2 * exception.c: exception support
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
13 #include <mono/arch/x86/x86-codegen.h>
14 #include <mono/metadata/appdomain.h>
15 #include <mono/metadata/tabledefs.h>
16 #include <mono/metadata/threads.h>
17 #include <mono/metadata/debug-helpers.h>
24 # define SC_EAX sc_eax
25 # define SC_EBX sc_ebx
26 # define SC_ECX sc_ecx
27 # define SC_EDX sc_edx
28 # define SC_EBP sc_ebp
29 # define SC_EIP sc_eip
30 # define SC_ESP sc_esp
31 # define SC_EDI sc_edi
32 # define SC_ESI sc_esi
46 * arch_get_restore_context:
48 * Returns a pointer to a method which restores a previously saved sigcontext.
51 arch_get_restore_context (void)
53 static guint8 *start = NULL;
59 /* restore_contect (struct sigcontext *ctx) */
60 /* we do not restore X86_EAX, X86_EDX */
62 start = code = g_malloc (1024);
65 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
67 /* get return address, stored in EDX */
68 x86_mov_reg_membase (code, X86_EDX, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_EIP), 4);
70 x86_mov_reg_membase (code, X86_EBX, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_EBX), 4);
72 x86_mov_reg_membase (code, X86_EDI, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_EDI), 4);
74 x86_mov_reg_membase (code, X86_ESI, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_ESI), 4);
76 x86_mov_reg_membase (code, X86_ESP, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_ESP), 4);
78 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_EBP), 4);
79 /* restore ECX. the exception object is passed here to the catch handler */
80 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_ECX), 4);
82 /* jump to the saved IP */
83 x86_jump_reg (code, X86_EDX);
89 * arch_get_call_finally:
91 * Returns a pointer to a method which calls a finally handler.
94 arch_get_call_finally (void)
96 static guint8 start [28];
97 static int inited = 0;
104 /* call_finally (struct sigcontext *ctx, unsigned long eip) */
107 x86_push_reg (code, X86_EBP);
108 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
109 x86_push_reg (code, X86_EBX);
110 x86_push_reg (code, X86_EDI);
111 x86_push_reg (code, X86_ESI);
114 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
116 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
118 x86_push_reg (code, X86_EBP);
120 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (struct sigcontext, SC_EBP), 4);
121 /* call the handler */
122 x86_call_reg (code, X86_ECX);
124 x86_pop_reg (code, X86_EBP);
125 /* restore saved regs */
126 x86_pop_reg (code, X86_ESI);
127 x86_pop_reg (code, X86_EDI);
128 x86_pop_reg (code, X86_EBX);
132 g_assert ((code - start) < 28);
138 * arch_handle_exception:
139 * @ctx: saved processor state
143 arch_handle_exception (struct sigcontext *ctx, gpointer obj)
145 MonoDomain *domain = mono_domain_get ();
147 gpointer ip = (gpointer)ctx->SC_EIP;
148 static void (*restore_context) (struct sigcontext *);
149 static void (*call_finally) (struct sigcontext *, unsigned long);
150 void (*cleanup) (MonoObject *exc);
151 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
152 gpointer end_of_stack;
154 g_assert (ctx != NULL);
155 g_assert (obj != NULL);
157 ji = mono_jit_info_table_find (domain, ip);
159 end_of_stack = jit_tls->end_of_stack;
160 g_assert (end_of_stack);
162 if (!restore_context)
163 restore_context = arch_get_restore_context ();
166 call_finally = arch_get_call_finally ();
168 cleanup = jit_tls->abort_func;
170 if (ji) { /* we are inside managed code */
171 MonoMethod *m = ji->method;
174 if (mono_object_isinst (obj, mono_defaults.exception_class)) {
175 char *strace = mono_string_to_utf8 (((MonoException*)obj)->stack_trace);
176 char *tmp, *tmpsig, *source_location, *tmpaddr;
177 gint32 address, iloffset;
179 if (!strcmp (strace, "TODO: implement stack traces")){
181 strace = g_strdup ("");
184 address = (char *)ip - (char *)ji->code_start;
186 source_location = mono_debug_source_location_from_address (m, address);
187 iloffset = mono_debug_il_offset_from_address (m, address);
190 tmpaddr = g_strdup_printf ("<0x%05x>", address);
192 tmpaddr = g_strdup_printf ("[0x%05x]", iloffset);
194 tmpsig = mono_signature_get_desc(m->signature, TRUE);
196 tmp = g_strdup_printf ("%sin %s (at %s) %s.%s:%s (%s)\n", strace, tmpaddr,
197 source_location, m->klass->name_space, m->klass->name,
200 tmp = g_strdup_printf ("%sin %s %s.%s:%s (%s)\n", strace, tmpaddr,
201 m->klass->name_space, m->klass->name, m->name, tmpsig);
202 g_free (source_location);
206 ((MonoException*)obj)->stack_trace = mono_string_new (domain, tmp);
210 if (ji->num_clauses) {
213 g_assert (ji->clauses);
215 for (i = 0; i < ji->num_clauses; i++) {
216 MonoJitExceptionInfo *ei = &ji->clauses [i];
218 if (ei->try_start <= ip && ip <= (ei->try_end)) {
220 if (ei->flags == 0 && mono_object_isinst (obj,
221 mono_class_get (m->klass->image, ei->token_or_filter))) {
223 ctx->SC_EIP = (unsigned long)ei->handler_start;
224 ctx->SC_ECX = (unsigned long)obj;
225 restore_context (ctx);
226 g_assert_not_reached ();
231 /* no handler found - we need to call all finally handlers */
232 for (i = 0; i < ji->num_clauses; i++) {
233 MonoJitExceptionInfo *ei = &ji->clauses [i];
235 if (ei->try_start <= ip && ip < (ei->try_end) &&
236 (ei->flags & MONO_EXCEPTION_CLAUSE_FINALLY)) {
237 call_finally (ctx, (unsigned long)ei->handler_start);
242 /* continue unwinding */
245 /* restore caller saved registers */
246 if (ji->used_regs & X86_ESI_MASK) {
247 ctx->SC_EBX = *((int *)ctx->SC_EBP + offset);
250 if (ji->used_regs & X86_EDI_MASK) {
251 ctx->SC_EDI = *((int *)ctx->SC_EBP + offset);
254 if (ji->used_regs & X86_EBX_MASK) {
255 ctx->SC_ESI = *((int *)ctx->SC_EBP + offset);
258 ctx->SC_ESP = ctx->SC_EBP;
259 ctx->SC_EIP = *((int *)ctx->SC_EBP + 1) - 5;
260 ctx->SC_EBP = *((int *)ctx->SC_EBP);
262 if (ctx->SC_EBP < (unsigned)end_of_stack)
263 arch_handle_exception (ctx, obj);
270 MonoLMF *lmf = jit_tls->lmf;
279 jit_tls->lmf = lmf->previous_lmf;
281 ctx->SC_ESI = lmf->esi;
282 ctx->SC_EDI = lmf->edi;
283 ctx->SC_EBX = lmf->ebx;
284 ctx->SC_EBP = lmf->ebp;
285 ctx->SC_EIP = lmf->eip;
286 ctx->SC_ESP = (unsigned long)&lmf->eip;
288 if (mono_object_isinst (obj, mono_defaults.exception_class)) {
289 char *strace = mono_string_to_utf8 (((MonoException*)obj)->stack_trace);
292 if (!strcmp (strace, "TODO: implement stack traces"))
293 strace = g_strdup ("");
295 tmp = g_strdup_printf ("%sin (unmanaged) %s.%s:%s ()\n", strace, m->klass->name_space,
296 m->klass->name, m->name);
300 ((MonoException*)obj)->stack_trace = mono_string_new (domain, tmp);
304 if (ctx->SC_EBP < (unsigned)end_of_stack)
305 arch_handle_exception (ctx, obj);
312 g_assert_not_reached ();
316 throw_exception (unsigned long eax, unsigned long ecx, unsigned long edx, unsigned long ebx,
317 unsigned long esi, unsigned long edi, unsigned long ebp, MonoObject *exc,
318 unsigned long eip, unsigned long esp)
320 struct sigcontext ctx;
322 /* adjust eip so that it point to the call instruction */
335 arch_handle_exception (&ctx, exc);
337 g_assert_not_reached ();
341 * arch_get_throw_exception:
343 * Returns a function pointer which can be used to raise
344 * exceptions. The returned function has the following
345 * signature: void (*func) (MonoException *exc);
346 * For example to raise an arithmetic exception you can use:
348 * x86_push_imm (code, mono_get_exception_arithmetic ());
349 * x86_call_code (code, arch_get_throw_exception ());
353 arch_get_throw_exception (void)
355 static guint8 start [24];
356 static int inited = 0;
365 x86_push_reg (code, X86_ESP);
366 x86_push_membase (code, X86_ESP, 4); /* IP */
367 x86_push_membase (code, X86_ESP, 12); /* exception */
368 x86_push_reg (code, X86_EBP);
369 x86_push_reg (code, X86_EDI);
370 x86_push_reg (code, X86_ESI);
371 x86_push_reg (code, X86_EBX);
372 x86_push_reg (code, X86_EDX);
373 x86_push_reg (code, X86_ECX);
374 x86_push_reg (code, X86_EAX);
375 x86_call_code (code, throw_exception);
376 /* we should never reach this breakpoint */
377 x86_breakpoint (code);
379 g_assert ((code - start) < 24);
384 * arch_get_throw_exception_by_name:
386 * Returns a function pointer which can be used to raise
387 * corlib exceptions. The returned function has the following
388 * signature: void (*func) (char *exc_name);
389 * For example to raise an arithmetic exception you can use:
391 * x86_push_imm (code, "ArithmeticException");
392 * x86_call_code (code, arch_get_throw_exception ());
396 arch_get_throw_exception_by_name ()
398 static guint8 start [32];
399 static int inited = 0;
408 /* fixme: we do not save EAX, EDX, ECD - unsure if we need that */
410 x86_push_membase (code, X86_ESP, 4); /* exception name */
411 x86_push_imm (code, "System");
412 x86_push_imm (code, mono_defaults.exception_class->image);
413 x86_call_code (code, mono_exception_from_name);
414 x86_alu_reg_imm (code, X86_ADD, X86_ESP, 12);
415 /* save the newly create object (overwrite exception name)*/
416 x86_mov_membase_reg (code, X86_ESP, 4, X86_EAX, 4);
417 x86_jump_code (code, arch_get_throw_exception ());
419 g_assert ((code - start) < 32);