[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).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182375 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evgeniy Stepanov 2013-05-21 12:27:47 +00:00
parent f8cd1ee516
commit bf4150656f
3 changed files with 39 additions and 2 deletions

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@ -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 VarArgHelper {
}
};
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

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@ -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*)

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@ -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