New pass to find types in use by a program

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1232 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/IPA/FindUsedTypes.cpp b/lib/Analysis/IPA/FindUsedTypes.cpp
new file mode 100644 (file)
index 0000000..db5a534
--- /dev/null
+++ b/lib/Analysis/IPA/FindUsedTypes.cpp
@@ -0,0 +1,92 @@
+//===- FindUsedTypes.h - Find all Types used by a module --------------------=//
+//
+// This pass is used to seek out all of the types in use by the program.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/FindUsedTypes.h"
+#include "llvm/Assembly/CachedWriter.h"
+#include "llvm/SymbolTable.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/DerivedTypes.h"
+
+// IncorporateType - Incorporate one type and all of its subtypes into the
+// collection of used types.
+//
+void FindUsedTypes::IncorporateType(const Type *Ty) {
+  if (UsedTypes.count(Ty)) return;  // Already contain Ty.
+                             
+  // If ty doesn't already exist in the used types map, add it now.
+  //
+  UsedTypes.insert(Ty);
+  
+  // Make sure to add any types this type references now.
+  //
+  for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
+       I != E; ++I)
+    IncorporateType(*I);
+}
+
+// IncorporateSymbolTable - Add all types referenced by the specified symtab
+// into the collection of used types.
+//
+void FindUsedTypes::IncorporateSymbolTable(const SymbolTable *ST) {
+  assert(0 && "Unimp");
+}
+
+
+// doPassInitialization - This loops over global constants defined in the
+// module, converting them to their new type.
+//
+bool FindUsedTypes::doPassInitialization(Module *m) {
+  const Module *M = m;
+  if (IncludeSymbolTables && M->hasSymbolTable())
+    IncorporateSymbolTable(M->getSymbolTable()); // Add symtab first...
+
+  // Loop over global variables, incorporating their types
+  for (Module::const_giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+    IncorporateType((*I)->getType());
+  return false;
+}
+
+// doPerMethodWork - This incorporates all types used by the specified method
+//
+bool FindUsedTypes::doPerMethodWork(Method *m) {
+  const Method *M = m;
+  if (IncludeSymbolTables && M->hasSymbolTable())
+  IncorporateSymbolTable(M->getSymbolTable()); // Add symtab first...
+  
+  // Loop over all of the instructions in the method, adding their return type
+  // as well as the types of their operands.
+  //
+  for (Method::inst_const_iterator II = M->inst_begin(), IE = M->inst_end();
+       II != IE; ++II) {
+    const Instruction *I = *II;
+    const Type *Ty = I->getType();
+    
+    IncorporateType(Ty);  // Incorporate the type of the instruction
+    for (User::op_const_iterator OI = I->op_begin(), OE = I->op_end();
+         OI != OE; ++OI)
+      if ((*OI)->getType() != Ty)          // Avoid set lookup in common case
+        IncorporateType((*OI)->getType()); // Insert inst operand types as well
+  }
+  
+  return false;
+}
+
+// Print the types found in the module.  If the optional Module parameter is
+// passed in, then the types are printed symbolically if possible, using the
+// symbol table from the module.
+//
+void FindUsedTypes::printTypes(ostream &o, const Module *M = 0) const {
+  o << "Types in use by this module:\n";
+  if (M) {
+    CachedWriter CW(M, o);
+    for (set<const Type *>::const_iterator I = UsedTypes.begin(),
+           E = UsedTypes.end(); I != E; ++I)
+      CW << "  " << *I << endl;
+  } else
+    for (set<const Type *>::const_iterator I = UsedTypes.begin(),
+           E = UsedTypes.end(); I != E; ++I)
+      o << "  " << *I << endl;
+}