Initial checkin of new "Internalize" pass for GCCLD

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2362 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 53 insertions, 0 deletions

diff --git a/include/llvm/Transforms/IPO/Internalize.h b/include/llvm/Transforms/IPO/Internalize.h
new file mode 100644
index 0000000000..e512dfc328
--- /dev/null
+++ b/include/llvm/Transforms/IPO/Internalize.h
@@ -0,0 +1,15 @@
+//===-- Transforms/IPO/Internalize.h - Mark functions internal ---*- C++ -*--=//
+//
+// This pass loops over all of the functions in the input module, looking for a
+// main function.  If a main function is found, all other functions are marked
+// as internal.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORM_IPO_INTERNALIZE_H
+#define LLVM_TRANSFORM_IPO_INTERNALIZE_H
+
+class Pass;
+Pass *createInternalizePass();
+
+#endif
diff --git a/lib/Transforms/IPO/Internalize.cpp b/lib/Transforms/IPO/Internalize.cpp
new file mode 100644
index 0000000000..aadde7c92c
--- /dev/null
+++ b/lib/Transforms/IPO/Internalize.cpp
@@ -0,0 +1,38 @@
+//===-- Internalize.cpp - Mark functions internal -------------------------===//
+//
+// This pass loops over all of the functions in the input module, looking for a
+// main function.  If a main function is found, all other functions are marked
+// as internal.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO/Internalize.h"
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Function.h"
+
+class InternalizePass : public Pass {
+  virtual bool run(Module *M) {
+    bool FoundMain = false;   // Look for a function named main...
+    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+      if ((*I)->getName() == "main") {
+        FoundMain = true;
+        break;
+      }
+    
+    if (!FoundMain) return false;  // No main found, must be a library...
+
+    bool Changed = false;
+
+    // Found a main function, mark all functions not named main as internal.
+    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+      if ((*I)->getName() != "main")  // Leave the main function external
+        (*I)->setInternalLinkage(Changed = true);
+
+    return Changed;
+  }
+};
+
+Pass *createInternalizePass() {
+  return new InternalizePass();
+}