Add sane default memory hook to Cytoplasm, fix more leaks in json.

src/Log.c

@@ -124,7 +124,6 @@ LogConfigFree(LogConfig * config)
     }
 
     pthread_mutex_destroy(&config->lock);
-    Free(config->tsFmt);
     Free(config);
 
     if (config == globalConfig)

src/Memory.c

@@ -27,6 +27,9 @@
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <signal.h>
+
+#include <unistd.h>
 #include <pthread.h>
 
 #include <Int.h>
@@ -458,6 +461,64 @@ void
     pthread_mutex_unlock(&lock);
 }
 
+static size_t
+HexPtr(unsigned long ptr, char *out, size_t len)
+{
+    size_t i = len - 1;
+    size_t j = 0;
+
+    do
+    {
+        out[i] = "0123456789abcdef"[ptr % 16];
+        i--;
+        ptr /= 16;
+    } while (ptr > 0);
+
+    while (++i < len)
+    {
+        out[j++] = out[i];
+    }
+
+    out[j] = '\0';
+
+    return j;
+}
+
+void
+MemoryDefaultHook(MemoryAction a, MemoryInfo * i, void *args)
+{
+    char buf[64];
+    unsigned long ptr = (unsigned long) MemoryInfoGetPointer(i);
+
+    size_t len = HexPtr(ptr, buf, sizeof(buf));
+
+    (void) args;
+
+    switch (a)
+    {
+        case MEMORY_BAD_POINTER:
+            write(STDERR_FILENO, "Bad pointer: 0x", 15);
+            break;
+        case MEMORY_CORRUPTED:
+            write(STDERR_FILENO, "Corrupted block: 0x", 19);
+            break;
+        default:
+            return;
+    }
+
+    write(STDERR_FILENO, buf, len);
+    write(STDERR_FILENO, " to 0x", 6);
+    len = HexPtr(MemoryInfoGetSize(i), buf, sizeof(buf));
+    write(STDERR_FILENO, buf, len);
+    write(STDERR_FILENO, " bytes at ", 10);
+    write(STDERR_FILENO, MemoryInfoGetFile(i), strlen(MemoryInfoGetFile(i)));
+    write(STDERR_FILENO, ":0x", 3);
+    len = HexPtr(MemoryInfoGetLine(i), buf, sizeof(buf));
+    write(STDERR_FILENO, buf, len);
+    write(STDERR_FILENO, "\n", 1);
+    raise(SIGSEGV);
+}
+
 void
  MemoryHexDump(MemoryInfo * info, void (*printFunc) (size_t, char *, char *, void *), void *args)
 {

src/RtStub.c

@@ -70,6 +70,8 @@ main(int argc, char **argv)
 
     MainArgs args;
 
+    MemoryHook(MemoryDefaultHook, NULL);
+
     args.args = NULL;
     args.env = NULL;
 

src/include/Memory.h

@@ -199,6 +199,15 @@ extern void MemoryIterate(void (*) (MemoryInfo *, void *), void *);
  */
 extern void MemoryHook(void (*) (MemoryAction, MemoryInfo *, void *), void *);
 
+/**
+ * The default memory hook, which has sane behavior and is installed
+ * at runtime. This function does not use any memory on the heap,
+ * except for the MemoryInfo passed to it, which it assumes to be
+ * valid. Everything else happens on the stack only, to ensure that
+ * the hook doesn't make any memory problems worse.
+ */
+extern void MemoryDefaultHook(MemoryAction, MemoryInfo *, void *);
+
 /**
  * Read over the block of memory represented by the given memory info
  * structure and generate a hexadecimal and ASCII string for each