[llvm-commits] [PATCH] [ARM] simplify memory management for ConstantPoolValue

[Saleem Abdulrasool]

Hi bkramer,

Use a std::string rather than a dynamically allocated char* buffer.  This
affords us to use std::string's allocation routines and use the destructor for
the memory management.  Switching to that also means that we can use
operator==(const std::string&, const char *) to perform the string comparison
rather than resorting to libc functionality (i.e. strcmp).


http://llvm-reviews.chandlerc.com/D230

Files:
  lib/Target/ARM/ARMConstantPoolValue.cpp
  lib/Target/ARM/ARMConstantPoolValue.h

Index: lib/Target/ARM/ARMConstantPoolValue.cpp
===================================================================
--- lib/Target/ARM/ARMConstantPoolValue.cpp
+++ lib/Target/ARM/ARMConstantPoolValue.cpp
@@ -206,11 +206,7 @@
                                              bool AddCurrentAddress)
   : ARMConstantPoolValue(C, id, ARMCP::CPExtSymbol, PCAdj, Modifier,
                          AddCurrentAddress),
-    S(strdup(s)) {}
-
-ARMConstantPoolSymbol::~ARMConstantPoolSymbol() {
-  free(const_cast<void*>(reinterpret_cast<const void *>(S)));
-}
+    S(s) {}
 
 ARMConstantPoolSymbol *
 ARMConstantPoolSymbol::Create(LLVMContext &C, const char *s,
@@ -218,14 +214,6 @@
   return new ARMConstantPoolSymbol(C, s, ID, PCAdj, ARMCP::no_modifier, false);
 }
 
-static bool CPV_streq(const char *S1, const char *S2) {
-  if (S1 == S2)
-    return true;
-  if (S1 && S2 && strcmp(S1, S2) == 0)
-    return true;
-  return false;
-}
-
 int ARMConstantPoolSymbol::getExistingMachineCPValue(MachineConstantPool *CP,
                                                      unsigned Alignment) {
   unsigned AlignMask = Alignment - 1;
@@ -238,7 +226,7 @@
       ARMConstantPoolSymbol *APS = dyn_cast<ARMConstantPoolSymbol>(CPV);
       if (!APS) continue;
 
-      if (CPV_streq(APS->S, S) && equals(APS))
+      if (APS->S == S && equals(APS))
         return i;
     }
   }
@@ -248,12 +236,11 @@
 
 bool ARMConstantPoolSymbol::hasSameValue(ARMConstantPoolValue *ACPV) {
   const ARMConstantPoolSymbol *ACPS = dyn_cast<ARMConstantPoolSymbol>(ACPV);
-  return ACPS && CPV_streq(ACPS->S, S) &&
-    ARMConstantPoolValue::hasSameValue(ACPV);
+  return ACPS && ACPS->S == S && ARMConstantPoolValue::hasSameValue(ACPV);
 }
 
 void ARMConstantPoolSymbol::addSelectionDAGCSEId(FoldingSetNodeID &ID) {
-  ID.AddPointer(S);
+  ID.AddPointer(S.c_str());
   ARMConstantPoolValue::addSelectionDAGCSEId(ID);
 }
 
Index: lib/Target/ARM/ARMConstantPoolValue.h
===================================================================
--- lib/Target/ARM/ARMConstantPoolValue.h
+++ lib/Target/ARM/ARMConstantPoolValue.h
@@ -161,19 +161,17 @@
 /// ARMConstantPoolSymbol - ARM-specific constantpool values for external
 /// symbols.
 class ARMConstantPoolSymbol : public ARMConstantPoolValue {
-  const char *S;                // ExtSymbol being loaded.
+  const std::string S;          // ExtSymbol being loaded.
 
   ARMConstantPoolSymbol(LLVMContext &C, const char *s, unsigned id,
                         unsigned char PCAdj, ARMCP::ARMCPModifier Modifier,
                         bool AddCurrentAddress);
 
 public:
-  ~ARMConstantPoolSymbol();
-
   static ARMConstantPoolSymbol *Create(LLVMContext &C, const char *s,
                                        unsigned ID, unsigned char PCAdj);
 
-  const char *getSymbol() const { return S; }
+  const char *getSymbol() const { return S.c_str(); }
 
   virtual int getExistingMachineCPValue(MachineConstantPool *CP,
                                         unsigned Alignment);
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