Split rsloaderCreateExec into 2 functions.

In some scenerio, such as cross-compilation, we have to
load the ELF object file but not relocate them.  Thus,
we are going to provide 2 functions:

  1. rsloaderLoadExecutable
  2. rsloaderRelocateExecutable

So that we can load the executable WITHOUT relocation.

The behavior of rsloaderCreateExec is remained unchanged
in this commit, though rsloaderCreateExec will become
the composition of these 2 functions.

Change-Id: Idb64aa77ac53161aa95879ccad8f46ce56c1d993

2 files changed, 36 insertions, 12 deletions

diff --git a/android/librsloader.cpp b/android/librsloader.cpp
index 1af18f7..e0004f2 100644
--- a/android/librsloader.cpp
+++ b/android/librsloader.cpp
@@ -36,12 +36,25 @@ static inline ELFObject<32> *unwrap(RSExecRef object) {
   return reinterpret_cast<ELFObject<32> *>(object);
 }
 
-extern "C" RSExecRef
-rsloaderCreateExec(unsigned char const *buf,
-                   size_t buf_size,
-                   void *(*find_symbol)(void *, char const *),
-                   void *find_symbol_context) {
+extern "C" RSExecRef rsloaderCreateExec(unsigned char const *buf,
+                                        size_t buf_size,
+                                        RSFindSymbolFn find_symbol,
+                                        void *find_symbol_context) {
+  RSExecRef object = rsloaderLoadExecutable(buf, buf_size);
+  if (!object) {
+    return NULL;
+  }
+
+  if (!rsloaderRelocateExecutable(object, find_symbol, find_symbol_context)) {
+    rsloaderDisposeExec(object);
+    return NULL;
+  }
+
+  return object;
+}
 
+extern "C" RSExecRef rsloaderLoadExecutable(unsigned char const *buf,
+                                            size_t buf_size) {
   ArchiveReaderLE AR(buf, buf_size);
 
   llvm::OwningPtr<ELFObject<32> > object(ELFObject<32>::read(AR));
@@ -50,15 +63,18 @@ rsloaderCreateExec(unsigned char const *buf,
     return NULL;
   }
 
-  //object->print();
-  object->relocate(find_symbol, find_symbol_context);
-  if (object->getMissingSymbols()) {
-    return NULL;
-  }
-
   return wrap(object.take());
 }
 
+extern "C" int rsloaderRelocateExecutable(RSExecRef object_,
+                                          RSFindSymbolFn find_symbol,
+                                          void *find_symbol_context) {
+  ELFObject<32>* object = unwrap(object_);
+
+  object->relocate(find_symbol, find_symbol_context);
+  return (object->getMissingSymbols() == 0);
+}
+
 extern "C" void rsloaderUpdateSectionHeaders(RSExecRef object_,
                                              unsigned char *buf) {
   ELFObject<32> *object = unwrap(object_);
diff --git a/android/librsloader.h b/android/librsloader.h
index e12fe63..ab8361a 100644
--- a/android/librsloader.h
+++ b/android/librsloader.h
@@ -25,12 +25,20 @@ extern "C" {
 
 struct RSExecOpaque;
 typedef struct RSExecOpaque *RSExecRef;
+typedef void *(*RSFindSymbolFn)(void *, char const *);
 
 RSExecRef rsloaderCreateExec(unsigned char const *buf,
                              size_t buf_size,
-                             void *(*find_symbol)(void *, char const *),
+                             RSFindSymbolFn find_symbol,
                              void *find_symbol_context);
 
+RSExecRef rsloaderLoadExecutable(unsigned char const *buf,
+                                 size_t buf_size);
+
+int rsloaderRelocateExecutable(RSExecRef object,
+                               RSFindSymbolFn find_symbol,
+                               void *find_symbol_context);
+
 void rsloaderUpdateSectionHeaders(RSExecRef object, unsigned char *buf);
 
 void rsloaderDisposeExec(RSExecRef object);