Initial entry

util/int/segment.c

@@ -0,0 +1,84 @@
+/*
+	AB_list[s] holds the actual base of stack frame  s; this
+	is the highest stack pointer of frame  s-1.
+	Segments have the following numbers:
+		-2			DATA_SEGMENT
+		-1			HEAP_SEGMENT
+		0, 1, .., curr_frame	stackframes
+	Note that  AB_list[s] increases for decreasing s.
+*/
+
+/* $Header$ */
+
+#include	"segcheck.h"
+#include	"global.h"
+#include	"mem.h"
+#include	"alloc.h"
+
+#ifdef	SEGCHECK
+
+#define	ABLISTSIZE	100L		/* initial AB_list size */
+
+#define	DATA_SEGMENT	-2
+#define	HEAP_SEGMENT	-1
+
+PRIVATE ptr *AB_list;
+PRIVATE size frame_limit;
+PRIVATE size curr_frame;
+
+init_AB_list() {
+	/* Allocate space for AB_list & initialize frame variables */
+
+	frame_limit = ABLISTSIZE;
+	curr_frame = 0L;
+	AB_list = (ptr *) Malloc(frame_limit * sizeof (ptr), "AB_list");
+	AB_list[curr_frame] = AB;
+}
+
+push_frame(p)
+	ptr p;
+{
+	if (++curr_frame == frame_limit) {
+		frame_limit = allocfrac(frame_limit);
+		AB_list = (ptr *) Realloc((char *) AB_list,
+				frame_limit * sizeof (ptr), "AB_list");
+	}
+	AB_list[curr_frame] = p;
+}
+
+pop_frames() {
+	while (AB_list[curr_frame] < AB) {
+		curr_frame--;
+	}
+}
+
+int ptr2seg(p)
+	ptr p;
+{
+	register int s;
+
+	if (in_gda(p)) {
+		s = DATA_SEGMENT;
+	}
+	else if (!in_stack(p)) {
+		s = HEAP_SEGMENT;
+	}
+	else {
+		for (s = curr_frame; s > 0; s--) {
+			if (AB_list[s] > p)
+				break;
+		}
+	}
+	return s;
+}
+
+#else	SEGCHECK
+
+init_AB_list() {}
+
+push_frame() {}
+
+pop_frames() {}
+
+#endif	SEGCHECK
+