Add, and infer, a nofree function attribute

This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).

Reviewers: jdoerfert

Differential Revision: https://reviews.llvm.org/D49165

llvm-svn: 365336

2 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index a339f6eb710..0ba76f0f371 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1278,6 +1278,8 @@ static uint64_t getRawAttributeMask(Attribute::AttrKind Val) {
     return 1ULL << 61;
   case Attribute::WillReturn:
     return 1ULL << 62;
+  case Attribute::NoFree:
+    return 1ULL << 63;
   case Attribute::Dereferenceable:
     llvm_unreachable("dereferenceable attribute not supported in raw format");
     break;
@@ -1442,6 +1444,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
     return Attribute::NoCapture;
   case bitc::ATTR_KIND_NO_DUPLICATE:
     return Attribute::NoDuplicate;
+  case bitc::ATTR_KIND_NOFREE:
+    return Attribute::NoFree;
   case bitc::ATTR_KIND_NO_IMPLICIT_FLOAT:
     return Attribute::NoImplicitFloat;
   case bitc::ATTR_KIND_NO_INLINE:
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 547889f82c7..65b9e0bb6a1 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -639,6 +639,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
     return bitc::ATTR_KIND_NO_CAPTURE;
   case Attribute::NoDuplicate:
     return bitc::ATTR_KIND_NO_DUPLICATE;
+  case Attribute::NoFree:
+    return bitc::ATTR_KIND_NOFREE;
   case Attribute::NoImplicitFloat:
     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
   case Attribute::NoInline: