motiejus/zig
1
Fork 0
Code Releases Activity

stage2: "Pop" error trace for break/return within catch

Browse Source 
This implement trace "popping" for correctly handled errors within
`catch { ... }` and `else { ... }` blocks.

When breaking from these blocks with any non-error, we pop the error
trace frames corresponding to the operand. When breaking with an error,
we preserve the frames so that error traces "chain" together as usual.

```zig
fn foo(cond1: bool, cond2: bool) !void {
    bar() catch {
    	if (cond1) {
	    // If baz() result is a non-error, pop the error trace frames from bar()
	    // If baz() result is an error, leave the bar() frames on the error trace
            return baz();
	} else if (cond2) {
	    // If we break/return an error, then leave the error frames from bar() on the error trace
	    return error.Foo;
	}
    };

    // An error returned from here does not include bar()'s error frames in the trace
    return error.Bar;
}
```

Notice that if foo() does not return an error it, it leaves no extra
frames on the error trace.

This is piece (1/3) of https://github.com/ziglang/zig/issues/1923#issuecomment-1218495574
This commit is contained in:
Cody Tapscott
2022-09-12 23:05:50 -07:00
parent 5316a00a18
commit eda3eb1561
3 changed files with 301 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

185
test/stack_traces.zig
View File

@@ -98,6 +98,191 @@ pub fn addCases(cases: *tests.StackTracesContext) void {
},
});
cases.addCase(.{
.name = "try return + handled catch/if-else",
.source =
\\fn foo() !void {
\\ return error.TheSkyIsFalling;
\\}
\\
\\pub fn main() !void {
\\ foo() catch {}; // should not affect error trace
\\ if (foo()) |_| {} else |_| {
\\ // should also not affect error trace
\\ }
\\ try foo();
\\}
,
.Debug = .{
.expect =
\\error: TheSkyIsFalling
\\source.zig:2:5: [address] in foo (test)
\\ return error.TheSkyIsFalling;
\\ ^
\\source.zig:10:5: [address] in main (test)
\\ try foo();
\\ ^
\\
,
},
.ReleaseSafe = .{
.exclude_os = .{
.windows, // TODO
.linux, // defeated by aggressive inlining
},
.expect =
\\error: TheSkyIsFalling
\\source.zig:2:5: [address] in [function]
\\ return error.TheSkyIsFalling;
\\ ^
\\source.zig:10:5: [address] in [function]
\\ try foo();
\\ ^
\\
,
},
.ReleaseFast = .{
.expect =
\\error: TheSkyIsFalling
\\
,
},
.ReleaseSmall = .{
.expect =
\\error: TheSkyIsFalling
\\
,
},
});
cases.addCase(.{
.name = "try return from within catch",
.source =
\\fn foo() !void {
\\ return error.TheSkyIsFalling;
\\}
\\
\\fn bar() !void {
\\ return error.AndMyCarIsOutOfGas;
\\}
\\
\\pub fn main() !void {
\\ foo() catch { // error trace should include foo()
\\ try bar();
\\ };
\\}
,
.Debug = .{
.expect =
\\error: AndMyCarIsOutOfGas
\\source.zig:2:5: [address] in foo (test)
\\ return error.TheSkyIsFalling;
\\ ^
\\source.zig:6:5: [address] in bar (test)
\\ return error.AndMyCarIsOutOfGas;
\\ ^
\\source.zig:11:9: [address] in main (test)
\\ try bar();
\\ ^
\\
,
},
.ReleaseSafe = .{
.exclude_os = .{
.windows, // TODO
},
.expect =
\\error: AndMyCarIsOutOfGas
\\source.zig:2:5: [address] in [function]
\\ return error.TheSkyIsFalling;
\\ ^
\\source.zig:6:5: [address] in [function]
\\ return error.AndMyCarIsOutOfGas;
\\ ^
\\source.zig:11:9: [address] in [function]
\\ try bar();
\\ ^
\\
,
},
.ReleaseFast = .{
.expect =
\\error: AndMyCarIsOutOfGas
\\
,
},
.ReleaseSmall = .{
.expect =
\\error: AndMyCarIsOutOfGas
\\
,
},
});
cases.addCase(.{
.name = "try return from within if-else",
.source =
\\fn foo() !void {
\\ return error.TheSkyIsFalling;
\\}
\\
\\fn bar() !void {
\\ return error.AndMyCarIsOutOfGas;
\\}
\\
\\pub fn main() !void {
\\ if (foo()) |_| {} else |_| { // error trace should include foo()
\\ try bar();
\\ }
\\}
,
.Debug = .{
.expect =
\\error: AndMyCarIsOutOfGas
\\source.zig:2:5: [address] in foo (test)
\\ return error.TheSkyIsFalling;
\\ ^
\\source.zig:6:5: [address] in bar (test)
\\ return error.AndMyCarIsOutOfGas;
\\ ^
\\source.zig:11:9: [address] in main (test)
\\ try bar();
\\ ^
\\
,
},
.ReleaseSafe = .{
.exclude_os = .{
.windows, // TODO
},
.expect =
\\error: AndMyCarIsOutOfGas
\\source.zig:2:5: [address] in [function]
\\ return error.TheSkyIsFalling;
\\ ^
\\source.zig:6:5: [address] in [function]
\\ return error.AndMyCarIsOutOfGas;
\\ ^
\\source.zig:11:9: [address] in [function]
\\ try bar();
\\ ^
\\
,
},
.ReleaseFast = .{
.expect =
\\error: AndMyCarIsOutOfGas
\\
,
},
.ReleaseSmall = .{
.expect =
\\error: AndMyCarIsOutOfGas
\\
,
},
});
cases.addCase(.{
.name = "try try return return",
.source =