[llvm-commits] [llvm-gcc-4.2] r59021 - in /llvm-gcc-4.2/trunk/gcc: common.opt config/darwin.c

[Evan Cheng]

Hi Bill,

On Nov 10, 2008, at 8:28 PM, Bill Wendling wrote:

> Author: void
> Date: Mon Nov 10 22:28:21 2008
> New Revision: 59021
>
> URL: http://llvm.org/viewvc/llvm-project?rev=59021&view=rev
> Log:
> - Enable stack protectors by default for Darwin 10.6 and later.
> - Don't enable stack protectors by default for Darwin 10.5.
>
> This isn't exact. If we're building a 10.5 binary on a 10.6 system,  
> then stack
> protectors should be enabled.
>
> Modified:
>    llvm-gcc-4.2/trunk/gcc/common.opt
>    llvm-gcc-4.2/trunk/gcc/config/darwin.c
>
> Modified: llvm-gcc-4.2/trunk/gcc/common.opt
> URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/common.opt?rev=59021&r1=59020&r2=59021&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm-gcc-4.2/trunk/gcc/common.opt (original)
> +++ llvm-gcc-4.2/trunk/gcc/common.opt Mon Nov 10 22:28:21 2008
> @@ -1018,9 +1018,8 @@
> -fstack-limit-symbol=<name>	Trap if the stack goes past symbol <name>
>
> ; APPLE LOCAL begin stack-protector default 5095227
> -; LLVM LOCAL FIXME Don't add Init just yet
> fstack-protector
> -Common Report Var(flag_stack_protect, 1)
> +Common Report Var(flag_stack_protect, 1) Init(-1)
> Use propolice as a stack protection method
> ; APPLE LOCAL end stack-protector default 5095227
>
>
> Modified: llvm-gcc-4.2/trunk/gcc/config/darwin.c
> URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/config/darwin.c?rev=59021&r1=59020&r2=59021&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm-gcc-4.2/trunk/gcc/config/darwin.c (original)
> +++ llvm-gcc-4.2/trunk/gcc/config/darwin.c Mon Nov 10 22:28:21 2008
> @@ -2686,12 +2686,22 @@
>   /* APPLE LOCAL begin stack-protector default 5095227 */
>   /* Default flag_stack_protect to 1 if on 10.5 or later for user  
> code,
>      or 10.6 or later for code identified as part of the kernel.  */
> +  /* LLVM LOCAL begin - Don't enable stack protectors by default  
> for Leopard. */
> +#ifndef ENABLE_LLVM

The logic here should be the same for gcc and llvm-gcc. It seems like  
gcc turns it on for 10.5 but when I tried gcc-4.2 it doesn't seem to  
generate stack protector code. Is darwin_macosx_version_min set by  
default? If not, then flag_stack_protect is set somewhere else, right?

>
>   if (flag_stack_protect == -1
>       && darwin_macosx_version_min
>       && ((! flag_mkernel && ! flag_apple_kext
> 	   && strverscmp (darwin_macosx_version_min, "10.5") >= 0)
> 	  || strverscmp (darwin_macosx_version_min, "10.6") >= 0))
>     flag_stack_protect = 1;
> +#else
> +  if (flag_stack_protect == -1 && darwin_macosx_version_min)

Need { } around the if else otherwise it generates a gcc compile  
warning which breaks Apple style build.

Evan

>
> +    if (strverscmp (darwin_macosx_version_min, "10.5") >= 0)
>
> +      flag_stack_protect = 0;
> +    else if (strverscmp (darwin_macosx_version_min, "10.6") >= 0)
> +      flag_stack_protect = 1;
> +#endif
>
> +  /* LLVM LOCAL end - Don't enable stack protectors by default for  
> Leopard. */
>   /* APPLE LOCAL end stack-protector default 5095227 */
> /* APPLE LOCAL diff confuses me */
> }
>
>
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