Merge pull request #12889 from ziglang/unwrap-error-switch

safety: show error return trace when unwrapping error in switch

5 files changed, 12 insertions, 11 deletions

diff --git a/lib/c.zig b/lib/c.zig
index c08454a22c..4a6ca18782 100644
--- a/lib/c.zig
+++ b/lib/c.zig
@@ -58,7 +58,7 @@ comptime {
 
 // Avoid dragging in the runtime safety mechanisms into this .o file,
 // unless we're trying to test this file.
-pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace) noreturn {
+pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace, _: ?usize) noreturn {
     @setCold(true);
     _ = error_return_trace;
     if (builtin.is_test) {
diff --git a/lib/compiler_rt/common.zig b/lib/compiler_rt/common.zig
index 0147bd423b..a34b88429f 100644
--- a/lib/compiler_rt/common.zig
+++ b/lib/compiler_rt/common.zig
@@ -60,7 +60,7 @@ pub const want_sparc_abi = builtin.cpu.arch.isSPARC();
 
 // Avoid dragging in the runtime safety mechanisms into this .o file,
 // unless we're trying to test compiler-rt.
-pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace) noreturn {
+pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace, _: ?usize) noreturn {
     _ = error_return_trace;
     if (builtin.is_test) {
         @setCold(true);
diff --git a/lib/ssp.zig b/lib/ssp.zig
index b205a09e0a..f11698750d 100644
--- a/lib/ssp.zig
+++ b/lib/ssp.zig
@@ -20,7 +20,7 @@ extern fn memcpy(noalias dest: ?[*]u8, noalias src: ?[*]const u8, n: usize) call
 extern fn memmove(dest: ?[*]u8, src: ?[*]const u8, n: usize) callconv(.C) ?[*]u8;
 
 // Avoid dragging in the runtime safety mechanisms into this .o file.
-pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace) noreturn {
+pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace, _: ?usize) noreturn {
     _ = msg;
     _ = error_return_trace;
     @setCold(true);
diff --git a/lib/std/builtin.zig b/lib/std/builtin.zig
index d65e12988d..aff47ac6ba 100644
--- a/lib/std/builtin.zig
+++ b/lib/std/builtin.zig
@@ -748,7 +748,7 @@ const testFnProto = switch (builtin.zig_backend) {
 
 /// This function type is used by the Zig language code generation and
 /// therefore must be kept in sync with the compiler implementation.
-pub const PanicFn = fn ([]const u8, ?*StackTrace) noreturn;
+pub const PanicFn = fn ([]const u8, ?*StackTrace, ?usize) noreturn;
 
 /// This function is used by the Zig language code generation and
 /// therefore must be kept in sync with the compiler implementation.
@@ -761,7 +761,7 @@ else
 
 /// This function is used by the Zig language code generation and
 /// therefore must be kept in sync with the compiler implementation.
-pub fn default_panic(msg: []const u8, error_return_trace: ?*StackTrace) noreturn {
+pub fn default_panic(msg: []const u8, error_return_trace: ?*StackTrace, ret_addr: ?usize) noreturn {
     @setCold(true);
 
     // Until self-hosted catches up with stage1 language features, we have a simpler
@@ -839,7 +839,7 @@ pub fn default_panic(msg: []const u8, error_return_trace: ?*StackTrace) noreturn
             std.os.abort();
         },
         else => {
-            const first_trace_addr = @returnAddress();
+            const first_trace_addr = ret_addr orelse @returnAddress();
             std.debug.panicImpl(error_return_trace, first_trace_addr, msg);
         },
     }
@@ -853,17 +853,17 @@ pub fn checkNonScalarSentinel(expected: anytype, actual: @TypeOf(expected)) void
 
 pub fn panicSentinelMismatch(expected: anytype, actual: @TypeOf(expected)) noreturn {
     @setCold(true);
-    std.debug.panic("sentinel mismatch: expected {any}, found {any}", .{ expected, actual });
+    std.debug.panicExtra(null, @returnAddress(), "sentinel mismatch: expected {any}, found {any}", .{ expected, actual });
 }
 
 pub fn panicUnwrapError(st: ?*StackTrace, err: anyerror) noreturn {
     @setCold(true);
-    std.debug.panicExtra(st, "attempt to unwrap error: {s}", .{@errorName(err)});
+    std.debug.panicExtra(st, @returnAddress(), "attempt to unwrap error: {s}", .{@errorName(err)});
 }
 
 pub fn panicOutOfBounds(index: usize, len: usize) noreturn {
     @setCold(true);
-    std.debug.panic("index out of bounds: index {d}, len {d}", .{ index, len });
+    std.debug.panicExtra(null, @returnAddress(), "index out of bounds: index {d}, len {d}", .{ index, len });
 }
 
 pub noinline fn returnError(st: *StackTrace) void {
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index a7f0b202cb..cfe646647b 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -284,13 +284,14 @@ pub fn assert(ok: bool) void {
 pub fn panic(comptime format: []const u8, args: anytype) noreturn {
     @setCold(true);
 
-    panicExtra(null, format, args);
+    panicExtra(null, null, format, args);
 }
 
 /// `panicExtra` is useful when you want to print out an `@errorReturnTrace`
 /// and also print out some values.
 pub fn panicExtra(
     trace: ?*std.builtin.StackTrace,
+    ret_addr: ?usize,
     comptime format: []const u8,
     args: anytype,
 ) noreturn {
@@ -308,7 +309,7 @@ pub fn panicExtra(
             break :blk &buf;
         },
     };
-    std.builtin.panic(msg, trace);
+    std.builtin.panic(msg, trace, ret_addr);
 }
 
 /// Non-zero whenever the program triggered a panic.