jimzah/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2024-12-04 02:48:50 +00:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

runtime safety for noasync function calls

Browse Source 
See #3157
This commit is contained in:
Andrew Kelley 2019-09-06 12:50:51 -04:00
parent 0a3c6dbda9
commit 7d303ae861
No known key found for this signature in database
GPG Key ID: 7C5F548F728501A9
3 changed files with 37 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/all_types.hpp
View File

@ -1680,6 +1680,7 @@ enum PanicMsgId {
PanicMsgIdResumedAnAwaitingFn,
PanicMsgIdFrameTooSmall,
PanicMsgIdResumedFnPendingAwait,
PanicMsgIdBadNoAsyncCall,
PanicMsgIdCount,
};

21
src/codegen.cpp
View File

@ -923,6 +923,8 @@ static Buf *panic_msg_buf(PanicMsgId msg_id) {
return buf_create_from_str("frame too small");
case PanicMsgIdResumedFnPendingAwait:
return buf_create_from_str("resumed an async function which can only be awaited");
case PanicMsgIdBadNoAsyncCall:
return buf_create_from_str("async function called with noasync suspended");
}
zig_unreachable();
}
@ -4067,6 +4069,25 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
} else if (instruction->modifier == CallModifierNoAsync && !fn_is_async(g->cur_fn)) {
gen_resume(g, fn_val, frame_result_loc, ResumeIdCall);
if (ir_want_runtime_safety(g, &instruction->base)) {
LLVMValueRef awaiter_ptr = LLVMBuildStructGEP(g->builder, frame_result_loc,
frame_awaiter_index, "");
LLVMValueRef all_ones = LLVMConstAllOnes(usize_type_ref);
LLVMValueRef prev_val = gen_maybe_atomic_op(g, LLVMAtomicRMWBinOpXchg, awaiter_ptr,
all_ones, LLVMAtomicOrderingRelease);
LLVMValueRef ok_val = LLVMBuildICmp(g->builder, LLVMIntEQ, prev_val, all_ones, "");
LLVMBasicBlockRef bad_block = LLVMAppendBasicBlock(g->cur_fn_val, "NoAsyncPanic");
LLVMBasicBlockRef ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "NoAsyncOk");
LLVMBuildCondBr(g->builder, ok_val, ok_block, bad_block);
// The async function suspended, but this noasync call asserted it wouldn't.
LLVMPositionBuilderAtEnd(g->builder, bad_block);
gen_safety_crash(g, PanicMsgIdBadNoAsyncCall);
LLVMPositionBuilderAtEnd(g->builder, ok_block);
}
ZigType *result_type = instruction->base.value.type;
ZigType *ptr_result_type = get_pointer_to_type(g, result_type, true);
return gen_await_early_return(g, &instruction->base, frame_result_loc,

15
test/runtime_safety.zig
View File

@ -1,6 +1,21 @@
const tests = @import("tests.zig");
pub fn addCases(cases: *tests.CompareOutputContext) void {
cases.addRuntimeSafety("noasync function call, callee suspends",
\\pub fn panic(message: []const u8, stack_trace: ?*@import("builtin").StackTrace) noreturn {
\\ @import("std").os.exit(126);
\\}
\\pub fn main() void {
\\ _ = noasync add(101, 100);
\\}
\\fn add(a: i32, b: i32) i32 {
\\ if (a > 100) {
\\ suspend;
\\ }
\\ return a + b;
\\}
);
cases.addRuntimeSafety("awaiting twice",
\\pub fn panic(message: []const u8, stack_trace: ?*@import("builtin").StackTrace) noreturn {
\\ @import("std").os.exit(126);