Store the backing buffer in Binary

Author: CodaFi

Sources/LLVM/ObjectFile.swift

@@ -15,6 +15,9 @@ public enum BinaryFileError: Error {
 public class BinaryFile {
   let llvm: LLVMBinaryRef
 
+  /// The backing buffer for this binary file.
+  public let buffer: MemoryBuffer
+
   /// The kind of this binary file.
   public let kind: Kind
 
@@ -77,9 +80,10 @@ public class BinaryFile {
     }
   }
 
-  init(llvm: LLVMBinaryRef) {
+  init(llvm: LLVMBinaryRef, buffer: MemoryBuffer) {
     self.llvm = llvm
     self.kind = Kind(llvm: LLVMBinaryGetType(llvm))
+    self.buffer = buffer
   }
 
   /// Creates a Binary File with the contents of a provided memory buffer.
@@ -96,6 +100,7 @@ public class BinaryFile {
       throw BinaryFileError.couldNotCreate(String(cString: error))
     }
     self.kind = Kind(llvm: LLVMBinaryGetType(self.llvm))
+    self.buffer = memoryBuffer
   }
 
   /// Creates an `ObjectFile` with the contents of the object file at
@@ -117,8 +122,8 @@ public class BinaryFile {
 
 /// An in-memory representation of a format-independent object file.
 public final class ObjectFile: BinaryFile {
-  override init(llvm: LLVMBinaryRef) {
-    super.init(llvm: llvm)
+  override init(llvm: LLVMBinaryRef, buffer: MemoryBuffer) {
+    super.init(llvm: llvm, buffer: buffer)
     precondition(self.kind != .machOUniversalBinary,
                  "File format is not an object file; use MachOUniversalBinaryFile instead")
   }
@@ -175,7 +180,8 @@ public final class MachOUniversalBinaryFile: BinaryFile {
       defer { LLVMDisposeMessage(error) }
       throw BinaryFileError.couldNotCreate(String(cString: error))
     }
-    return ObjectFile(llvm: archFile)
+    let buffer = MemoryBuffer(llvm: LLVMBinaryGetMemoryBuffer(archFile))
+    return ObjectFile(llvm: archFile, buffer: buffer)
   }
 }
 

Sources/llvmshims/include/shim.h

@@ -58,6 +58,7 @@ typedef struct LLVMOpaqueBinary *LLVMBinaryRef;
 
 LLVMBinaryType LLVMBinaryGetType(LLVMBinaryRef BR);
 LLVMBinaryRef LLVMCreateBinary(LLVMMemoryBufferRef MemBuf, LLVMContextRef Context, char **ErrorMessage);
+LLVMMemoryBufferRef LLVMBinaryGetMemoryBuffer(LLVMBinaryRef BR);
 void LLVMDisposeBinary(LLVMBinaryRef BR);
 
 LLVMBinaryRef LLVMUniversalBinaryCopyObjectForArchitecture(LLVMBinaryRef BR, const char *Arch, size_t ArchLen, char **ErrorMessage);

Sources/llvmshims/src/shim.cpp

@@ -61,6 +61,7 @@ extern "C" {
 
   LLVMBinaryType LLVMBinaryGetType(LLVMBinaryRef BR);
   LLVMBinaryRef LLVMCreateBinary(LLVMMemoryBufferRef MemBuf, LLVMContextRef Context, char **ErrorMessage);
+  LLVMMemoryBufferRef LLVMBinaryGetMemoryBuffer(LLVMBinaryRef BR);
   void LLVMDisposeBinary(LLVMBinaryRef BR);
 
   LLVMBinaryRef LLVMUniversalBinaryCopyObjectForArchitecture(LLVMBinaryRef BR, const char *Arch, size_t ArchLen, char **ErrorMessage);
@@ -156,6 +157,13 @@ LLVMBinaryRef LLVMCreateBinary(LLVMMemoryBufferRef MemBuf, LLVMContextRef Contex
   return wrap(ObjOrErr.get().release());
 }
 
+LLVMMemoryBufferRef LLVMBinaryGetMemoryBuffer(LLVMBinaryRef BR) {
+  auto Buf = unwrap(BR)->getMemoryBufferRef();
+  return wrap(llvm::MemoryBuffer::getMemBuffer(
+                Buf.getBuffer(), Buf.getBufferIdentifier(),
+                /*RequiresNullTerminator*/false).release());
+}
+
 void LLVMDisposeBinary(LLVMBinaryRef BR) {
   delete unwrap(BR);
 }