Given target assembler parsers a chance to handle variant expressions

first. Use this to turn the PPC modifiers into PPC specific expressions,
allowing them to work on constants.

llvm-svn: 189400

llvm/include/llvm/MC/MCTargetAsmParser.h

@@ -11,6 +11,7 @@
 #define LLVM_MC_TARGETPARSER_H
 
 #include "llvm/MC/MCParser/MCAsmParserExtension.h"
+#include "llvm/MC/MCExpr.h"
 
 namespace llvm {
 class MCStreamer;
@@ -174,6 +175,12 @@ public:
 
   virtual void convertToMapAndConstraints(unsigned Kind,
                       const SmallVectorImpl<MCParsedAsmOperand*> &Operands) = 0;
+
+  virtual const MCExpr *applyModifierToExpr(const MCExpr *E,
+                                            MCSymbolRefExpr::VariantKind,
+                                            MCContext &Ctx) {
+    return 0;
+  }
 };
 
 } // End llvm namespace

llvm/lib/MC/MCParser/AsmParser.cpp

@@ -896,6 +896,10 @@ bool AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
 const MCExpr *
 AsmParser::ApplyModifierToExpr(const MCExpr *E,
                                MCSymbolRefExpr::VariantKind Variant) {
+  // Ask the target implementation about this expression first.
+  const MCExpr *NewE = getTargetParser().applyModifierToExpr(E, Variant, Ctx);
+  if (NewE)
+    return NewE;
   // Recurse over the given expression, rebuilding it to apply the given variant
   // if there is exactly one symbol.
   switch (E->getKind()) {

llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp

@@ -235,6 +235,10 @@ public:
   virtual bool ParseDirective(AsmToken DirectiveID);
 
   unsigned validateTargetOperandClass(MCParsedAsmOperand *Op, unsigned Kind);
+
+  virtual const MCExpr *applyModifierToExpr(const MCExpr *E,
+                                            MCSymbolRefExpr::VariantKind,
+                                            MCContext &Ctx);
 };
 
 /// PPCOperand - Instances of this class represent a parsed PowerPC machine
@@ -1363,3 +1367,26 @@ unsigned PPCAsmParser::validateTargetOperandClass(MCParsedAsmOperand *AsmOp,
   return Match_InvalidOperand;
 }
 
+const MCExpr *
+PPCAsmParser::applyModifierToExpr(const MCExpr *E,
+                                  MCSymbolRefExpr::VariantKind Variant,
+                                  MCContext &Ctx) {
+  switch (Variant) {
+  case MCSymbolRefExpr::VK_PPC_LO:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_LO, E, false, Ctx);
+  case MCSymbolRefExpr::VK_PPC_HI:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_HI, E, false, Ctx);
+  case MCSymbolRefExpr::VK_PPC_HA:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_HA, E, false, Ctx);
+  case MCSymbolRefExpr::VK_PPC_HIGHER:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_HIGHER, E, false, Ctx);
+  case MCSymbolRefExpr::VK_PPC_HIGHERA:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_HIGHERA, E, false, Ctx);
+  case MCSymbolRefExpr::VK_PPC_HIGHEST:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_HIGHEST, E, false, Ctx);
+  case MCSymbolRefExpr::VK_PPC_HIGHESTA:
+    return PPCMCExpr::Create(PPCMCExpr::VK_PPC_HIGHESTA, E, false, Ctx);
+  default:
+    return 0;
+  }
+}

llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.cpp

@@ -54,7 +54,7 @@ PPCMCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
                                      const MCAsmLayout *Layout) const {
   MCValue Value;
 
-  if (!getSubExpr()->EvaluateAsRelocatable(Value, *Layout))
+  if (Layout && !getSubExpr()->EvaluateAsRelocatable(Value, *Layout))
     return false;
 
   if (Value.isAbsolute()) {
@@ -85,7 +85,7 @@ PPCMCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
         break;
     }
     Res = MCValue::get(Result);
-  } else {
+  } else if (Layout) {
     MCContext &Context = Layout->getAssembler().getContext();
     const MCSymbolRefExpr *Sym = Value.getSymA();
     MCSymbolRefExpr::VariantKind Modifier = Sym->getKind();
@@ -118,7 +118,8 @@ PPCMCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
     }
     Sym = MCSymbolRefExpr::Create(&Sym->getSymbol(), Modifier, Context);
     Res = MCValue::get(Sym, Value.getSymB(), Value.getConstant());
-  }
+  } else
+    return false;
 
   return true;
 }

llvm/test/MC/PowerPC/ppc64-errors.s

@@ -96,3 +96,6 @@
 # CHECK-NEXT: ld 1, 32768(2)
               ld 1, 32768(2)
 
+# CHECK: error: invalid modifier 'got' (no symbols present)
+         addi 4, 3, 123@got
+# CHECK-NEXT: addi 4, 3, 123@got

llvm/test/MC/PowerPC/ppc64-fixups.s

@@ -442,3 +442,7 @@ base:
 # CHECK-REL: 0x{{[0-9A-F]*[08]}} R_PPC64_DTPREL64 target 0x0
 	.quad target@dtprel
 
+# Constant fixup
+        ori 1, 2, 131071@l
+# CHECK: ori 1, 2, 131071@l              # encoding: [0x60,0x41,A,A]
+# CHECK-NEXT:                            #   fixup A - offset: 2, value: 131071@l, kind: fixup_ppc_half16