From 7c3600de949347bf5ea6369b2546fac15bd96415 Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Fri, 16 Oct 2009 01:33:57 +0000
Subject: [PATCH] MC: Move assembler variable values from MCContext to
 MCSymbol.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84229 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/MC/MCContext.h | 27 ---------------------------
 include/llvm/MC/MCSymbol.h  | 31 ++++++++++++++++++++++++++++---
 lib/MC/MCExpr.cpp           |  7 +++++--
 3 files changed, 33 insertions(+), 32 deletions(-)

diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h
index d5c24043891..e577ef53d13 100644
--- a/include/llvm/MC/MCContext.h
+++ b/include/llvm/MC/MCContext.h
@@ -33,11 +33,6 @@ namespace llvm {
     /// Symbols - Bindings of names to symbols.
     StringMap<MCSymbol*> Symbols;
 
-    /// SymbolValues - Bindings of symbols to values.
-    //
-    // FIXME: Is there a good reason to not just put this in the MCSymbol?
-    DenseMap<const MCSymbol*, const MCExpr*> SymbolValues;
-
     /// Allocator - Allocator object used for creating machine code objects.
     ///
     /// We use a bump pointer allocator to avoid the need to track all allocated
@@ -75,28 +70,6 @@ namespace llvm {
     /// LookupSymbol - Get the symbol for @param Name, or null.
     MCSymbol *LookupSymbol(const StringRef &Name) const;
 
-    /// @}
-    /// @name Symbol Value Table
-    /// @{
-
-    /// ClearSymbolValue - Erase the variable binding for @arg Symbol, if one
-    /// exists.
-    void ClearSymbolValue(const MCSymbol *Symbol) {
-      SymbolValues.erase(Symbol);
-    }
-
-    /// SetSymbolValue - Set the variable binding for @arg Symbol to @arg Value.
-    void SetSymbolValue(const MCSymbol *Symbol, const MCExpr *Value) {
-      assert(Value && "Invalid variable assignment!");
-      SymbolValues.insert(std::make_pair(Symbol, Value));
-    }
-
-    /// GetSymbolValue - Return the current variable value for @arg Symbol, or
-    /// null if @arg Symbol is not a variable.
-    const MCExpr *GetSymbolValue(const MCSymbol *Symbol) const {
-      return SymbolValues.lookup(Symbol);
-    }
-
     /// @}
 
     void *Allocate(unsigned Size, unsigned Align = 8) {
diff --git a/include/llvm/MC/MCSymbol.h b/include/llvm/MC/MCSymbol.h
index 5dd7d68585c..d08f0e5f8ed 100644
--- a/include/llvm/MC/MCSymbol.h
+++ b/include/llvm/MC/MCSymbol.h
@@ -20,6 +20,7 @@
 
 namespace llvm {
   class MCAsmInfo;
+  class MCExpr;
   class MCSection;
   class MCContext;
   class raw_ostream;
@@ -45,6 +46,9 @@ namespace llvm {
     /// absolute symbols.
     const MCSection *Section;
 
+    /// Value - If non-null, the value for a variable symbol.
+    const MCExpr *Value;
+
     /// IsTemporary - True if this is an assembler temporary label, which
     /// typically does not survive in the .o file's symbol table.  Usually
     /// "Lfoo" or ".foo".
@@ -52,9 +56,9 @@ namespace llvm {
 
   private:  // MCContext creates and uniques these.
     friend class MCContext;
-    MCSymbol(const StringRef &_Name, bool _IsTemporary) 
-      : Name(_Name), Section(0), IsTemporary(_IsTemporary) {}
-    
+    MCSymbol(const StringRef &_Name, bool _IsTemporary)
+      : Name(_Name), Section(0), Value(0), IsTemporary(_IsTemporary) {}
+
     MCSymbol(const MCSymbol&);       // DO NOT IMPLEMENT
     void operator=(const MCSymbol&); // DO NOT IMPLEMENT
   public:
@@ -69,6 +73,10 @@ namespace llvm {
       return IsTemporary;
     }
 
+    /// @}
+    /// @name Associated Sections
+    /// @{
+
     /// isDefined - Check if this symbol is defined (i.e., it has an address).
     ///
     /// Defined symbols are either absolute or in some section.
@@ -104,6 +112,23 @@ namespace llvm {
     /// setAbsolute - Mark the symbol as absolute.
     void setAbsolute() { Section = AbsolutePseudoSection; }
 
+    /// @}
+    /// @name Variable Symbols
+    /// @{
+
+    /// isVariable - Check if this is a variable symbol.
+    bool isVariable() const {
+      return Value != 0;
+    }
+
+    /// getValue() - Get the value for variable symbols, or null if the symbol
+    /// is not a variable.
+    const MCExpr *getValue() const { return Value; }
+
+    void setValue(const MCExpr *Value) {
+      this->Value = Value;
+    }
+
     /// @}
 
     /// print - Print the value to the stream \arg OS.
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index 4c92bbb0a50..d6e545fa78c 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -181,8 +181,11 @@ bool MCExpr::EvaluateAsRelocatable(MCContext &Ctx, MCValue &Res) const {
 
   case SymbolRef: {
     const MCSymbol &Sym = cast<MCSymbolRefExpr>(this)->getSymbol();
-    if (const MCExpr *Value = Ctx.GetSymbolValue(&Sym))
-      return Value->EvaluateAsRelocatable(Ctx, Res);
+
+    // Evaluate recursively if this is a variable.
+    if (Sym.isVariable())
+      return Sym.getValue()->EvaluateAsRelocatable(Ctx, Res);
+
     Res = MCValue::get(&Sym, 0, 0);
     return true;
   }
-- 
2.34.1