$OpenBSD$

Index: runtime/druntime/src/core/sys/openbsd/execinfo.d
--- runtime/druntime/src/core/sys/openbsd/execinfo.d.orig
+++ runtime/druntime/src/core/sys/openbsd/execinfo.d
@@ -0,0 +1,133 @@
+/**
+ * NetBSD implementation of glibc's $(LINK2 http://www.gnu.org/software/libc/manual/html_node/Backtraces.html backtrace) facility.
+ *
+ * Copyright: Copyright Martin Nowak 2012.
+ * License:   $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
+ * Authors:   Martin Nowak
+ * Source:    $(DRUNTIMESRC core/sys/netbsd/_execinfo.d)
+ */
+module core.sys.openbsd.execinfo;
+
+version (OpenBSD):
+extern (C):
+nothrow:
+
+import core.sys.openbsd.dlfcn;
+
+// Use extern (D) so that these functions don't collide with libexecinfo.
+
+extern (D) int backtrace(void** buffer, int size)
+{
+    import core.thread : thread_stackBottom;
+
+    void** p, pend=cast(void**)thread_stackBottom();
+    version (D_InlineAsm_X86)
+        asm nothrow @trusted { mov p[EBP], EBP; }
+    else version (D_InlineAsm_X86_64)
+        asm nothrow @trusted { mov p[RBP], RBP; }
+    else
+        static assert(false, "Architecture not supported.");
+
+    int i;
+    for (; i < size && p < pend; ++i)
+    {
+        buffer[i] = *(p + 1);
+        auto pnext = cast(void**)*p;
+        if (pnext <= p) break;
+        p = pnext;
+    }
+    return i;
+}
+
+
+extern (D) char** backtrace_symbols(const(void*)* buffer, int size)
+{
+    static void* realloc(void* p, size_t len) nothrow
+    {
+        static import cstdlib=core.stdc.stdlib;
+        auto res = cstdlib.realloc(p, len);
+        if (res is null) cstdlib.free(p);
+        return res;
+    }
+
+    if (size <= 0) return null;
+
+    size_t pos = size * (char*).sizeof;
+    char** p = cast(char**)realloc(null, pos);
+    if (p is null) return null;
+
+    Dl_info info;
+    foreach (i, addr; buffer[0 .. size])
+    {
+        if (dladdr(addr, &info) == 0)
+            (cast(ubyte*)&info)[0 .. info.sizeof] = 0;
+        fixupDLInfo(addr, info);
+
+        immutable len = formatStackFrame(null, 0, addr, info);
+        assert(len > 0);
+
+        p = cast(char**)realloc(p, pos + len);
+        if (p is null) return null;
+
+        formatStackFrame(cast(char*)p + pos, len, addr, info) == len || assert(0);
+
+        p[i] = cast(char*)pos;
+        pos += len;
+    }
+    foreach (i; 0 .. size)
+    {
+        pos = cast(size_t)p[i];
+        p[i] = cast(char*)p + pos;
+    }
+    return p;
+}
+
+
+extern (D) void backtrace_symbols_fd(const(void*)* buffer, int size, int fd)
+{
+    import core.sys.posix.unistd : write;
+    import core.stdc.stdlib : alloca;
+
+    if (size <= 0) return;
+
+    Dl_info info;
+    foreach (i, addr; buffer[0 .. size])
+    {
+        if (dladdr(addr, &info) == 0)
+            (cast(ubyte*)&info)[0 .. info.sizeof] = 0;
+        fixupDLInfo(addr, info);
+
+        enum maxAlloca = 1024;
+        enum min = (size_t a, size_t b) => a <= b ? a : b;
+        immutable len = min(formatStackFrame(null, 0, addr, info), maxAlloca);
+        assert(len > 0);
+
+        auto p = cast(char*)alloca(len);
+        if (p is null) return;
+
+        formatStackFrame(p, len, addr, info) >= len || assert(0);
+        p[len - 1] = '\n';
+        write(fd, p, len);
+    }
+}
+
+
+private void fixupDLInfo(const(void)* addr, ref Dl_info info)
+{
+    if (info.dli_fname is null) info.dli_fname = "???";
+    if (info.dli_fbase is null) info.dli_fbase = null;
+    if (info.dli_sname is null) info.dli_sname = "???";
+    if (info.dli_saddr is null) info.dli_saddr = cast(void*)addr;
+}
+
+
+private size_t formatStackFrame(char* p, size_t plen, const(void)* addr, const ref Dl_info info)
+{
+    import core.stdc.stdio : snprintf;
+
+    immutable off = addr - info.dli_saddr;
+    immutable len = snprintf(p, plen, "%p <%s+%zd> at %s",
+                             addr, info.dli_sname, off, info.dli_fname);
+    assert(len > 0);
+    return cast(size_t)len + 1; // + '\0'
+}
