Add a MCObjectFormat class so that code common to all targets that use a

single object format can be shared.

This also adds support for

mov zed+(bar-foo), %eax

on ELF and COFF targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116675 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 39 insertions, 27 deletions

diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index e9a6062fe7..3524b8035c 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -14,6 +14,7 @@
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCObjectFormat.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/Debug.h"
@@ -237,7 +238,8 @@ bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout) const {
   return true;
 }
 
-static bool EvaluateSymbolicAdd(const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
+static bool EvaluateSymbolicAdd(const MCAsmLayout *Layout, bool InSet,
+                                const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
                                 const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst,
                                 MCValue &Res) {
   // We can't add or subtract two symbols.
@@ -255,12 +257,40 @@ static bool EvaluateSymbolicAdd(const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
     if (!A)
       return false;
   }
+
+  // Absolutize symbol differences between defined symbols when we have a
+  // layout object and the target requests it.
+
+  if (Layout && A && B) {
+    const MCSymbol &SA = A->getSymbol();
+    const MCSymbol &SB = B->getSymbol();
+    const MCObjectFormat &F =
+      Layout->getAssembler().getBackend().getObjectFormat();
+    if (SA.isDefined() && SB.isDefined() && F.isAbsolute(InSet, SA, SB)) {
+      const MCAssembler &Asm = Layout->getAssembler();
+      MCSymbolData &AD = Asm.getSymbolData(A->getSymbol());
+      MCSymbolData &BD = Asm.getSymbolData(B->getSymbol());
+      Res = MCValue::get(+ Layout->getSymbolAddress(&AD)
+                         - Layout->getSymbolAddress(&BD)
+                         + LHS.getConstant()
+                         + RHS_Cst);
+      return true;
+    }
+  }
+
+
   Res = MCValue::get(A, B, LHS.getConstant() + RHS_Cst);
   return true;
 }
 
 bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
                                    const MCAsmLayout *Layout) const {
+  return EvaluateAsRelocatableImpl(Res, Layout, false);
+}
+
+bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
+                                       const MCAsmLayout *Layout,
+                                       bool InSet) const {
   ++stats::MCExprEvaluate;
 
   switch (getKind()) {
@@ -276,27 +306,9 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
     const MCSymbol &Sym = SRE->getSymbol();
 
     // Evaluate recursively if this is a variable.
-    if (Sym.isVariable()) {
-      if (!Sym.getVariableValue()->EvaluateAsRelocatable(Res, Layout))
-        return false;
-
-      // Absolutize symbol differences between defined symbols when we have a
-      // layout object and the target requests it.
-      if (Layout && Res.getSymB() &&
-          Layout->getAssembler().getBackend().hasAbsolutizedSet() &&
-          Res.getSymA()->getSymbol().isDefined() &&
-          Res.getSymB()->getSymbol().isDefined()) {
-        MCSymbolData &A =
-          Layout->getAssembler().getSymbolData(Res.getSymA()->getSymbol());
-        MCSymbolData &B =
-          Layout->getAssembler().getSymbolData(Res.getSymB()->getSymbol());
-        Res = MCValue::get(+ Layout->getSymbolAddress(&A)
-                           - Layout->getSymbolAddress(&B)
-                           + Res.getConstant());
-      }
-
-      return true;
-    }
+    if (Sym.isVariable())
+      return Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Layout,
+                                                               true);
 
     Res = MCValue::get(SRE, 0, 0);
     return true;
@@ -306,7 +318,7 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
     const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
     MCValue Value;
 
-    if (!AUE->getSubExpr()->EvaluateAsRelocatable(Value, Layout))
+    if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Layout, InSet))
       return false;
 
     switch (AUE->getOpcode()) {
@@ -339,8 +351,8 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
     const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
     MCValue LHSValue, RHSValue;
 
-    if (!ABE->getLHS()->EvaluateAsRelocatable(LHSValue, Layout) ||
-        !ABE->getRHS()->EvaluateAsRelocatable(RHSValue, Layout))
+    if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Layout, InSet) ||
+        !ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Layout, InSet))
       return false;
 
     // We only support a few operations on non-constant expressions, handle
@@ -351,13 +363,13 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
         return false;
       case MCBinaryExpr::Sub:
         // Negate RHS and add.
-        return EvaluateSymbolicAdd(LHSValue,
+        return EvaluateSymbolicAdd(Layout, InSet, LHSValue,
                                    RHSValue.getSymB(), RHSValue.getSymA(),
                                    -RHSValue.getConstant(),
                                    Res);
 
       case MCBinaryExpr::Add:
-        return EvaluateSymbolicAdd(LHSValue,
+        return EvaluateSymbolicAdd(Layout, InSet, LHSValue,
                                    RHSValue.getSymA(), RHSValue.getSymB(),
                                    RHSValue.getConstant(),
                                    Res);