185 lines
7.2 KiB
OpenEdge ABL
185 lines
7.2 KiB
OpenEdge ABL
|
/*++
|
||
|
|
|
||
|
|
Copyright (c) 2001 Microsoft Corporation
|
||
|
|
|
||
|
|
Module Name:
|
||
|
|
|
||
|
|
alloca.h
|
||
|
|
|
||
|
|
Abstract:
|
||
|
|
|
||
|
|
This module implements a safe stack-based allocator with fallback to the heap.
|
||
|
|
|
||
|
|
Author:
|
||
|
|
|
||
|
|
Jonathan Schwartz (JSchwart) 16-Mar-2001
|
||
|
|
|
||
|
|
Revision History:
|
||
|
|
|
||
|
|
--*/
|
||
|
|
|
||
|
|
#ifndef _SAFEALLOCA_H_
|
||
|
|
#define _SAFEALLOCA_H_
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
extern "C"
|
||
|
|
{
|
||
|
|
#endif // __cplusplus
|
||
|
|
|
||
|
|
|
||
|
|
#include <align.h> // ALIGN_WORST
|
||
|
|
|
||
|
|
|
||
|
|
//
|
||
|
|
// Type definitions
|
||
|
|
//
|
||
|
|
|
||
|
|
typedef ULONG SAFEALLOCA_HEADER;
|
||
|
|
|
||
|
|
typedef PVOID (APIENTRY *SAFEALLOC_ALLOC_PROC)(
|
||
|
|
SIZE_T Size
|
||
|
|
);
|
||
|
|
|
||
|
|
typedef VOID (APIENTRY *SAFEALLOC_FREE_PROC)(
|
||
|
|
PVOID BaseAddress
|
||
|
|
);
|
||
|
|
|
||
|
|
|
||
|
|
//
|
||
|
|
// Constant definitions
|
||
|
|
//
|
||
|
|
|
||
|
|
#define SAFEALLOCA_STACK_HEADER ((SAFEALLOCA_HEADER) 0x6b637453) /* "Stck" */
|
||
|
|
#define SAFEALLOCA_HEAP_HEADER ((SAFEALLOCA_HEADER) 0x70616548) /* "Heap" */
|
||
|
|
|
||
|
|
#define SAFEALLOCA_USE_DEFAULT 0xdeadbeef
|
||
|
|
|
||
|
|
//
|
||
|
|
// We'll be adding ALIGN_WORST bytes to the allocation size to add room for
|
||
|
|
// the SAFEALLOCA_HEADER -- make sure we'll always have enough space.
|
||
|
|
//
|
||
|
|
|
||
|
|
C_ASSERT(sizeof(SAFEALLOCA_HEADER) <= ALIGN_WORST);
|
||
|
|
|
||
|
|
|
||
|
|
//
|
||
|
|
// Per-DLL SafeAlloca globals
|
||
|
|
//
|
||
|
|
|
||
|
|
extern SIZE_T g_ulMaxStackAllocSize;
|
||
|
|
extern SIZE_T g_ulAdditionalProbeSize;
|
||
|
|
|
||
|
|
extern SAFEALLOC_ALLOC_PROC g_pfnAllocate;
|
||
|
|
extern SAFEALLOC_FREE_PROC g_pfnFree;
|
||
|
|
|
||
|
|
|
||
|
|
//
|
||
|
|
// Functions defined in alloca.lib
|
||
|
|
//
|
||
|
|
|
||
|
|
VOID
|
||
|
|
SafeAllocaInitialize(
|
||
|
|
IN OPTIONAL SIZE_T ulMaxStackAllocSize,
|
||
|
|
IN OPTIONAL SIZE_T ulAdditionalProbeSize,
|
||
|
|
IN OPTIONAL SAFEALLOC_ALLOC_PROC pfnAllocate,
|
||
|
|
IN OPTIONAL SAFEALLOC_FREE_PROC pfnFree
|
||
|
|
);
|
||
|
|
|
||
|
|
BOOL
|
||
|
|
VerifyStackAvailable(
|
||
|
|
SIZE_T Size
|
||
|
|
);
|
||
|
|
|
||
|
|
|
||
|
|
//
|
||
|
|
// Usage:
|
||
|
|
//
|
||
|
|
// VOID
|
||
|
|
// SafeAllocaAllocate(
|
||
|
|
// PVOID PtrVar,
|
||
|
|
// SIZE_T BlockSize
|
||
|
|
// );
|
||
|
|
//
|
||
|
|
// (PtrVar == NULL) on failure
|
||
|
|
//
|
||
|
|
|
||
|
|
#define SafeAllocaAllocate(PtrVar, BlockSize) \
|
||
|
|
\
|
||
|
|
{ \
|
||
|
|
PVOID *ppvAvoidCast = (PVOID *) &(PtrVar); \
|
||
|
|
\
|
||
|
|
(PtrVar) = NULL; \
|
||
|
|
\
|
||
|
|
/* Make sure block is below the threshhold and that the probe won't overflow */ \
|
||
|
|
\
|
||
|
|
if ((BlockSize) <= g_ulMaxStackAllocSize \
|
||
|
|
&& \
|
||
|
|
((BlockSize) + g_ulAdditionalProbeSize >= (BlockSize))) \
|
||
|
|
{ \
|
||
|
|
if (VerifyStackAvailable((BlockSize) \
|
||
|
|
+ g_ulAdditionalProbeSize \
|
||
|
|
+ ALIGN_WORST)) \
|
||
|
|
{ \
|
||
|
|
/* \
|
||
|
|
* Don't need to wrap with try-except since we just probed \
|
||
|
|
*/ \
|
||
|
|
\
|
||
|
|
*ppvAvoidCast = _alloca((BlockSize) + ALIGN_WORST); \
|
||
|
|
} \
|
||
|
|
\
|
||
|
|
if ((PtrVar) != NULL) \
|
||
|
|
{ \
|
||
|
|
*((SAFEALLOCA_HEADER *) (PtrVar)) = SAFEALLOCA_STACK_HEADER; \
|
||
|
|
*ppvAvoidCast = ((LPBYTE) (PtrVar) + ALIGN_WORST); \
|
||
|
|
} \
|
||
|
|
} \
|
||
|
|
\
|
||
|
|
/* \
|
||
|
|
* Stack allocation failed -- try the heap \
|
||
|
|
*/ \
|
||
|
|
\
|
||
|
|
if ((PtrVar) == NULL) \
|
||
|
|
{ \
|
||
|
|
*ppvAvoidCast = g_pfnAllocate((BlockSize) + ALIGN_WORST); \
|
||
|
|
\
|
||
|
|
if ((PtrVar) != NULL) \
|
||
|
|
{ \
|
||
|
|
*((SAFEALLOCA_HEADER *) (PtrVar)) = SAFEALLOCA_HEAP_HEADER; \
|
||
|
|
*ppvAvoidCast = ((LPBYTE) (PtrVar) + ALIGN_WORST); \
|
||
|
|
} \
|
||
|
|
} \
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
//
|
||
|
|
// Usage:
|
||
|
|
//
|
||
|
|
// VOID
|
||
|
|
// SafeAllocaFree(
|
||
|
|
// PVOID PtrVar,
|
||
|
|
// );
|
||
|
|
//
|
||
|
|
|
||
|
|
#define SafeAllocaFree(PtrVar) \
|
||
|
|
\
|
||
|
|
if (PtrVar != NULL) \
|
||
|
|
{ \
|
||
|
|
SAFEALLOCA_HEADER *Tag = (SAFEALLOCA_HEADER *) ((LPBYTE) (PtrVar) \
|
||
|
|
- ALIGN_WORST); \
|
||
|
|
\
|
||
|
|
if (*(SAFEALLOCA_HEADER *) (Tag) == SAFEALLOCA_HEAP_HEADER) \
|
||
|
|
{ \
|
||
|
|
g_pfnFree(Tag); \
|
||
|
|
} \
|
||
|
|
else \
|
||
|
|
{ \
|
||
|
|
ASSERT(*(SAFEALLOCA_HEADER *) (Tag) == SAFEALLOCA_STACK_HEADER); \
|
||
|
|
} \
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
}
|
||
|
|
#endif // __cplusplus
|
||
|
|
|
||
|
|
#endif // _SAFEALLOCA_H_
|