mirror of https://github.com/acidanthera/audk.git
810c635d6f
For pointer subtraction, the result is of type "ptrdiff_t". According to the C11 standard (Committee Draft - April 12, 2011): "When two pointers are subtracted, both shall point to elements of the same array object, or one past the last element of the array object; the result is the difference of the subscripts of the two array elements. The size of the result is implementation-defined, and its type (a signed integer type) is ptrdiff_t defined in the <stddef.h> header. If the result is not representable in an object of that type, the behavior is undefined." In our codes, there are cases that the pointer subtraction is not performed by pointers to elements of the same array object. This might lead to potential issues, since the behavior is undefined according to C11 standard. Also, since the size of type "ptrdiff_t" is implementation-defined. Some static code checkers may warn that the pointer subtraction might underflow first and then being cast to a bigger size. For example: UINT8 *Ptr1, *Ptr2; UINTN PtrDiff; ... PtrDiff = (UINTN) (Ptr1 - Ptr2); The commit will refine the pointer subtraction expressions by casting each pointer to UINTN first and then perform the subtraction: PtrDiff = (UINTN) Ptr1 - (UINTN) Ptr2; Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Hao Wu <hao.a.wu@intel.com> Acked-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Jaben Carsey <jaben.carsey@intel.com> |
||
|---|---|---|
| .. | ||
| Application | ||
| Include | ||
| Library | ||
| Contributions.txt | ||
| License.txt | ||
| Readme.txt | ||
| ShellPkg.dec | ||
| ShellPkg.dsc | ||
Readme.txt
============================================================================ OVERVIEW ============================================================================ The UEFI 2.0 shell provides a standard pre-boot command line processor. It is similar to the EDK EFI Shell or a *nix command line parser. ============================================================================ HOW TO INCORPORATE THIS SHELL INTO NT32 ============================================================================ The instructions below are included as a sample and template on how a developer may integrate this code into an existing platform: 1. Add this shell build to the NT32 build: Add the shell.inf to the [components] section as it is in the ShellPkg.dsc. 2. Update system PCDs to support this new module Update the PCD as follows using the Shell's PCD: gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdShellFile|{ 0x83, 0xA5, 0x04, 0x7C, 0x3E, 0x9E, 0x1C, 0x4F, 0xAD, 0x65, 0xE0, 0x52, 0x68, 0xD0, 0xB4, 0xD1 } 3. Remove the old shell from the NT32 Firmware list Remove the FILE APPLICATION section for the old shell. 4. Add this shell to the NT32 firmware list Add the Shell.INF to the end of the list of DXE modules. 5. Build NT32 ============================================================================