r216638 - Properly handle multiple nonnull attributes in CodeGen
Alexey Samsonov
vonosmas at gmail.com
Wed Aug 27 17:53:21 PDT 2014
Author: samsonov
Date: Wed Aug 27 19:53:20 2014
New Revision: 216638
URL: http://llvm.org/viewvc/llvm-project?rev=216638&view=rev
Log:
Properly handle multiple nonnull attributes in CodeGen
Modified:
cfe/trunk/lib/CodeGen/CGCall.cpp
cfe/trunk/test/CodeGen/nonnull.c
Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=216638&r1=216637&r2=216638&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Wed Aug 27 19:53:20 2014
@@ -1419,6 +1419,30 @@ static llvm::Value *emitArgumentDemotion
return CGF.Builder.CreateFPCast(value, varType, "arg.unpromote");
}
+static bool shouldAddNonNullAttr(const Decl *FD, const ParmVarDecl *PVD) {
+ // FIXME: __attribute__((nonnull)) can also be applied to:
+ // - references to pointers, where the pointee is known to be
+ // nonnull (apparently a Clang extension)
+ // - transparent unions containing pointers
+ // In the former case, LLVM IR cannot represent the constraint. In
+ // the latter case, we have no guarantee that the transparent union
+ // is in fact passed as a pointer.
+ if (!PVD->getType()->isAnyPointerType() &&
+ !PVD->getType()->isBlockPointerType())
+ return false;
+ // First, check attribute on parameter itself.
+ if (PVD->hasAttr<NonNullAttr>())
+ return true;
+ // Check function attributes.
+ if (!FD)
+ return false;
+ for (const auto *NNAttr : FD->specific_attrs<NonNullAttr>()) {
+ if (NNAttr->isNonNull(PVD->getFunctionScopeIndex()))
+ return true;
+ }
+ return false;
+}
+
void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI,
llvm::Function *Fn,
const FunctionArgList &Args) {
@@ -1463,10 +1487,6 @@ void CodeGenFunction::EmitFunctionProlog
llvm::Attribute::NoAlias));
}
- // Get the function-level nonnull attribute if it exists.
- const NonNullAttr *NNAtt =
- CurCodeDecl ? CurCodeDecl->getAttr<NonNullAttr>() : nullptr;
-
// Track if we received the parameter as a pointer (indirect, byval, or
// inalloca). If already have a pointer, EmitParmDecl doesn't need to copy it
// into a local alloca for us.
@@ -1557,17 +1577,7 @@ void CodeGenFunction::EmitFunctionProlog
llvm::Value *V = AI;
if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(Arg)) {
- // FIXME: __attribute__((nonnull)) can also be applied to:
- // - references to pointers, where the pointee is known to be
- // nonnull (apparently a Clang extension)
- // - transparent unions containing pointers
- // In the former case, LLVM IR cannot represent the constraint. In
- // the latter case, we have no guarantee that the transparent union
- // is in fact passed as a pointer.
- if (((NNAtt && NNAtt->isNonNull(PVD->getFunctionScopeIndex())) ||
- PVD->hasAttr<NonNullAttr>()) &&
- (PVD->getType()->isAnyPointerType() ||
- PVD->getType()->isBlockPointerType()))
+ if (shouldAddNonNullAttr(CurCodeDecl, PVD))
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1,
llvm::Attribute::NonNull));
Modified: cfe/trunk/test/CodeGen/nonnull.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/nonnull.c?rev=216638&r1=216637&r2=216638&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/nonnull.c (original)
+++ cfe/trunk/test/CodeGen/nonnull.c Wed Aug 27 19:53:20 2014
@@ -41,3 +41,11 @@ typedef union {
int bar6(TransparentUnion tu) __attribute__((nonnull(1))) {
return *tu.p;
}
+
+// CHECK: define void @bar7(i32* nonnull %a, i32* nonnull %b)
+void bar7(int *a, int *b) __attribute__((nonnull(1)))
+__attribute__((nonnull(2))) {}
+
+// CHECK: define void @bar8(i32* nonnull %a, i32* nonnull %b)
+void bar8(int *a, int *b) __attribute__((nonnull))
+__attribute__((nonnull(1))) {}
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