MC: Allow modifiers in MCSymbolRefExpr, and eliminate X86MCTargetExpr.
- Although it would be nice to allow this decoupling, the assembler needs to be able to reason about MCSymbolRefExprs in too many places to make this viable. We can use a target specific encoding of the variant if this becomes an issue.
- This patch also extends llvm-mc to support parsing of the modifiers, as opposed to lumping them in with the symbol.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98592 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index 3bd6b1b..a2ed20b 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -8,6 +8,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCExpr.h"
+#include "llvm/ADT/StringSwitch.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
@@ -27,7 +28,8 @@
return;
case MCExpr::SymbolRef: {
- const MCSymbol &Sym = cast<MCSymbolRefExpr>(*this).getSymbol();
+ const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
+ const MCSymbol &Sym = SRE.getSymbol();
// Parenthesize names that start with $ so that they don't look like
// absolute names.
@@ -35,6 +37,10 @@
OS << '(' << Sym << ')';
else
OS << Sym;
+
+ if (SRE.getKind() != MCSymbolRefExpr::VK_None)
+ OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
+
return;
}
@@ -127,20 +133,60 @@
return new (Ctx) MCConstantExpr(Value);
}
+/* *** */
+
const MCSymbolRefExpr *MCSymbolRefExpr::Create(const MCSymbol *Sym,
+ VariantKind Kind,
MCContext &Ctx) {
- return new (Ctx) MCSymbolRefExpr(Sym);
+ return new (Ctx) MCSymbolRefExpr(Sym, Kind);
}
-const MCSymbolRefExpr *MCSymbolRefExpr::Create(StringRef Name, MCContext &Ctx) {
- return Create(Ctx.GetOrCreateSymbol(Name), Ctx);
+const MCSymbolRefExpr *MCSymbolRefExpr::Create(StringRef Name, VariantKind Kind,
+ MCContext &Ctx) {
+ return Create(Ctx.GetOrCreateSymbol(Name), Kind, Ctx);
}
const MCSymbolRefExpr *MCSymbolRefExpr::CreateTemp(StringRef Name,
+ VariantKind Kind,
MCContext &Ctx) {
- return Create(Ctx.GetOrCreateTemporarySymbol(Name), Ctx);
+ return Create(Ctx.GetOrCreateTemporarySymbol(Name), Kind, Ctx);
}
+StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
+ switch (Kind) {
+ default:
+ case VK_Invalid: return "<<invalid>>";
+ case VK_None: return "<<none>>";
+
+ case VK_GOT: return "GOT";
+ case VK_GOTOFF: return "GOTOFF";
+ case VK_GOTPCREL: return "GOTPCREL";
+ case VK_GOTTPOFF: return "GOTTPOFF";
+ case VK_INDNTPOFF: return "INDNTPOFF";
+ case VK_NTPOFF: return "NTPOFF";
+ case VK_PLT: return "PLT";
+ case VK_TLSGD: return "TLSGD";
+ case VK_TPOFF: return "TPOFF";
+ }
+}
+
+MCSymbolRefExpr::VariantKind
+MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
+ return StringSwitch<VariantKind>(Name)
+ .Case("GOT", VK_GOT)
+ .Case("GOTOFF", VK_GOTOFF)
+ .Case("GOTPCREL", VK_GOTPCREL)
+ .Case("GOTTPOFF", VK_GOTTPOFF)
+ .Case("INDNTPOFF", VK_INDNTPOFF)
+ .Case("NTPOFF", VK_NTPOFF)
+ .Case("PLT", VK_PLT)
+ .Case("TLSGD", VK_TLSGD)
+ .Case("TPOFF", VK_TPOFF)
+ .Default(VK_Invalid);
+}
+
+/* *** */
+
void MCTargetExpr::Anchor() {}
/* *** */
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index a241106..4ec5247 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -262,19 +262,29 @@
case AsmToken::String:
case AsmToken::Identifier: {
// This is a symbol reference.
- MCSymbol *Sym = CreateSymbol(getTok().getIdentifier());
+ std::pair<StringRef, StringRef> Split = getTok().getIdentifier().split('@');
+ MCSymbol *Sym = CreateSymbol(Split.first);
+
+ // Lookup the symbol variant if used.
+ MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+ if (Split.first.size() != getTok().getIdentifier().size())
+ Variant = MCSymbolRefExpr::getVariantKindForName(Split.second);
+
EndLoc = Lexer.getLoc();
Lex(); // Eat identifier.
// If this is an absolute variable reference, substitute it now to preserve
// semantics in the face of reassignment.
if (Sym->getValue() && isa<MCConstantExpr>(Sym->getValue())) {
+ if (Variant)
+ return Error(EndLoc, "unexpected modified on variable reference");
+
Res = Sym->getValue();
return false;
}
// Otherwise create a symbol ref.
- Res = MCSymbolRefExpr::Create(Sym, getContext());
+ Res = MCSymbolRefExpr::Create(Sym, Variant, getContext());
return false;
}
case AsmToken::Integer: