PR10210: New method ConstantArray::getAsCString(). Use it in LTO to

avoid getting embedded trailing null bytes in std::strings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133999 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Constants.h b/include/llvm/Constants.h
index ff599512e6f70d89489bb699a81242805993f633..1afbb8a96d936bde5e1ec2f7187827dd963dfbd5 100644 (file)
--- a/include/llvm/Constants.h
+++ b/include/llvm/Constants.h
@@ -387,6 +387,12 @@ public:
   ///
   std::string getAsString() const;
 
+  /// getAsCString - If this array is isCString(), then this method converts the
+  /// array (without the trailing null byte) to an std::string and returns it.
+  /// Otherwise, it asserts out.
+  ///
+  std::string getAsCString() const;
+
   /// isNullValue - Return true if this is the value that would be returned by
   /// getNullValue.  This always returns false because zero arrays are always
   /// created as ConstantAggregateZero objects.

diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 87f2fe624e5923a85ddea1121c2eda37e06d5b79..4e6e64d19283d90e9783c9178b7c2e9dc751e2ca 100644 (file)
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -1011,17 +1011,32 @@ bool ConstantArray::isCString() const {
 }
 
 
-/// getAsString - If the sub-element type of this array is i8
-/// then this method converts the array to an std::string and returns it.
-/// Otherwise, it asserts out.
+/// convertToString - Helper function for getAsString() and getAsCString().
+static std::string convertToString(const User *U, unsigned len)
+{
+  std::string Result;
+  Result.reserve(len);
+  for (unsigned i = 0; i != len; ++i)
+    Result.push_back((char)cast<ConstantInt>(U->getOperand(i))->getZExtValue());
+  return Result;
+}
+
+/// getAsString - If this array is isString(), then this method converts the
+/// array to an std::string and returns it.  Otherwise, it asserts out.
 ///
 std::string ConstantArray::getAsString() const {
   assert(isString() && "Not a string!");
-  std::string Result;
-  Result.reserve(getNumOperands());
-  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
-    Result.push_back((char)cast<ConstantInt>(getOperand(i))->getZExtValue());
-  return Result;
+  return convertToString(this, getNumOperands());
+}
+
+
+/// getAsCString - If this array is isCString(), then this method converts the
+/// array (without the trailing null byte) to an std::string and returns it.
+/// Otherwise, it asserts out.
+///
+std::string ConstantArray::getAsCString() const {
+  assert(isCString() && "Not a string!");
+  return convertToString(this, getNumOperands() - 1);
 }
 
 

diff --git a/tools/lto/LTOModule.cpp b/tools/lto/LTOModule.cpp
index 8f2b1f48406d71ababb64a49ec9c23a1fd4c4b7d..fe8e6cfa0d025edd9b3d989027f891c9ad719c89 100644 (file)
--- a/tools/lto/LTOModule.cpp
+++ b/tools/lto/LTOModule.cpp
@@ -191,7 +191,7 @@ bool LTOModule::objcClassNameFromExpression(Constant *c, std::string &name) {
       Constant *cn = gvn->getInitializer();
       if (ConstantArray *ca = dyn_cast<ConstantArray>(cn)) {
         if (ca->isCString()) {
-          name = ".objc_class_name_" + ca->getAsString();
+          name = ".objc_class_name_" + ca->getAsCString();
           return true;
         }
       }