693,7 @@ static IrInstruction *ir_gen_cancel_target(IrBuilder *irb, Scope *scope, AstNode
     // set the is_canceled bit
     IrInstruction *prev_atomic_value = ir_build_atomic_rmw(irb, scope, node,
             usize_type_val, atomic_state_ptr, nullptr, is_canceled_mask, nullptr,
-            AtomicRmwOp_and, AtomicOrderSeqCst);
+            AtomicRmwOp_or, AtomicOrderSeqCst);
     IrInstruction *is_canceled_value = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, is_canceled_mask, false);
     IrInstruction *is_canceled_bool = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, is_canceled_value, zero, false);
 @@ -6703,14 +6705,26 @@ static IrInstruction *ir_gen_cancel_target(IrBuilder *irb, Scope *scope, AstNode
     ir_build_cond_br(irb, scope, node, is_returned_bool, post_return_block, pre_return_block, is_comptime);
     ir_set_cursor_at_end_and_append_block(irb, post_return_block);
-    IrInstruction *is_awaited_value = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, await_mask, false);
+    if (cancel_awaited) {
-    IrInstruction *is_awaited_bool = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, is_awaited_value, zero, false);
+        ir_build_br(irb, scope, node, do_cancel_block, is_comptime);
-    ir_build_cond_br(irb, scope, node, is_awaited_bool, done_block, do_cancel_block, is_comptime);
+    } else {
+        IrInstruction *is_awaited_value = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, await_mask, false);
+        IrInstruction *is_awaited_bool = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, is_awaited_value, zero, false);
+        ir_build_cond_br(irb, scope, node, is_awaited_bool, done_block, do_cancel_block, is_comptime);
+    }
     ir_set_cursor_at_end_and_append_block(irb, pre_return_block);
-    IrInstruction *is_suspended_value = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, is_suspended_mask, false);
+    if (cancel_awaited) {
-    IrInstruction *is_suspended_bool = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, is_suspended_value, zero, false);
+        if (cancel_non_suspended) {
-    ir_build_cond_br(irb, scope, node, is_suspended_bool, do_cancel_block, done_block, is_comptime);
+            ir_build_br(irb, scope, node, do_cancel_block, is_comptime);
+        } else {
+            IrInstruction *is_suspended_value = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, is_suspended_mask, false);
+            IrInstruction *is_suspended_bool = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, is_suspended_value, zero, false);
+            ir_build_cond_br(irb, scope, node, is_suspended_bool, do_cancel_block, done_block, is_comptime);
+        }
+    } else {
+        ir_build_br(irb, scope, node, done_block, is_comptime);
+    }
     ir_set_cursor_at_end_and_append_block(irb, do_cancel_block);
     ir_build_cancel(irb, scope, node, target_inst);
 @@ -6727,7 +6741,7 @@ static IrInstruction *ir_gen_cancel(IrBuilder *irb, Scope *scope, AstNode *node)
     if (target_inst == irb->codegen->invalid_instruction)
         return irb->codegen->invalid_instruction;
-    return ir_gen_cancel_target(irb, scope, node, target_inst);
+    return ir_gen_cancel_target(irb, scope, node, target_inst, false, true);
 }
 static IrInstruction *ir_gen_resume(IrBuilder *irb, Scope *scope, AstNode *node) {
 @@ -6872,15 +6886,19 @@ static IrInstruction *ir_gen_await_expr(IrBuilder *irb, Scope *scope, AstNode *n
     ir_build_unreachable(irb, scope, node);
     ir_set_cursor_at_end_and_append_block(irb, not_awaited_block);
+    IrInstruction *await_handle_addr = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, ptr_mask, false);
+    IrInstruction *is_non_null = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, await_handle_addr, zero, false);
     IrInstruction *is_canceled_value = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, is_canceled_mask, false);
     IrInstruction *is_canceled_bool = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, is_canceled_value, zero, false);
-    ir_build_cond_br(irb, scope, node, is_canceled_bool, cleanup_block, not_canceled_block, const_bool_false);
+    ir_build_cond_br(irb, scope, node, is_canceled_bool, cancel_target_block, not_canceled_block, const_bool_false);
     ir_set_cursor_at_end_and_append_block(irb, not_canceled_block);
-    IrInstruction *await_handle_addr = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, prev_atomic_value, ptr_mask, false);
-    IrInstruction *is_non_null = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, await_handle_addr, zero, false);
     ir_build_cond_br(irb, scope, node, is_non_null, no_suspend_block, yes_suspend_block, const_bool_false);
+    ir_set_cursor_at_end_and_append_block(irb, cancel_target_block);
+    ir_build_cancel(irb, scope, node, target_inst);
+    ir_mark_gen(ir_build_br(irb, scope, node, cleanup_block, const_bool_false));
     ir_set_cursor_at_end_and_append_block(irb, no_suspend_block);
     if (irb->codegen->have_err_ret_tracing) {
         Buf *err_ret_trace_field_name = buf_create_from_str(ERR_RET_TRACE_FIELD_NAME);
 @@ -6897,6 +6915,7 @@ static IrInstruction *ir_gen_await_expr(IrBuilder *irb, Scope *scope, AstNode *n
     ir_build_cancel(irb, scope, node, target_inst);
     ir_build_br(irb, scope, node, merge_block, const_bool_false);
     ir_set_cursor_at_end_and_append_block(irb, yes_suspend_block);
     IrInstruction *suspend_code = ir_build_coro_suspend(irb, scope, node, save_token, const_bool_false);
 @@ -6904,32 +6923,28 @@ static IrInstruction *ir_gen_await_expr(IrBuilder *irb, Scope *scope, AstNode *n
     cases[0].value = ir_build_const_u8(irb, scope, node, 0);
     cases[0].block = resume_block;
     cases[1].value = ir_build_const_u8(irb, scope, node, 1);
-    cases[1].block = cancel_target_block;
+    cases[1].block = cleanup_block;
     ir_build_switch_br(irb, scope, node, suspend_code, irb->exec->coro_suspend_block,
             2, cases, const_bool_false, nullptr);
-    ir_set_cursor_at_end_and_append_block(irb, cancel_target_block);
-    IrInstruction *await_handle = ir_build_int_to_ptr(irb, scope, node, promise_type_val, await_handle_addr);
-    ir_gen_cancel_target(irb, scope, node, await_handle);
-    ir_mark_gen(ir_build_br(irb, scope, node, cleanup_block, const_bool_false));
     ir_set_cursor_at_end_and_append_block(irb, cleanup_block);
     IrInstruction *my_mask_bits = ir_build_bin_op(irb, scope, node, IrBinOpBinOr, ptr_mask, is_canceled_mask, false);
     IrInstruction *my_prev_atomic_value = ir_build_atomic_rmw(irb, scope, node,
             usize_type_val, irb->exec->atomic_state_field_ptr, nullptr, my_mask_bits, nullptr,
             AtomicRmwOp_or, AtomicOrderSeqCst);
     IrInstruction *my_await_handle_addr = ir_build_bin_op(irb, scope, node, IrBinOpBinAnd, my_prev_atomic_value, ptr_mask, false);
-    IrInstruction *have_my_await_handle = ir_build_bin_op(irb, scope, node, IrBinOpCmpNotEq, my_await_handle_addr, zero, false);
+    IrInstruction *dont_have_my_await_handle = ir_build_bin_op(irb, scope, node, IrBinOpCmpEq, my_await_handle_addr, zero, false);
-    ir_build_cond_br(irb, scope, node, have_my_await_handle, do_cancel_block, do_defers_block, const_bool_false);
+    IrInstruction *dont_destroy_ourselves = ir_build_bin_op(irb, scope, node, IrBinOpBoolAnd, dont_have_my_await_handle, is_canceled_bool, false);
+    ir_build_cond_br(irb, scope, node, dont_have_my_await_handle, do_defers_block, do_cancel_block, const_bool_false);
     ir_set_cursor_at_end_and_append_block(irb, do_cancel_block);
     IrInstruction *my_await_handle = ir_build_int_to_ptr(irb, scope, node, promise_type_val, my_await_handle_addr);
-    ir_gen_cancel_target(irb, scope, node, my_await_handle);
+    ir_gen_cancel_target(irb, scope, node, my_await_handle, true, false);
     ir_mark_gen(ir_build_br(irb, scope, node, do_defers_block, const_bool_false));
     ir_set_cursor_at_end_and_append_block(irb, do_defers_block);
     ir_gen_defers_for_block(irb, scope, outer_scope, true);
-    ir_mark_gen(ir_build_br(irb, scope, node, irb->exec->coro_final_cleanup_block, const_bool_false));
+    ir_mark_gen(ir_build_cond_br(irb, scope, node, dont_destroy_ourselves, irb->exec->coro_early_final, irb->exec->coro_final_cleanup_block, const_bool_false));
     ir_set_cursor_at_end_and_append_block(irb, resume_block);
     ir_build_br(irb, scope, node, merge_block, const_bool_false);
 @@ -7004,7 +7019,7 @@ static IrInstruction *ir_gen_suspend(IrBuilder *irb, Scope *parent_scope, AstNod
     ir_set_cursor_at_end_and_append_block(irb, cancel_awaiter_block);
     IrInstruction *await_handle = ir_build_int_to_ptr(irb, parent_scope, node, promise_type_val, await_handle_addr);
-    ir_gen_cancel_target(irb, parent_scope, node, await_handle);
+    ir_gen_cancel_target(irb, parent_scope, node, await_handle, true, false);
     ir_build_br(irb, parent_scope, node, cleanup_block, const_bool_false);
     ir_set_cursor_at_end_and_append_block(irb, not_canceled_block);

std/debug/index.zig+12-2

 @@ -27,7 +27,7 @@ pub fn warn(comptime fmt: []const u8, args: ...) void {
     const stderr = getStderrStream() catch return;
     stderr.print(fmt, args) catch return;
 }
-fn getStderrStream() !*io.OutStream(io.FileOutStream.Error) {
+pub fn getStderrStream() !*io.OutStream(io.FileOutStream.Error) {
     if (stderr_stream) |st| {
         return st;
     } else {
 @@ -172,6 +172,16 @@ pub fn writeStackTrace(stack_trace: *const builtin.StackTrace, out_stream: var,
     }
 }
+pub inline fn getReturnAddress(frame_count: usize) usize {
+    var fp = @ptrToInt(@frameAddress());
+    var i: usize = 0;
+    while (fp != 0 and i < frame_count) {
+        fp = @intToPtr(*const usize, fp).*;
+        i += 1;
+    }
+    return @intToPtr(*const usize, fp + @sizeOf(usize)).*;
+}
 pub fn writeCurrentStackTrace(out_stream: var, allocator: *mem.Allocator, debug_info: *ElfStackTrace, tty_color: bool, start_addr: ?usize) !void {
     const AddressState = union(enum) {
         NotLookingForStartAddress,
 @@ -205,7 +215,7 @@ pub fn writeCurrentStackTrace(out_stream: var, allocator: *mem.Allocator, debug_
     }
 }
-fn printSourceAtAddress(debug_info: *ElfStackTrace, out_stream: var, address: usize, tty_color: bool) !void {
+pub fn printSourceAtAddress(debug_info: *ElfStackTrace, out_stream: var, address: usize, tty_color: bool) !void {
     switch (builtin.os) {
         builtin.Os.windows => return error.UnsupportedDebugInfo,
         builtin.Os.macosx => {