[llvm] r225758 - ARM: prepare prefix parsing for improved AAELF support

[Saleem Abdulrasool]

Author: compnerd
Date: Mon Jan 12 21:22:49 2015
New Revision: 225758

URL: http://llvm.org/viewvc/llvm-project?rev=225758&view=rev
Log:
ARM: prepare prefix parsing for improved AAELF support

AAELF specifies a number of ELF specific relocation types which have custom
prefixes for the symbol reference.  Switch the parser to be more table driven
with an idea of file formats for which they apply.  NFC.

Modified:
    llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp

Modified: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp?rev=225758&r1=225757&r2=225758&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp Mon Jan 12 21:22:49 2015
@@ -5254,15 +5254,52 @@ bool ARMAsmParser::parsePrefix(ARMMCExpr
     return true;
   }
 
+  enum {
+    COFF = (1 << MCObjectFileInfo::IsCOFF),
+    ELF = (1 << MCObjectFileInfo::IsELF),
+    MACHO = (1 << MCObjectFileInfo::IsMachO)
+  };
+  static const struct PrefixEntry {
+    const char *Spelling;
+    ARMMCExpr::VariantKind VariantKind;
+    uint8_t SupportedFormats;
+  } PrefixEntries[] = {
+    { "lower16", ARMMCExpr::VK_ARM_LO16, COFF | ELF | MACHO },
+    { "upper16", ARMMCExpr::VK_ARM_HI16, COFF | ELF | MACHO },
+  };
+
   StringRef IDVal = Parser.getTok().getIdentifier();
-  if (IDVal == "lower16") {
-    RefKind = ARMMCExpr::VK_ARM_LO16;
-  } else if (IDVal == "upper16") {
-    RefKind = ARMMCExpr::VK_ARM_HI16;
-  } else {
+
+  const auto &Prefix =
+      std::find_if(std::begin(PrefixEntries), std::end(PrefixEntries),
+                   [&IDVal](const PrefixEntry &PE) {
+                      return PE.Spelling == IDVal;
+                   });
+  if (Prefix == std::end(PrefixEntries)) {
     Error(Parser.getTok().getLoc(), "unexpected prefix in operand");
     return true;
   }
+
+  uint8_t CurrentFormat;
+  switch (getContext().getObjectFileInfo()->getObjectFileType()) {
+  case MCObjectFileInfo::IsMachO:
+    CurrentFormat = MACHO;
+    break;
+  case MCObjectFileInfo::IsELF:
+    CurrentFormat = ELF;
+    break;
+  case MCObjectFileInfo::IsCOFF:
+    CurrentFormat = COFF;
+    break;
+  }
+
+  if (~Prefix->SupportedFormats & CurrentFormat) {
+    Error(Parser.getTok().getLoc(),
+          "cannot represent relocation in the current file format");
+    return true;
+  }
+
+  RefKind = Prefix->VariantKind;
   Parser.Lex();
 
   if (getLexer().isNot(AsmToken::Colon)) {
@@ -5270,6 +5307,7 @@ bool ARMAsmParser::parsePrefix(ARMMCExpr
     return true;
   }
   Parser.Lex(); // Eat the last ':'
+
   return false;
 }