From fc4e65b479a2e5c73f3f5eaa7b578df6a6573b36 Mon Sep 17 00:00:00 2001
From: alex <alex@cloudware.io>
Date: Sat, 30 Jul 2022 16:45:32 +0200
Subject: [PATCH] set up a UB handler thanks to zig

activated in debug and safe release modes.
---
 build.zig        | 6 ++++++
 src/segfault.zig | 8 ++++++++
 x.c              | 5 +++++
 3 files changed, 19 insertions(+)
 create mode 100644 src/segfault.zig

diff --git a/build.zig b/build.zig
index 7446c7a..b7f0ac9 100644
--- a/build.zig
+++ b/build.zig
@@ -4,10 +4,16 @@ pub fn build(b: *std.build.Builder) void {
     const target = b.standardTargetOptions(.{});
     const mode = b.standardReleaseOptions();
 
+    const libsegfault = b.addStaticLibrary("segfault", "src/segfault.zig");
+    libsegfault.setTarget(target);
+    libsegfault.setBuildMode(mode);
+    libsegfault.force_pic = true;
+
     const exe = b.addExecutable("st", null);
     exe.setTarget(target);
     exe.setBuildMode(mode);
     exe.install();
+    exe.linkLibrary(libsegfault);
     exe.linkSystemLibrary("fontconfig");
     exe.linkSystemLibrary("freetype2");
     exe.linkSystemLibrary("Xft");
diff --git a/src/segfault.zig b/src/segfault.zig
new file mode 100644
index 0000000..de11c91
--- /dev/null
+++ b/src/segfault.zig
@@ -0,0 +1,8 @@
+const std = @import("std");
+
+/// installs a segfault handler on supported platforms in debug and safe modes.
+/// while a zig main does this automatically, a C main will want to call this explicitly.
+/// hence, the export for C call convention.
+export fn setupSegfaultHandler() void {
+    std.debug.maybeEnableSegfaultHandler();
+}
diff --git a/x.c b/x.c
index 23af62b..9c72acd 100644
--- a/x.c
+++ b/x.c
@@ -61,6 +61,8 @@ static void zoomabs(const Arg *);
 static void zoomreset(const Arg *);
 static void ttysend(const Arg *);
 
+extern void setupSegfaultHandler(void);
+
 /* config.h for applying patches and the configuration. */
 #include "config.h"
 
@@ -2103,6 +2105,9 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
+	// install zig's UB handler.
+	setupSegfaultHandler();
+
 	xw.l = xw.t = 0;
 	xw.isfixed = False;
 	xsetcursor(cursorshape);