1 files changed, 118 insertions, 0 deletions
diff --git a/chattymalloc.c b/chattymalloc.c
new file mode 100644
index 0000000..db8d2de
--- /dev/null
+++ b/chattymalloc.c
@@ -0,0 +1,118 @@
+#define _GNU_SOURCE
+#include <dlfcn.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+char tmpbuff[1024];
+unsigned long tmppos = 0;
+unsigned long tmpallocs = 0;
+
+void *memset(void*,int,size_t);
+void *memmove(void *to, const void *from, size_t size);
+
+/*=========================================================
+ *  * interception points
+ *  */
+
+static void * (*myfn_calloc)(size_t nmemb, size_t size);
+static void * (*myfn_malloc)(size_t size);
+static void   (*myfn_free)(void *ptr);
+static void * (*myfn_realloc)(void *ptr, size_t size);
+static void * (*myfn_memalign)(size_t blocksize, size_t bytes);
+
+static void init()
+{
+	myfn_malloc     = dlsym(RTLD_NEXT, "malloc");
+	myfn_free       = dlsym(RTLD_NEXT, "free");
+	myfn_calloc     = dlsym(RTLD_NEXT, "calloc");
+	myfn_realloc    = dlsym(RTLD_NEXT, "realloc");
+	myfn_memalign   = dlsym(RTLD_NEXT, "memalign");
+
+	if (!myfn_malloc || !myfn_free || !myfn_calloc || !myfn_realloc || !myfn_memalign)
+	{
+		fprintf(stderr, "Error in `dlsym`: %s\n", dlerror());
+		exit(1);
+	}
+}
+
+void *malloc(size_t size)
+{
+	static int initializing = 0;
+	if (myfn_malloc == NULL)
+	{
+		if (!initializing)
+		{
+			initializing = 1;
+			init();
+			initializing = 0;
+
+			fprintf(stdout, "jcheck: allocated %lu bytes of temp memory in %lu chunks during initialization\n", tmppos, tmpallocs);
+		}
+		else
+		{
+			if (tmppos + size < sizeof(tmpbuff))
+			{
+				void *retptr = tmpbuff + tmppos;
+				tmppos += size;
+				++tmpallocs;
+				return retptr;
+			}
+			else
+			{
+				fprintf(stdout, "jcheck: too much memory requested during initialisation - increase tmpbuff size\n");
+				exit(1);
+			}
+		}
+	}
+
+	fprintf(stderr, "%d\n", size);
+	void *ptr = myfn_malloc(size);
+	return ptr;
+}
+
+void free(void *ptr)
+{
+	// something wrong if we call free before one of the allocators!
+	if (myfn_malloc == NULL)
+		init();
+	if (ptr >= (void*) tmpbuff && ptr <= (void*)(tmpbuff + tmppos))
+		fprintf(stdout, "freeing temp memory\n");
+	else
+		myfn_free(ptr);
+}
+
+void *realloc(void *ptr, size_t size)
+{
+	if (myfn_malloc == NULL)
+	{
+		void *nptr = malloc(size);
+		if (nptr && ptr)
+		{
+			memmove(nptr, ptr, size);
+			free(ptr);
+		}
+		return nptr;
+	}
+	void *nptr = myfn_realloc(ptr, size);
+	return nptr;
+}
+
+void *calloc(size_t nmemb, size_t size)
+{
+	if (myfn_malloc == NULL)
+	{
+		void *ptr = malloc(nmemb*size);
+		if (ptr)
+		memset(ptr, 0, nmemb*size);
+		return ptr;
+	}
+	void *ptr = myfn_calloc(nmemb, size);
+	return ptr;
+}
+
+void *memalign(size_t blocksize, size_t bytes)
+{
+	void *ptr = myfn_memalign(blocksize, bytes);
+	return ptr;
+}