c/debug: StackTrace

c/debug/_demo/stacktrace/main.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/c/debug"
+)
+
+type T struct {
+	n int
+}
+
+func (t *T) Demo() {
+	println(t.n)
+	debug.StackTrace(0, func(fr *debug.Frame) bool {
+		var info debug.Info
+		debug.Addrinfo(unsafe.Pointer(fr.PC), &info)
+		println("[", fr.PC, "]", fr.Name, "+", fr.Offset, ", SP =", fr.SP)
+		return true
+	})
+}
+
+func main() {
+	t := &T{100}
+	t.Demo()
+}

c/debug/_wrap/debug.c

@@ -4,6 +4,7 @@
 #endif
 
 #include <dlfcn.h>
+#include <libunwind.h>
 
 void *llgo_address() {
     return __builtin_return_address(0);
@@ -12,3 +13,26 @@ void *llgo_address() {
 int llgo_addrinfo(void *addr, Dl_info *info) {
     return dladdr(addr, info);
 }
+
+void llgo_stacktrace(int skip, void *ctx, int (*fn)(void *ctx, void *pc, void *offset, void *sp, char *name)) {
+    unw_cursor_t cursor;
+    unw_context_t context;
+    unw_word_t offset, pc, sp;
+    char fname[256];
+    unw_getcontext(&context);
+    unw_init_local(&cursor, &context);
+    int depth = 0;
+    while (unw_step(&cursor) > 0) {
+        if (depth < skip) {
+            depth++;
+            continue;
+        }
+        if (unw_get_reg(&cursor, UNW_REG_IP, &pc) == 0) {
+            unw_get_proc_name(&cursor, fname, sizeof(fname), &offset);
+            unw_get_reg(&cursor, UNW_REG_SP, &sp);
+            if (fn(ctx, (void*)pc, (void*)offset, (void*)sp, fname) == 0) {
+                return;
+            }
+        }
+    }
+}

c/debug/debug.go

@@ -23,3 +23,23 @@ func Address() unsafe.Pointer
 
 //go:linkname Addrinfo C.llgo_addrinfo
 func Addrinfo(addr unsafe.Pointer, info *Info) c.Int
+
+//go:linkname stacktrace C.llgo_stacktrace
+func stacktrace(skip c.Int, ctx unsafe.Pointer, fn func(ctx, pc, offset, sp unsafe.Pointer, name *c.Char) c.Int)
+
+type Frame struct {
+	PC     uintptr
+	Offset uintptr
+	SP     unsafe.Pointer
+	Name   string
+}
+
+func StackTrace(skip int, fn func(fr *Frame) bool) {
+	stacktrace(c.Int(1+skip), unsafe.Pointer(&fn), func(ctx, pc, offset, sp unsafe.Pointer, name *c.Char) c.Int {
+		fn := *(*func(fr *Frame) bool)(ctx)
+		if !fn(&Frame{uintptr(pc), uintptr(offset), sp, c.GoString(name)}) {
+			return 0
+		}
+		return 1
+	})
+}