X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/9786185611c072036751fdfcc1731158a0c2d20c..898aa30bfb038ffeca54d6dea95f0f80fbc08f7f:/t/errmemwrap.c

diff --git a/t/errmemwrap.c b/t/errmemwrap.c
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--- /dev/null
+++ b/t/errmemwrap.c
@@ -0,0 +1,131 @@
+/*
+ * Allocation wrapper for test purposes.
+ *
+ * Copyright © 2024 Nick Bowler
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#ifndef TEST_MALLOC_HOOK
+#  define TEST_MALLOC_HOOK 1
+#endif
+#include "cdecl-internal.h"
+#undef malloc
+
+static union test_alloc {
+	union test_alloc *p;
+	max_align_t a;
+	size_t v;
+} *alloc_head;
+
+enum {
+	ALLOC_NEXT_PTR,
+	ALLOC_STATE,
+	ALLOC_SIZE,
+	ALLOC_PAYLOAD
+};
+
+#define ALLOC_STATE_ALLOCATED 0x7143u
+#define ALLOC_STATE_FREED     0xdeadu
+
+/*
+ * Hook for testing allocation behaviour of the library, enabling a basic
+ * verification in test cases that the library does not leak memory.
+ *
+ * The library sources must be recompiled with -DTEST_MALLOC_HOOK to
+ * make use of this functionality.
+ *
+ * In this implementation, allocated memory is never freed, instead just
+ * marked with an indication that the memory is no longer live.
+ */
+void *test_realloc_hook(void *p, size_t n)
+{
+	union test_alloc *old_alloc = p, *alloc;
+
+	if (old_alloc) {
+		old_alloc = &old_alloc[-ALLOC_PAYLOAD];
+		if (old_alloc[ALLOC_STATE].v != ALLOC_STATE_ALLOCATED) {
+			printf("Bail out! %p is not a live allocation!\n", p);
+			exit(99);
+		}
+
+		old_alloc[ALLOC_STATE].v = ALLOC_STATE_FREED;
+		printf("# %p freed\n", p);
+	}
+
+	if (!n)
+		return NULL;
+
+	n = (n + sizeof *alloc - 1) / sizeof *alloc;
+	alloc = malloc((n + ALLOC_PAYLOAD) * sizeof *alloc);
+	if (!alloc)
+		return NULL;
+
+	alloc[ALLOC_NEXT_PTR].p = alloc_head;
+	alloc_head = alloc;
+
+	alloc[ALLOC_STATE].v = ALLOC_STATE_ALLOCATED;
+	alloc[ALLOC_SIZE].v  = n * sizeof *alloc;
+
+	if (old_alloc) {
+		n = old_alloc[ALLOC_SIZE].v;
+		memcpy(&alloc[ALLOC_PAYLOAD], &old_alloc[ALLOC_PAYLOAD], n);
+	}
+
+	p = &alloc[ALLOC_PAYLOAD];
+	printf("# %p allocated\n", p);
+	return p;
+}
+
+/*
+ * Returns the total number of allocations that have not yet been freed.
+ */
+size_t test_live_allocations(void)
+{
+	union test_alloc *a;
+	size_t ret = 0;
+
+	for (a = alloc_head; a; a = a[ALLOC_NEXT_PTR].p) {
+		void *p = &a[ALLOC_PAYLOAD];
+
+		switch (a[ALLOC_STATE].v) {
+		case ALLOC_STATE_ALLOCATED:
+			printf("# %p still live\n", p);
+			ret++;
+			break;
+		case ALLOC_STATE_FREED:
+			break;
+		default:
+			printf("Bail out! detected %p state corruption\n", p);
+			exit(99);
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Function called from output.c but not needed for error messaging
+ * (only current user of this file)
+ */
+const char *cdecl__token_name(unsigned token)
+{
+	printf("Bail out! stub cdecl__token_name called\n");
+	exit(99);
+}