[mips] Improve error/warning messages and testing for the .cpload assembler directive.

[tomatabacu]

Summary

Improved warning message when using .cpload inside a reorder section and added an error message for using .cpload with Mips16 enabled.
Modified the tests to fit with the changes mentioned above, added a test-case for the N32 ABI in cpload.s and did some reformatting to make the tests easier to read.

[tomatabacu]

For the .cpload in Mips16 case, we have a choice between an error and a warning. I took the more conservative GAS approach and chose the error.

[tomatabacu]

Added an error and test case for when the EndOfStatement is not found at the appropriate location.
Slightly improved the reporting of the ".cpload is not supported in Mips16 mode" error.

[dsanders]

Could you correct the N32 test case?

test/MC/Mips/cpload.s

7–14

N32 is not allowed on a 32-bit processor since it's a 64-bit ABI. You should take the N64 run line and change it to N32 instead.

[tomatabacu]

Fixed the N32 test case.

[dsanders]

Thanks. LGTM

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

bool MipsAsmParser::eatComma(StringRef ErrorStr) {
   }
 
   Parser.Lex(); // Eat the comma.
   return true;
 }
 
 bool MipsAsmParser::parseDirectiveCpLoad(SMLoc Loc) {
   if (AssemblerOptions.back()->isReorder())
-    Warning(Loc, ".cpload in reorder section");
+    Warning(Loc, ".cpload should be inside a noreorder section");
 
-  // FIXME: Warn if cpload is used in Mips16 mode.
+  if (inMips16Mode()) {
+    reportParseError(".cpload is not supported in Mips16 mode");
+    return false;
+  }
 
   SmallVector<std::unique_ptr<MCParsedAsmOperand>, 1> Reg;
   OperandMatchResultTy ResTy = parseAnyRegister(Reg);
   if (ResTy == MatchOperand_NoMatch || ResTy == MatchOperand_ParseFail) {
     reportParseError("expected register containing function address");
     return false;
   }
 
   MipsOperand &RegOpnd = static_cast<MipsOperand &>(*Reg[0]);
   if (!RegOpnd.isGPRAsmReg()) {
     reportParseError(RegOpnd.getStartLoc(), "invalid register");
     return false;
   }
 
+  // If this is not the end of the statement, report an error.
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    reportParseError("unexpected token, expected end of statement");
+    return false;
+  }
+
   getTargetStreamer().emitDirectiveCpLoad(RegOpnd.getGPR32Reg());
   return false;
 }
 
 bool MipsAsmParser::parseDirectiveCPSetup() {
   unsigned FuncReg;
   unsigned Save;
   bool SaveIsReg = true;

test/MC/Mips/cpload-bad.s

 # RUN: not llvm-mc %s -arch=mips -mcpu=mips32r2 2>%t1
 # RUN: FileCheck %s < %t1 -check-prefix=ASM
 
         .text
         .option pic2
+        .set noreorder
+        .set mips16
+        .cpload $25
+# ASM: :[[@LINE-1]]:17: error: .cpload is not supported in Mips16 mode
+
+        .set nomips16
         .set reorder
         .cpload $25
-# ASM: :[[@LINE-1]]:9: warning: .cpload in reorder section
+# ASM: :[[@LINE-1]]:9: warning: .cpload should be inside a noreorder section
+
         .set noreorder
         .cpload $32
 # ASM: :[[@LINE-1]]:17: error: invalid register
+
         .cpload $foo
 # ASM: :[[@LINE-1]]:17: error: expected register containing function address
+
         .cpload bar
 # ASM: :[[@LINE-1]]:17: error: expected register containing function address
+
+        .cpload $25 foobar
+# ASM: :[[@LINE-1]]:21: error: unexpected token, expected end of statement

test/MC/Mips/cpload.s

 # RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 | FileCheck %s -check-prefix=ASM
 #
-# RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 -filetype=obj -o -| \
-# RUN: llvm-objdump -d -r -arch=mips - | \
-# RUN: FileCheck %s -check-prefix=OBJ
+# RUN: llvm-mc %s -arch=mips -mcpu=mips32r2 -mattr=+o32 -filetype=obj -o -| \
+# RUN:  llvm-objdump -d -r -arch=mips - | \
+# RUN:    FileCheck %s -check-prefix=OBJ-O32
 
-# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64r2 -filetype=obj -o -| \
-# RUN: llvm-objdump -d -r -arch=mips - | \
-# RUN: FileCheck %s -check-prefix=OBJ64
+# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64r2 -mattr=-n64,+n32 -filetype=obj -o -| \
+# RUN:  llvm-objdump -d -r -arch=mips - | \
+# RUN:    FileCheck %s -check-prefix=OBJ-N32
+
+# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64r2 -mattr=+n64 -filetype=obj -o -| \
+# RUN:  llvm-objdump -d -r -arch=mips - | \
+# RUN:    FileCheck %s -check-prefix=OBJ-N64
 
 # ASM:    .text
 # ASM:    .option pic2
 # ASM:    .set noreorder
 # ASM:    .cpload $25
 # ASM:    .set reorder
 
-# OBJ:    .text
-# OBJ:    lui $gp, 0
-# OBJ: R_MIPS_HI16 _gp_disp
-# OBJ:    addiu $gp, $gp, 0
-# OBJ: R_MIPS_LO16 _gp_disp
-# OBJ:    addu $gp, $gp, $25
-
-# OBJ64: .text
-# OBJ64-NOT: lui $gp, 0
-# OBJ64-NOT: addiu $gp, $gp, 0
-# OBJ64-NOT: addu $gp, $gp, $25
+# OBJ-O32:    .text
+# OBJ-O32:    lui $gp, 0
+# OBJ-O32: R_MIPS_HI16 _gp_disp
+# OBJ-O32:    addiu $gp, $gp, 0
+# OBJ-O32: R_MIPS_LO16 _gp_disp
+# OBJ-O32:    addu $gp, $gp, $25
+
+# OBJ-N32:     .text
+# OBJ-N32-NOT: lui   $gp, 0
+# OBJ-N32-NOT: addiu $gp, $gp, 0
+# OBJ-N32-NOT: addu  $gp, $gp, $25
+
+# OBJ-N64:     .text
+# OBJ-N64-NOT: lui   $gp, 0
+# OBJ-N64-NOT: addiu $gp, $gp, 0
+# OBJ-N64-NOT: addu  $gp, $gp, $25
 
         .text
         .option pic2
         .set noreorder
         .cpload $25
         .set reorder