commit 282cb5ee5d75b4de2f215479b0c5531750908608 (tree)
parent 8f2af35eaaf94493b4e459e14a1eda7ef00b7f64
Author: Andrew Kelley <andrew@ziglang.org>
Date: Thu, 27 Jul 2023 11:07:10 -0700
Merge pull request #16559 from kcbanner/improve_compiler_rt_stack_trace
Unwinding follow up: Don't strip compiler_rt symbols, enable unwind tables on supported platforms
Diffstat:
9 files changed, 81 insertions(+), 24 deletions(-)
diff --git a/lib/std/Build/Step/CheckObject.zig b/lib/std/Build/Step/CheckObject.zig
@@ -478,8 +478,7 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
},
.not_present => {
while (it.next()) |line| {
- if (act.notPresent(b, step, line)) break;
- } else {
+ if (act.notPresent(b, step, line)) continue;
return step.fail(
\\
\\========= expected not to find: ===================
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
@@ -242,8 +242,7 @@ pub fn dumpStackTraceFromBase(context: *const ThreadContext) void {
printSourceAtAddress(debug_info, stderr, it.unwind_state.?.dwarf_context.pc, tty_config) catch return;
while (it.next()) |return_address| {
- if (it.getLastError()) |unwind_error|
- printUnwindError(debug_info, stderr, unwind_error.address, unwind_error.err, tty_config) catch {};
+ printLastUnwindError(&it, debug_info, stderr, tty_config);
// On arm64 macOS, the address of the last frame is 0x0 rather than 0x1 as on x86_64 macOS,
// therefore, we do a check for `return_address == 0` before subtracting 1 from it to avoid
@@ -252,7 +251,7 @@ pub fn dumpStackTraceFromBase(context: *const ThreadContext) void {
// same behaviour for x86-windows-msvc
const address = if (return_address == 0) return_address else return_address - 1;
printSourceAtAddress(debug_info, stderr, address, tty_config) catch return;
- }
+ } else printLastUnwindError(&it, debug_info, stderr, tty_config);
}
}
@@ -731,8 +730,7 @@ pub fn writeCurrentStackTrace(
defer it.deinit();
while (it.next()) |return_address| {
- if (it.getLastError()) |unwind_error|
- try printUnwindError(debug_info, out_stream, unwind_error.address, unwind_error.err, tty_config);
+ printLastUnwindError(&it, debug_info, out_stream, tty_config);
// On arm64 macOS, the address of the last frame is 0x0 rather than 0x1 as on x86_64 macOS,
// therefore, we do a check for `return_address == 0` before subtracting 1 from it to avoid
@@ -741,7 +739,7 @@ pub fn writeCurrentStackTrace(
// same behaviour for x86-windows-msvc
const address = if (return_address == 0) return_address else return_address - 1;
try printSourceAtAddress(debug_info, out_stream, address, tty_config);
- }
+ } else printLastUnwindError(&it, debug_info, out_stream, tty_config);
}
pub noinline fn walkStackWindows(addresses: []usize, existing_context: ?*const windows.CONTEXT) usize {
@@ -879,10 +877,21 @@ fn printUnknownSource(debug_info: *DebugInfo, out_stream: anytype, address: usiz
);
}
-pub fn printUnwindError(debug_info: *DebugInfo, out_stream: anytype, address: usize, err: UnwindError, tty_config: io.tty.Config) !void {
+fn printLastUnwindError(it: *StackIterator, debug_info: *DebugInfo, out_stream: anytype, tty_config: io.tty.Config) void {
+ if (!have_ucontext) return;
+ if (it.getLastError()) |unwind_error| {
+ printUnwindError(debug_info, out_stream, unwind_error.address, unwind_error.err, tty_config) catch {};
+ }
+}
+
+fn printUnwindError(debug_info: *DebugInfo, out_stream: anytype, address: usize, err: UnwindError, tty_config: io.tty.Config) !void {
const module_name = debug_info.getModuleNameForAddress(address) orelse "???";
try tty_config.setColor(out_stream, .dim);
- try out_stream.print("Unwind information for `{s}:0x{x}` was not available ({}), trace may be incomplete\n\n", .{ module_name, address, err });
+ if (err == error.MissingDebugInfo) {
+ try out_stream.print("Unwind information for `{s}:0x{x}` was not available, trace may be incomplete\n\n", .{ module_name, address });
+ } else {
+ try out_stream.print("Unwind error at address `{s}:0x{x}` ({}), trace may be incomplete\n\n", .{ module_name, address, err });
+ }
try tty_config.setColor(out_stream, .reset);
}
diff --git a/lib/std/dwarf.zig b/lib/std/dwarf.zig
@@ -1656,7 +1656,7 @@ pub const DwarfInfo = struct {
/// `explicit_fde_offset` is for cases where the FDE offset is known, such as when __unwind_info
/// defers unwinding to DWARF. This is an offset into the `.eh_frame` section.
pub fn unwindFrame(di: *const DwarfInfo, context: *UnwindContext, explicit_fde_offset: ?usize) !usize {
- if (!comptime abi.isSupportedArch(builtin.target.cpu.arch)) return error.UnsupportedCpuArchitecture;
+ if (!comptime abi.supportsUnwinding(builtin.target)) return error.UnsupportedCpuArchitecture;
if (context.pc == 0) return 0;
// Find the FDE and CIE
diff --git a/lib/std/dwarf/abi.zig b/lib/std/dwarf/abi.zig
@@ -3,13 +3,24 @@ const std = @import("../std.zig");
const os = std.os;
const mem = std.mem;
-pub fn isSupportedArch(arch: std.Target.Cpu.Arch) bool {
- return switch (arch) {
- .x86,
- .x86_64,
- .arm,
- .aarch64,
- => true,
+pub fn supportsUnwinding(target: std.Target) bool {
+ return switch (target.cpu.arch) {
+ .x86 => switch (target.os.tag) {
+ .linux, .netbsd, .solaris => true,
+ else => false,
+ },
+ .x86_64 => switch (target.os.tag) {
+ .linux, .netbsd, .freebsd, .openbsd, .macos, .solaris => true,
+ else => false,
+ },
+ .arm => switch (target.os.tag) {
+ .linux => true,
+ else => false,
+ },
+ .aarch64 => switch (target.os.tag) {
+ .linux, .netbsd, .freebsd, .macos => true,
+ else => false,
+ },
else => false,
};
}
diff --git a/src/Compilation.zig b/src/Compilation.zig
@@ -5491,6 +5491,7 @@ fn buildOutputFromZig(
.omit_frame_pointer = comp.bin_file.options.omit_frame_pointer,
.want_valgrind = false,
.want_tsan = false,
+ .want_unwind_tables = comp.bin_file.options.eh_frame_hdr,
.want_pic = comp.bin_file.options.pic,
.want_pie = comp.bin_file.options.pie,
.emit_h = null,
@@ -5639,9 +5640,5 @@ pub fn compilerRtOptMode(comp: Compilation) std.builtin.Mode {
/// This decides whether to strip debug info for all zig-provided libraries, including
/// compiler-rt, libcxx, libc, libunwind, etc.
pub fn compilerRtStrip(comp: Compilation) bool {
- if (comp.debug_compiler_runtime_libs) {
- return comp.bin_file.options.strip;
- } else {
- return true;
- }
+ return comp.bin_file.options.strip;
}
diff --git a/src/target.zig b/src/target.zig
@@ -510,7 +510,7 @@ pub fn clangAssemblerSupportsMcpuArg(target: std.Target) bool {
}
pub fn needUnwindTables(target: std.Target) bool {
- return target.os.tag == .windows or target.isDarwin();
+ return target.os.tag == .windows or target.isDarwin() or std.dwarf.abi.supportsUnwinding(target);
}
pub fn defaultAddressSpace(
diff --git a/test/standalone.zig b/test/standalone.zig
@@ -241,6 +241,10 @@ pub const build_cases = [_]BuildCase{
.build_root = "test/standalone/coff_dwarf",
.import = @import("standalone/coff_dwarf/build.zig"),
},
+ .{
+ .build_root = "test/standalone/compiler_rt_panic",
+ .import = @import("standalone/compiler_rt_panic/build.zig"),
+ },
};
const std = @import("std");
diff --git a/test/standalone/compiler_rt_panic/build.zig b/test/standalone/compiler_rt_panic/build.zig
@@ -0,0 +1,26 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+ const test_step = b.step("test", "Test it");
+ b.default_step = test_step;
+
+ const target = b.standardTargetOptions(.{});
+ const optimize = b.standardOptimizeOption(.{});
+
+ if (target.getObjectFormat() != .elf) return;
+
+ const exe = b.addExecutable(.{
+ .name = "main",
+ .optimize = optimize,
+ .target = target,
+ });
+ exe.addCSourceFile("main.c", &.{});
+ exe.link_gc_sections = false;
+ exe.bundle_compiler_rt = true;
+
+ // Verify compiler_rt hasn't pulled in any debug handlers
+ const check_exe = exe.checkObject();
+ check_exe.checkInSymtab();
+ check_exe.checkNotPresent("debug.readElfDebugInfo");
+ test_step.dependOn(&check_exe.step);
+}
diff --git a/test/standalone/compiler_rt_panic/main.c b/test/standalone/compiler_rt_panic/main.c
@@ -0,0 +1,11 @@
+#include <stddef.h>
+
+void* __memset(void* dest, char c, size_t n, size_t dest_n);
+
+char foo[128];
+
+int main() {
+ __memset(&foo[0], 0xff, 128, 128);
+ return foo[64];
+}
+
