From 147dcd8c33258f0239baf9a02bfca846557e09f4 Mon Sep 17 00:00:00 2001
From: Nuno Lopes <nunoplopes@sapo.pt>
Date: Fri, 25 May 2012 17:04:42 +0000
Subject: [PATCH] add CodeGen support for the alloc_size attribute

llvm-svn: 157483
---
 clang/lib/CodeGen/CGCall.cpp    | 17 +++++++++++++++++
 clang/test/CodeGen/alloc_size.c | 11 +++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 clang/test/CodeGen/alloc_size.c

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 3ad1df1..650fe8b 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2087,6 +2087,23 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   CS.setAttributes(Attrs);
   CS.setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
 
+  // add metadata for __attribute__((alloc_size(foo)))
+  if (TargetDecl) {
+    if (const AllocSizeAttr* Attr = TargetDecl->getAttr<AllocSizeAttr>()) {
+      std::vector<llvm::Value*> Args;
+      llvm::IntegerType *Ty = llvm::IntegerType::getInt32Ty(getLLVMContext());
+      bool isMethod = isa<CXXMethodDecl>(TargetDecl);
+
+      for (AllocSizeAttr::args_iterator I = Attr->args_begin(),
+           E = Attr->args_end(); I != E; ++I) {
+        Args.push_back(llvm::ConstantInt::get(Ty, *I + isMethod));
+      }
+
+      llvm::MDNode *MD = llvm::MDNode::get(getLLVMContext(), Args);
+      CS.getInstruction()->setMetadata("alloc_size", MD);
+    }
+  }
+
   // In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC
   // optimizer it can aggressively ignore unwind edges.
   if (CGM.getLangOpts().ObjCAutoRefCount)
diff --git a/clang/test/CodeGen/alloc_size.c b/clang/test/CodeGen/alloc_size.c
new file mode 100644
index 0000000..05aa845
--- /dev/null
+++ b/clang/test/CodeGen/alloc_size.c
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
+
+void *my_recalloc(void *, unsigned, unsigned) __attribute__((alloc_size(2,3))); 
+
+// CHECK: @f
+void* f() {
+  // CHECK: call i8* @my_recalloc{{.*}}, !alloc_size !0
+  return my_recalloc(0, 11, 27);
+}
+
+// CHECK: !0 = metadata !{i32 1, i32 2}
-- 
2.7.4