Add malloc call utility functions. Patch by Victor Hernandez.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81426 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 86 insertions, 0 deletions

diff --git a/include/llvm/Analysis/MallocHelper.h b/include/llvm/Analysis/MallocHelper.h
new file mode 100644
index 0000000..06959ab
--- /dev/null
+++ b/include/llvm/Analysis/MallocHelper.h
@@ -0,0 +1,86 @@
+//===- llvm/Analysis/MallocHelper.h ---- Identify malloc calls --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This family of functions identifies calls to malloc, bitcasts of malloc
+// calls, and the types and array sizes associated with them.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_MALLOCHELPER_H
+#define LLVM_ANALYSIS_MALLOCHELPER_H
+
+namespace llvm {
+class BitCastInst;
+class CallInst;
+class Instruction;
+class PointerType;
+class Twine;
+class Type;
+class Value;
+
+//===----------------------------------------------------------------------===//
+//  malloc Call Utility Functions.
+//
+
+/// isMalloc - Returns true if the the value is either a malloc call or a
+/// bitcast of the result of a malloc call
+bool isMalloc(const Value* I);
+bool isMalloc(Value* I);
+
+/// extractMallocCall - Returns the corresponding CallInst if the instruction
+/// is a malloc call.  Since CallInst::CreateMalloc() only creates calls, we
+/// ignore InvokeInst here.
+const CallInst* extractMallocCall(const Value* I);
+CallInst* extractMallocCall(Value* I);
+
+/// extractMallocCallFromBitCast - Returns the corresponding CallInst if the
+/// instruction is a bitcast of the result of a malloc call.
+const CallInst* extractMallocCallFromBitCast(const Value* I);
+CallInst* extractMallocCallFromBitCast(Value* I);
+
+/// isArrayMalloc - Returns the corresponding CallInst if the instruction 
+/// matches the malloc call IR generated by CallInst::CreateMalloc().  This 
+/// means that it is a malloc call with one bitcast use AND the malloc call's 
+/// size argument is:
+///  1. a constant not equal to the malloc's allocated type
+/// or
+///  2. the result of a multiplication by the malloc's allocated type
+/// Otherwise it returns NULL.
+/// The unique bitcast is needed to determine the type/size of the array
+/// allocation.
+CallInst* isArrayMalloc(Value* I);
+const CallInst* isArrayMalloc(const Value* I);
+
+/// getMallocType - Returns the PointerType resulting from the malloc call.
+/// This PointerType is the result type of the call's only bitcast use.
+/// If there is no unique bitcast use, then return NULL.
+const PointerType* getMallocType(const CallInst* CI);
+
+/// getMallocAllocatedType - Returns the Type allocated by malloc call. This
+/// Type is the result type of the call's only bitcast use. If there is no
+/// unique bitcast use, then return NULL.
+const Type* getMallocAllocatedType(const CallInst* CI);
+
+/// getMallocArraySize - Returns the array size of a malloc call.  The array
+/// size is computated in 1 of 3 ways:
+///  1. If the element type if of size 1, then array size is the argument to 
+///     malloc.
+///  2. Else if the malloc's argument is a constant, the array size is that
+///     argument divided by the element type's size.
+///  3. Else the malloc argument must be a multiplication and the array size is
+///     the first operand of the multiplication.
+/// This function returns constant 1 if:
+///  1. The malloc call's allocated type cannot be determined.
+///  2. IR wasn't created by a call to CallInst::CreateMalloc() with a non-NULL
+///     ArraySize.
+Value* getMallocArraySize(CallInst* CI);
+
+} // End llvm namespace
+
+#endif