Add $ExpressionTimeLimit system variable.

src/dorem.c

@@ -1314,7 +1314,7 @@ int DoSatRemind(Trigger *trig, TimeTrig *tt, ParsePtr p)
             free_expr_tree(sat_node);
 	    return E_EXPIRED;
 	}
-        r = evaluate_expr_node(sat_node, NULL, &v, &nonconst);
+        r = evaluate_expression(sat_node, NULL, &v, &nonconst);
 	if (r) {
             free_expr_tree(sat_node);
             return r;

src/err.h

@@ -124,6 +124,7 @@
 #define E_EXPECTING_WEEKDAY 104
 #define E_REPEATED_ARG      105
 #define E_EXPR_DISABLED     106
+#define E_TIME_EXCEEDED     107
 
 #ifdef MK_GLOBALS
 #undef EXTERN
@@ -248,7 +249,8 @@ EXTERN char *ErrMsg[]
 /* E_DURATION_NO_AT */    "Cannot specify DURATION without specifying AT",
 /* E_EXPECTING_WEEKDAY */ "Expecting weekday name",
 /* E_REPEATED_ARG */      "Duplicate argument name",
-/* E_EXPR_DISABLED */     "Expression evaluation is disabled"
+/* E_EXPR_DISABLED */     "Expression evaluation is disabled",
+/* E_TIME_EXCEEDED */     "Time limit for expression evaluation exceeded",
 }
 #endif /* MK_GLOBALS */
 ;

src/expr.c

@@ -24,6 +24,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
+#include <unistd.h>
 
 /*
   The parser parses expressions into an internal tree
@@ -662,6 +663,21 @@ eval_userfunc(expr_node *node, Value *locals, Value *ans, int *nonconst)
     return r;
 }
 
+int
+evaluate_expression(expr_node *node, Value *locals, Value *ans, int *nonconst)
+{
+    int r;
+
+    /* Set up time limits */
+    if (ExpressionEvaluationTimeLimit > 0) {
+        ExpressionTimeLimitExceeded = 0;
+        alarm(ExpressionEvaluationTimeLimit);
+    }
+    r = evaluate_expr_node(node, locals, ans, nonconst);
+    alarm(0);
+    return r;
+}
+
 /***************************************************************/
 /*                                                             */
 /* evaluate_expr_node - the top-level expression evaluation    */
@@ -691,6 +707,10 @@ evaluate_expr_node(expr_node *node, Value *locals, Value *ans, int *nonconst)
         return E_EXPR_DISABLED;
     }
 
+    if (ExpressionTimeLimitExceeded) {
+        ExpressionTimeLimitExceeded = 0;
+        return E_TIME_EXCEEDED;
+    }
     if (!node) {
         return E_SWERR;
     }
@@ -2370,7 +2390,7 @@ int EvalExpr(char const **e, Value *v, ParsePtr p)
     }
 
     /* Evaluate */
-    r = evaluate_expr_node(n, NULL, v, &nonconst);
+    r = evaluate_expression(n, NULL, v, &nonconst);
 
     /* Throw away the parsed tree */
     free_expr_tree(n);

src/globals.h

@@ -23,6 +23,7 @@
 #define INIT(var, val) var
 #endif
 
+#include <signal.h>
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -74,6 +75,8 @@ EXTERN  INIT(   int     DefaultTDelta, 0);
 EXTERN  INIT(   int     DeltaOverride, 0);
 EXTERN  INIT(   int     RunDisabled, 0);
 EXTERN  INIT(   int     ExpressionEvaluationDisabled, 0);
+EXTERN  INIT(   int     ExpressionEvaluationTimeLimit, 0);
+EXTERN  INIT(   volatile sig_atomic_t ExpressionTimeLimitExceeded, 0);
 EXTERN  INIT(   int     IgnoreOnce, 0);
 EXTERN  INIT(   int     SortByTime, 0);
 EXTERN  INIT(   int     SortByDate, 0);

src/init.c

@@ -30,7 +30,6 @@
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <termios.h>
-#include <signal.h>
 
 #ifdef HAVE_INITGROUPS
 #include <grp.h>
@@ -1014,30 +1013,14 @@ AddTrustedUser(char const *username)
     TrustedUsers[NumTrustedUsers] = pwent->pw_uid;
     NumTrustedUsers++;
 }
-static void
-sigalarm(int)
-{
-    write(STDOUT_FILENO, "\nExecution time exceeded.\n", 26);
-    exit(1);
-}
 
 static void
 ProcessLongOption(char const *arg)
 {
-    int t;
     if (!strcmp(arg, "version")) {
         printf("%s\n", VERSION);
         exit(EXIT_SUCCESS);
     }
-    if (sscanf(arg, "max-execution-time=%d", &t) == 1) {
-        if (t <= 0) {
-            fprintf(ErrFp, "%s: Value of --max-execution-time must be positive\n", ArgV[0]);
-            return;
-        }
-        signal(SIGALRM, sigalarm);
-        alarm(t);
-        return;
-    }
     fprintf(ErrFp, "%s: Unknown long option --%s\n", ArgV[0], arg);
 }
 

src/main.c

@@ -67,6 +67,13 @@ exitfunc(void)
     fflush(stderr);
 }
 
+static void sigalrm(int)
+{
+    if (ExpressionEvaluationTimeLimit) {
+        ExpressionTimeLimitExceeded = 1;
+    }
+}
+
 /***************************************************************/
 /***************************************************************/
 /**                                                           **/
@@ -78,6 +85,8 @@ int main(int argc, char *argv[])
 {
     int pid;
 
+    struct sigaction act;
+
 #ifdef HAVE_SETLOCALE
     setlocale(LC_ALL, "");
 #endif
@@ -90,6 +99,15 @@ int main(int argc, char *argv[])
     ArgV = (char const **) argv;
 
     InitRemind(argc, (char const **) argv);
+
+    act.sa_handler = sigalrm;
+    sigemptyset(&act.sa_mask);
+    if (sigaction(SIGALRM, &act, NULL) < 0) {
+        fprintf(stderr, "%s: sigaction() failed: %s\n",
+                argv[0], strerror(errno));
+        exit(1);
+    }
+
     DBufInit(&(LastTrigger.tags));
     ClearLastTriggers();
 
@@ -676,7 +694,7 @@ int EvaluateExpr(ParsePtr p, Value *v)
         return E_SWERR;
     }
 
-    r = evaluate_expr_node(node, NULL, v, &nonconst);
+    r = evaluate_expression(node, NULL, v, &nonconst);
     free_expr_tree(node);
     if (r) return r;
     if (nonconst) {

src/protos.h

@@ -59,6 +59,7 @@ int ParseLiteralDate (char const **s, int *dse, int *tim);
 int ParseLiteralTime (char const **s, int *tim);
 expr_node *parse_expression(char const **e, int *r, Var *locals);
 
+int evaluate_expression(expr_node *node, Value *locals, Value *ans, int *nonconst);
 int evaluate_expr_node(expr_node *node, Value *locals, Value *ans, int *nonconst);
 void print_expr_tree(expr_node *node, FILE *fp);
 expr_node *free_expr_tree(expr_node *node);

src/queue.c

@@ -310,6 +310,9 @@ void HandleQueuedReminders(void)
     struct sigaction sa;
     char qid[64];
 
+    /* Disable any potential pending SIGALRMs */
+    alarm(0);
+
     /* Turn off sorting -- otherwise, TriggerReminder has no effect! */
     SortByDate = 0;
 

src/var.c

@@ -319,6 +319,28 @@ static int datetime_sep_func(int do_set, Value *val)
     return OK;
 }
 
+static int expr_time_limit_func(int do_set, Value *val)
+{
+    if (!do_set) {
+        val->type = INT_TYPE;
+        val->v.val = ExpressionEvaluationTimeLimit;
+        return OK;
+    }
+    if (val->type != INT_TYPE) return E_BAD_TYPE;
+    if (val->v.val < 0) return E_2LOW;
+
+    if (!TopLevel()) {
+        /* Ignore attempts to set from non-toplevel unless it's
+           lower than current value */
+        if (val->v.val <= ExpressionEvaluationTimeLimit) {
+            return OK;
+        }
+    }
+
+    ExpressionEvaluationTimeLimit = val->v.val;
+    return OK;
+}
+
 static int default_color_func(int do_set, Value *val)
 {
     int col_r, col_g, col_b;
@@ -808,6 +830,7 @@ static SysVar SysVarArr[] = {
     {"DontTrigAts",    0,  INT_TYPE,     &DontIssueAts,        0,      0 },
     {"EndSent",        1,  STR_TYPE,     &EndSent,             0,      0 },
     {"EndSentIg",      1,  STR_TYPE,     &EndSentIg,           0,      0 },
+    {"ExpressionTimeLimit", 1, SPECIAL_TYPE, expr_time_limit_func, 0,  0 },
     {"February",       1,  STR_TYPE,     &DynamicMonthName[1], 0,      0 },
     {"FirstIndent",    1,  INT_TYPE,     &FirstIndent,         0,      132 },
     {"FoldYear",       1,  INT_TYPE,     &FoldYear,            0,      1 },