Factor out name-mangling from X86/Printer, which is derived from CWriter,

into this new support class.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7300 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/Mangler.cpp

@@ -0,0 +1,83 @@
+//===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===//
+//
+// Unified name mangler for CWriter and assembly backends.
+//
+//===----------------------------------------------------------------------===//
+
+#include <iostream>
+#include <set>
+#include <string>
+#include "llvm/Value.h"
+#include "llvm/Module.h"
+#include "llvm/Type.h"
+#include "Support/StringExtras.h"
+#include "llvm/Support/Mangler.h"
+
+/// makeNameProper - We don't want identifier names with ., space, or
+/// - in them, so we mangle these characters into the strings "d_",
+/// "s_", and "D_", respectively.
+/// 
+std::string Mangler::makeNameProper(std::string x) {
+  std::string tmp;
+  for (std::string::iterator sI = x.begin(), sEnd = x.end(); sI != sEnd; sI++)
+    switch (*sI) {
+    case '.': tmp += "d_"; break;
+    case ' ': tmp += "s_"; break;
+    case '-': tmp += "D_"; break;
+    default:  tmp += *sI;
+    }
+  return tmp;
+}
+
+std::string Mangler::getValueName(const Value *V) {
+  // Check to see whether we've already named V.
+  ValueMap::iterator VI = Memo.find(V);
+  if (VI != Memo.end()) {
+    return VI->second; // Return the old name for V.
+  }
+
+  std::string name;
+  if (V->hasName()) { // Print out the label if it exists...
+    // Name mangling occurs as follows:
+    // - If V is not a global, mangling always occurs.
+    // - Otherwise, mangling occurs when any of the following are true:
+    //   1) V has internal linkage
+    //   2) V's name would collide if it is not mangled.
+    //
+    const GlobalValue* gv = dyn_cast<GlobalValue>(V);
+    if(gv && !gv->hasInternalLinkage() && !MangledGlobals.count(gv)) {
+      name = makeNameProper(gv->getName());
+    } else {
+      // Non-global, or global with internal linkage / colliding name
+      // -> mangle.
+      name = "l" + utostr(V->getType()->getUniqueID()) + "_" +
+        makeNameProper(V->getName());      
+    }
+  } else {
+    name = "ltmp_" + itostr(Count++) + "_"
+      + utostr(V->getType()->getUniqueID());
+  }
+  Memo[V] = name;
+  return name;
+}
+
+Mangler::Mangler(Module &_M) : M(_M)
+{
+  // Calculate which global values have names that will collide when we throw
+  // away type information.
+  std::set<std::string> FoundNames;
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (I->hasName())                      // If the global has a name...
+      if (FoundNames.count(I->getName()))  // And the name is already used
+        MangledGlobals.insert(I);          // Mangle the name
+      else
+        FoundNames.insert(I->getName());   // Otherwise, keep track of name
+
+  for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
+    if (I->hasName())                      // If the global has a name...
+      if (FoundNames.count(I->getName()))  // And the name is already used
+        MangledGlobals.insert(I);          // Mangle the name
+      else
+        FoundNames.insert(I->getName());   // Otherwise, keep track of name
+}
+