From e224950cf48abe0a0d439fb8d4f154fe59984de7 Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Sun, 7 Dec 2014 16:22:51 -0500
Subject: [PATCH] Some allocator cleanup in the new Table.

---
 wintable/new/main.c |  8 ++------
 wintable/new/util.h | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/wintable/new/main.c b/wintable/new/main.c
index cd0b906..4e2663f 100644
--- a/wintable/new/main.c
+++ b/wintable/new/main.c
@@ -72,11 +72,7 @@ static LRESULT CALLBACK tableWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM
 		if (uMsg == WM_NCCREATE) {
 			CREATESTRUCTW *cs = (CREATESTRUCTW *) lParam;
 
-			// TODO find something that DOES set a last error code to use instead, or figure out how to abuse SEH temporarily so we can use HeapAlloc()...
-			t = (struct table *) malloc(sizeof (struct table));
-			if (t == NULL)
-				panic("error allocating internal Table data structure");
-			ZeroMemory(t, sizeof (struct table));
+			t = (struct table *) tableAlloc(sizeof (struct table), "error allocating internal Table data structure");
 			t->hwnd = hwnd;
 			SetWindowLongPtrW(hwnd, GWLP_USERDATA, (LONG_PTR) t);
 		}
@@ -87,7 +83,7 @@ static LRESULT CALLBACK tableWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM
 	if (uMsg == WM_DESTROY) {
 		// TODO free appropriate (after figuring this part out) components of t
 		// TODO send DESTROY events to accessibility listeners (when appropriate)
-		free(t);
+		tableFree(t, "error allocating internal Table data structure");
 		return DefWindowProcW(hwnd, uMsg, wParam, lParam);
 	}
 	if (runHandlers(handlers, t, uMsg, wParam, lParam, &lResult))
diff --git a/wintable/new/util.h b/wintable/new/util.h
index 2bcfd94..dc51605 100644
--- a/wintable/new/util.h
+++ b/wintable/new/util.h
@@ -12,3 +12,37 @@ static BOOL runHandlers(const handlerfunc list[], struct table *t, UINT uMsg, WP
 			return TRUE;
 	return FALSE;
 }
+
+// memory allocation stuff
+// each of these functions do an implicit ZeroMemory()
+// we're using LocalAlloc() because:
+// - whether the malloc() family supports the last-error code is undefined
+// - the HeapAlloc() family DOES NOT support the last-error code; you're supposed to use Windows exceptions, and I can't find a clean way to do this with MinGW-w64 that doesn't rely on inline assembly or external libraries (unless they added __try/__except blocks)
+// - there's no VirtualReAlloc() to complement VirtualAlloc() and I'm not sure if we can even get the original allocated size back out reliably to write it ourselves (http://blogs.msdn.com/b/oldnewthing/archive/2012/03/16/10283988.aspx)
+// needless to say, TODO
+
+static void *tableAlloc(size_t size, const char *panicMessage)
+{
+	HLOCAL out;
+
+	out = LocalAlloc(LMEM_FIXED | LMEM_ZEROINIT, size);
+	if (out == NULL)
+		panic(panicMessage);
+	return (void *) out;
+}
+
+static void *tableRealloc(void *p, size_t size, const char *panicMessage)
+{
+	HLOCAL out;
+
+	out = LocalReAlloc((HLOCAL) p, size, LMEM_ZEROINIT);
+	if (out == NULL)
+		panic(panicMessage);
+	return (void *) out;
+}
+
+static void tableFree(void *p, const char *panicMessage)
+{
+	if (LocalFree((HLOCAL) p) != NULL)
+		panic(panicMessage);
+}