Implement stack traces

git-svn-id: file:///svnroot/mailfromd/trunk@1363 7a8a7f39-df28-0410-adc6-e0d955640f24

7 files changed, 105 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index d7aa9de3..e11165f8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2007-04-18  Sergey Poznyakoff  <gray@gnu.org.ua>
 
+	* src/gram.y (apply_deferred_init): Fix error messages
+	* src/mailfromd.h, src/prog.c, src/main.c, src/bi_other.m4,
+	NEWS: Implement stack traces.
+	
 	* mflib/match_dnsbl.mf, mflib/heloarg_test.mf,
 	mflib/valid_domain.mf, mflib/match_rhsbl.mf, mflib/spf.mf,
 	mflib/match_cidr.mf, doc/mailfromd.texi: Use <> in #include
diff --git a/NEWS b/NEWS
index 3d9c3420..6e68fc69 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,4 @@
-Mailfromd NEWS -- history of user-visible changes. 2007-04-16
+Mailfromd NEWS -- history of user-visible changes. 2007-04-18
 Copyright (C) 2005, 2006, 2007 Sergey Poznyakoff
 See the end of file for copying conditions.
 
@@ -82,6 +82,31 @@ to the logs, notifying of the new stack size, e.g.:
 You can use these messages to adjust your stack size configuration
 settings. 
     
+* Runtime stack traces
+
+New command line option --stack-trace enables dumping stack traces
+on runtime errors.  This might help localize the source of the error.
+The trace looks like:
+
+mailfromd: RUNTIME ERROR near ../mflib/match_cidr.mf:30: invalid CIDR (boo%)
+mailfromd: Stack trace:
+mailfromd: 0077: test.mf:7: match_cidr
+mailfromd: 0096: test.mf:13: bar
+mailfromd: 0110: test.mf:18: foo
+mailfromd: Stack trace finishes
+mailfromd: Execution of the configuration program was not finished
+
+Each trace line describes one stack frame, the lines appear in the
+order of most recently called to least recently called.  Each frame
+consists of:
+
+1. Value of program counter at the time of its execution
+2. Source code location, if available
+3. Name of the function called
+
+The same output can be obtained by calling function stack_trace()
+in your filter program.
+
 * connect handler
 
 Connect handler is implemented.
diff --git a/src/bi_other.m4 b/src/bi_other.m4
index 5c7ed7d3..94e3e029 100644
--- a/src/bi_other.m4
+++ b/src/bi_other.m4
@@ -112,4 +112,10 @@ MF_DEFUN(cancel_program_trace, VOID, STRING name)
 }
 END	
 
+MF_DEFUN(stack_trace, VOID)
+{
+	runtime_stack_trace(env);
+}
+END
+
 MF_INIT
diff --git a/src/gram.y b/src/gram.y
index 24fab3a2..4a308411 100644
--- a/src/gram.y
+++ b/src/gram.y
@@ -3470,13 +3470,13 @@ apply_deferred_init()
 	for (p = deferred_decl; p; p = p->next) {
 		struct variable *var = variable_lookup(p->name->text);
 		if (!var) {
-			mu_error("<command line>: warning: no such variable %s",
-				 p->name);
+			mu_error("<command line>: warning: no such variable: %s",
+				 p->name->text);
 			continue;
 		}
 		if (initialize_variable(var, &p->value, get_locus()))
 			mu_error("error initialising variable %s: incompatible types",
-				 p->name);
+				 p->name->text);
 	}
 }
 
diff --git a/src/mailfromd.h b/src/mailfromd.h
index c09f834b..23574182 100644
--- a/src/mailfromd.h
+++ b/src/mailfromd.h
@@ -275,6 +275,7 @@ extern int script_dump_xref;
 extern size_t lock_retry_count_option;
 extern time_t lock_retry_timeout_option;
 extern char *mailfromd_state_dir;
+extern int stack_trace_option;
 
 
 /* Configuration file parser */
diff --git a/src/main.c b/src/main.c
index d9be5103..450129fb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -92,7 +92,7 @@ time_t lock_retry_timeout_option = 1;
 /* DBM-related options end */
 
 int source_info_option;          /* Debug messages include source locations */
-
+int stack_trace_option;          /* Print stack traces on runtime errors */
 char *file_option;               /* File name for DB management commands */
 struct db_format *format_option;
 
@@ -652,6 +652,12 @@ set_source_info(void *value)
 	source_info_option = (int) value;
 }
 
+void
+set_stack_trace(void *value)
+{
+	stack_trace_option = (int) value;
+}
+
 static void
 set_lock_retry_count(void *value)
 {
@@ -844,6 +850,7 @@ struct option_cache {
 	{ "ehlo", NULL, option_ehlo, set_ehlo },
 	{ "debug", NULL, option_debug, set_debug },
 	{ "source-info", NULL, option_boolean, set_source_info },
+	{ "stack-trace", NULL, option_boolean, set_stack_trace },
 	{ "expire-interval", NULL, option_time, set_expire },
 	{ "positive-expire-interval", NULL, option_time, set_positive_expire },
 	{ "negative-expire-interval", NULL, option_time, set_negative_expire },
@@ -939,6 +946,7 @@ enum mailfromd_option {
 	OPTION_PREDICT_NEXT,
 	OPTION_SHOW_DEFAULTS,
 	OPTION_SINGLE_PROCESS,
+	OPTION_STACK_TRACE,
 	OPTION_SOURCE_INFO,
 	OPTION_SYSLOG,
 	OPTION_TIME_FORMAT,
@@ -1085,6 +1093,8 @@ static struct argp_option options[] = {
 	  N_("Set the identifier used in syslog messages to STRING"), GRP+1 },
 	{ "source-info", OPTION_SOURCE_INFO, NULL, 0,
 	  N_("Debug messages include source information"), GRP+1 },
+	{ "stack-trace", OPTION_STACK_TRACE, NULL, 0,
+	  N_("Enable stack traces on runtime errors"), GRP+1 },
 #undef GRP
 
 	/*DEPRECATED OPTIONS*/
@@ -1347,6 +1357,10 @@ parse_opt (int key, char *arg, struct argp_state *state)
 		single_process_option = 1;
 		break;
 		
+	case OPTION_STACK_TRACE:
+		set_option("stack-trace", "yes", 1);
+		break;
+		
 	case OPTION_SOURCE_INFO:
 		set_option("source-info", "yes", 1);
 		break;
diff --git a/src/prog.c b/src/prog.c
index 720cef89..a29e1979 100644
--- a/src/prog.c
+++ b/src/prog.c
@@ -358,6 +358,54 @@ prog_trace(eval_environ_t env, const char *fmt, ...)
 	       buf);
 }	
 
+void instr_funcall(eval_environ_t env);
+void instr_locus(eval_environ_t env);
+
+void
+runtime_stack_trace(eval_environ_t env)
+{
+	size_t base;
+
+	mu_error("Stack trace:");
+	for (base = env->base; base < datasize + env->stack_size - 4;
+	     base = (size_t) env->dataseg[base + 1] + base + 1) {
+		int i;
+		prog_counter_t pc = (prog_counter_t)env->dataseg[base + 2] - 1;
+		char *name;
+		struct locus *ploc = NULL, loc;
+		
+		if (prog[pc-2] == instr_funcall) {
+			name = (char*)(env->dataseg + (size_t) prog[pc-1]);
+			pc -= 2;
+		} else {
+			name = "(in catch)";
+			pc -= 3;
+		}
+
+		for (i = 0; i < 10; i++) {
+			if (pc > i + 3
+			    && prog[pc - i - 3] == instr_locus) {
+				loc.file = (char*)(env->dataseg
+						   + (size_t) prog[pc - i - 2]);
+				loc.line = (size_t) prog[pc - i - 1];
+				ploc = &loc;
+				break;
+			}
+		}
+		
+		if (ploc)
+			mu_error("%04d: %s:%lu: %s",
+				 (unsigned long) pc,
+				 ploc->file, (unsigned long) ploc->line,
+				 name);
+		else
+			mu_error("%04d: %s",
+				 (unsigned long) pc,
+				 name);
+	}
+	mu_error("Stack trace finishes");
+}
+
 void
 runtime_warning(eval_environ_t env, const char *fmt, ...)
 {
@@ -386,6 +434,8 @@ runtime_error(eval_environ_t env, const char *fmt, ...)
 	vsnprintf(buf + n, sizeof buf - n, fmt, ap);
 	va_end(ap);
 	mu_error(buf);
+	if (stack_trace_option)
+		runtime_stack_trace(env);
 	env->status = SMFIS_TEMPFAIL; /* FIXME */
 	longjmp(env->x_jmp, 1);
 }