[PATCH] D14933: Add the allocsize attribute to LLVM

[Ahmed Bougacha via llvm-commits]

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ab added a comment.

http://reviews.llvm.org/D16390 is indeed quite repulsive; what do you think of annotating the callsites instead?

It does increase bitcode size, but perhaps something like this would feel more natural:

  define i8* @checked_malloc(i32 %N) {
  	%1 = call i8* @object_malloc(i32 %N)
  	%2 = call i32 @llvm.objectsize.i32.p0i8(i8* %1)
  	%max = add i32 %N, 8
  	%c = icmp ule %max, %2
  	call void @llvm.assume(i1 %c)
  	%3 = icmp lt %2, %N
  	br i1 %3, label %Trap, label %Return
  	...
  }

You could also introduce dedicated intrinsics (and maybe even wrap the calls with them, to make the lookup trivial).


http://reviews.llvm.org/D14933