[llvm] r182375 - [msan] A no-op implementation of VarArg handling.

[Evgeniy Stepanov]

Author: eugenis
Date: Tue May 21 07:27:47 2013
New Revision: 182375

URL: http://llvm.org/viewvc/llvm-project?rev=182375&view=rev
Log:
[msan] A no-op implementation of VarArg handling.

This stuff is used on platforms where MSan does not have a proper VarArg
implementation (anything other than x86_64 at the moment).

Added:
    llvm/trunk/test/Instrumentation/MemorySanitizer/X86/
    llvm/trunk/test/Instrumentation/MemorySanitizer/X86/vararg.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
    llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp?rev=182375&r1=182374&r2=182375&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp Tue May 21 07:27:47 2013
@@ -74,6 +74,7 @@
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/ADT/ValueMap.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Function.h"
@@ -1963,9 +1964,29 @@ struct VarArgAMD64Helper : public VarArg
   }
 };
 
-VarArgHelper* CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
+/// \brief A no-op implementation of VarArgHelper.
+struct VarArgNoOpHelper : public VarArgHelper {
+  VarArgNoOpHelper(Function &F, MemorySanitizer &MS,
+                   MemorySanitizerVisitor &MSV) {}
+
+  void visitCallSite(CallSite &CS, IRBuilder<> &IRB) {}
+
+  void visitVAStartInst(VAStartInst &I) {}
+
+  void visitVACopyInst(VACopyInst &I) {}
+
+  void finalizeInstrumentation() {}
+};
+
+VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
                                  MemorySanitizerVisitor &Visitor) {
-  return new VarArgAMD64Helper(Func, Msan, Visitor);
+  // VarArg handling is only implemented on AMD64. False positives are possible
+  // on other platforms.
+  llvm::Triple TargetTriple(Func.getParent()->getTargetTriple());
+  if (TargetTriple.getArch() == llvm::Triple::x86_64)
+    return new VarArgAMD64Helper(Func, Msan, Visitor);
+  else
+    return new VarArgNoOpHelper(Func, Msan, Visitor);
 }
 
 }  // namespace

Added: llvm/trunk/test/Instrumentation/MemorySanitizer/X86/vararg.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/MemorySanitizer/X86/vararg.ll?rev=182375&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/MemorySanitizer/X86/vararg.ll (added)
+++ llvm/trunk/test/Instrumentation/MemorySanitizer/X86/vararg.ll Tue May 21 07:27:47 2013
@@ -0,0 +1,15 @@
+; RUN: opt < %s -msan -msan-check-access-address=0 -S
+; Test that code using va_start can be compiled on i386.
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
+target triple = "i386-unknown-linux-gnu"
+
+define void @VaStart(i8* %s, ...) {
+entry:
+  %vl = alloca i8*, align 4
+  %vl1 = bitcast i8** %vl to i8*
+  call void @llvm.va_start(i8* %vl1)
+  ret void
+}
+
+declare void @llvm.va_start(i8*)

Modified: llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll?rev=182375&r1=182374&r2=182375&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll (original)
+++ llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll Tue May 21 07:27:47 2013
@@ -1,6 +1,7 @@
 ; RUN: opt < %s -msan -msan-check-access-address=0 -S | FileCheck %s
 ; RUN: opt < %s -msan -msan-check-access-address=0 -msan-track-origins=1 -S | FileCheck -check-prefix=CHECK-ORIGINS %s
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
 
 ; Check the presence of __msan_init
 ; CHECK: @llvm.global_ctors {{.*}} @__msan_init