OpenBSD support.

Special treatment here as backtrace support is optional,
cannot be found via pkg-config and similar neither.

src/Makefile

@@ -102,6 +102,12 @@ else
 ifeq ($(uname_S),OpenBSD)
 	# OpenBSD
 	FINAL_LIBS+= -lpthread
+	ifeq ($(USE_BACKTRACE),yes)
+	    FINAL_CFLAGS+= -DUSE_BACKTRACE -I/usr/local/include
+	    FINAL_LDFLAGS+= -L/usr/local/lib
+	    FINAL_LIBS+= -lexecinfo
+    	endif
+
 else
 ifeq ($(uname_S),FreeBSD)
 	# FreeBSD

src/config.h

@@ -63,7 +63,8 @@
 
 /* Test for backtrace() */
 #if defined(__APPLE__) || (defined(__linux__) && defined(__GLIBC__)) || \
-    defined(__FreeBSD__) || defined(__DragonFly__)
+    defined(__FreeBSD__) || (defined(__OpenBSD__) && defined(USE_BACKTRACE))\
+ || defined(__DragonFly__)
 #define HAVE_BACKTRACE 1
 #endif
 

src/debug.c

@@ -37,7 +37,11 @@
 
 #ifdef HAVE_BACKTRACE
 #include <execinfo.h>
+#ifndef __OpenBSD__
 #include <ucontext.h>
+#else
+typedef ucontext_t sigcontext_t;
+#endif
 #include <fcntl.h>
 #include "bio.h"
 #include <unistd.h>
@@ -736,6 +740,13 @@ static void *getMcontextEip(ucontext_t *uc) {
     #elif defined(__x86_64__)
     return (void*) uc->uc_mcontext.mc_rip;
     #endif
+#elif defined(__OpenBSD__)
+    /* OpenBSD */
+    #if defined(__i386__)
+    return (void*) uc->sc_eip;
+    #elif defined(__x86_64__)
+    return (void*) uc->sc_rip;
+    #endif
 #elif defined(__DragonFly__)
     return (void*) uc->uc_mcontext.mc_rip;
 #else
@@ -934,6 +945,61 @@ void logRegisters(ucontext_t *uc) {
     );
     logStackContent((void**)uc->uc_mcontext.mc_esp);
     #endif
+#elif defined(__OpenBSD__)
+    #if defined(__x86_64__)
+    serverLog(LL_WARNING,
+    "\n"
+    "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
+    "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
+    "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
+    "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
+    "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
+        (unsigned long) uc->sc_rax,
+        (unsigned long) uc->sc_rbx,
+        (unsigned long) uc->sc_rcx,
+        (unsigned long) uc->sc_rdx,
+        (unsigned long) uc->sc_rdi,
+        (unsigned long) uc->sc_rsi,
+        (unsigned long) uc->sc_rbp,
+        (unsigned long) uc->sc_rsp,
+        (unsigned long) uc->sc_r8,
+        (unsigned long) uc->sc_r9,
+        (unsigned long) uc->sc_r10,
+        (unsigned long) uc->sc_r11,
+        (unsigned long) uc->sc_r12,
+        (unsigned long) uc->sc_r13,
+        (unsigned long) uc->sc_r14,
+        (unsigned long) uc->sc_r15,
+        (unsigned long) uc->sc_rip,
+        (unsigned long) uc->sc_rflags,
+        (unsigned long) uc->sc_cs
+    );
+    logStackContent((void**)uc->sc_rsp);
+    #elif defined(__i386__)
+    serverLog(LL_WARNING,
+    "\n"
+    "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
+    "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
+    "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
+    "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
+        (unsigned long) uc->sc_eax,
+        (unsigned long) uc->sc_ebx,
+        (unsigned long) uc->sc_ebx,
+        (unsigned long) uc->sc_edx,
+        (unsigned long) uc->sc_edi,
+        (unsigned long) uc->sc_esi,
+        (unsigned long) uc->sc_ebp,
+        (unsigned long) uc->sc_esp,
+        (unsigned long) uc->sc_ss,
+        (unsigned long) uc->sc_eflags,
+        (unsigned long) uc->sc_eip,
+        (unsigned long) uc->sc_cs,
+        (unsigned long) uc->sc_es,
+        (unsigned long) uc->sc_fs,
+        (unsigned long) uc->sc_gs
+    );
+    logStackContent((void**)uc->sc_esp);
+    #endif
 #elif defined(__DragonFly__)
     serverLog(LL_WARNING,
     "\n"