[llvm] r253116 - [ShrinkWrapping] Disable the optimization for functions with sanitize like

[Quentin Colombet via llvm-commits]

Author: qcolombet
Date: Fri Nov 13 19:55:17 2015
New Revision: 253116

URL: http://llvm.org/viewvc/llvm-project?rev=253116&view=rev
Log:
[ShrinkWrapping] Disable the optimization for functions with sanitize like
attribute.

Even if the target supports shrink-wrapping, the prologue and epilogue
must not move because a crash can happen anywhere and sanitizers need
to be able to unwind from the PC of the crash.

Added:
    llvm/trunk/test/CodeGen/X86/x86-sanitizer-shrink-wrapping.ll
Modified:
    llvm/trunk/lib/CodeGen/ShrinkWrap.cpp

Modified: llvm/trunk/lib/CodeGen/ShrinkWrap.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ShrinkWrap.cpp?rev=253116&r1=253115&r2=253116&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ShrinkWrap.cpp (original)
+++ llvm/trunk/lib/CodeGen/ShrinkWrap.cpp Fri Nov 13 19:55:17 2015
@@ -468,7 +468,14 @@ bool ShrinkWrap::isShrinkWrapEnabled(con
     return TFI->enableShrinkWrapping(MF) &&
       // Windows with CFI has some limitations that make it impossible
       // to use shrink-wrapping.
-      !MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
+      !MF.getTarget().getMCAsmInfo()->usesWindowsCFI() &&
+      // Sanitizers look at the value of the stack at the location
+      // of the crash. Since a crash can happen anywhere, the
+      // frame must be lowered before anything else happen for the
+      // sanitizers to be able to get a correct stack frame.
+      !(MF.getFunction()->hasFnAttribute(Attribute::SanitizeAddress) ||
+        MF.getFunction()->hasFnAttribute(Attribute::SanitizeThread) ||
+        MF.getFunction()->hasFnAttribute(Attribute::SanitizeMemory));
   // If EnableShrinkWrap is set, it takes precedence on whatever the
   // target sets. The rational is that we assume we want to test
   // something related to shrink-wrapping.

Added: llvm/trunk/test/CodeGen/X86/x86-sanitizer-shrink-wrapping.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/x86-sanitizer-shrink-wrapping.ll?rev=253116&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/x86-sanitizer-shrink-wrapping.ll (added)
+++ llvm/trunk/test/CodeGen/X86/x86-sanitizer-shrink-wrapping.ll Fri Nov 13 19:55:17 2015
@@ -0,0 +1,40 @@
+; RUN: llc -o - < %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "x86_64-apple-macosx"
+
+; Even if the target supports shrink-wrapping, the prologue and epilogue
+; must not move because a crash can happen anywhere and sanitizers need
+; to be able to unwind from the PC of the crash.
+; CHECK-LABEL: sanitize:
+; CHECK: pushq
+; CHECK: incl 40
+; CHECK: popq
+; CHECK-NEXT: retq
+; CHECK: movl $40, %edi
+; CHECK-NEXT callq ___asan_report_load4
+define  void @sanitize() #0 {
+entry:
+  %tmp = load i8, i8* inttoptr (i64 17592186044421 to i8*)
+  %tmp1 = icmp ne i8 %tmp, 0
+  br i1 %tmp1, label %if.then, label %else
+
+if.then:
+  %tmp3 = icmp sge i8 3, %tmp
+  br i1 %tmp3, label %else, label %end
+
+else:
+  call void @__asan_report_load4(i64 40)
+  call void asm sideeffect "", ""()
+  unreachable
+
+end:
+  %tmp6 = load i32, i32* inttoptr (i64 40 to i32*), align 8
+  %inc = add nsw i32 %tmp6, 1
+  store i32 %inc, i32* inttoptr (i64 40 to i32*), align 8
+  ret void
+}
+
+attributes #0 = { sanitize_address nounwind "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" }
+
+declare void @__asan_report_load4(i64)