Merging r315310:

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r315310 | sdardis | 2017-10-10 06:34:45 -0700 (Tue, 10 Oct 2017) | 22 lines

[mips] Partially fix PR34391

Previously, the parsing of the 'subu $reg, ($reg,) imm' relied on a parser
which also rendered the operand to the instruction. In some cases the
general parser could construct an MCExpr which was not a MCConstantExpr
which MipsAsmParser was expecting.

Address this by altering the special handling to cope with unexpected inputs
and fine-tune the handling of cases where an register name that is not
available in the current ABI is regarded as not a match for the custom parser
but also not as an outright error.

Also enforces the binutils restriction that only constants are accepted.

This partially resolves PR34391.

Thanks to Ed Maste for reporting the issue!

Reviewers: nitesh.jain, arichardson

Differential Revision: https://reviews.llvm.org/D37476

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llvm-svn: 318192

3 files changed, 84 insertions, 4 deletions

diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index e12188e70602..f75d23fe6a92 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -5793,14 +5793,21 @@ OperandMatchResultTy
 MipsAsmParser::parseInvNum(OperandVector &Operands) {
   MCAsmParser &Parser = getParser();
   const MCExpr *IdVal;
-  // If the first token is '$' we may have register operand.
-  if (Parser.getTok().is(AsmToken::Dollar))
-    return MatchOperand_NoMatch;
+  // If the first token is '$' we may have register operand. We have to reject
+  // cases where it is not a register. Complicating the matter is that
+  // register names are not reserved across all ABIs.
+  // Peek past the dollar to see if it's a register name for this ABI.
   SMLoc S = Parser.getTok().getLoc();
+  if (Parser.getTok().is(AsmToken::Dollar)) {
+    return matchCPURegisterName(Parser.getLexer().peekTok().getString()) == -1
+               ? MatchOperand_ParseFail
+               : MatchOperand_NoMatch;
+  }
   if (getParser().parseExpression(IdVal))
     return MatchOperand_ParseFail;
   const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(IdVal);
-  assert(MCE && "Unexpected MCExpr type.");
+  if (!MCE)
+    return MatchOperand_NoMatch;
   int64_t Val = MCE->getValue();
   SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
   Operands.push_back(MipsOperand::CreateImm(
diff --git a/llvm/test/MC/Mips/macro-aliases-invalid-wrong-error.s b/llvm/test/MC/Mips/macro-aliases-invalid-wrong-error.s
new file mode 100644
index 000000000000..b87646d0b09a
--- /dev/null
+++ b/llvm/test/MC/Mips/macro-aliases-invalid-wrong-error.s
@@ -0,0 +1,38 @@
+# RUN: not llvm-mc -arch=mips %s 2>%t1
+# RUN: FileCheck --check-prefix=O32 %s < %t1
+
+# RUN: not llvm-mc -arch=mips64 %s 2>%t1
+# RUN: FileCheck --check-prefix=N64 %s < %t1
+
+# Check that subu only rejects any non-constant values.
+
+.globl end
+  subu  $4, $4, %lo($start)   # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $4, $start        # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $a4, $a4          # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $4, %hi(end)      # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $4, end + 4       # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $4, end           # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $4, sp            # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+
+  subu  $4, %lo($start)       # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $start            # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, $a4               # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, %hi(end)          # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, end + 4           # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, end               # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+  subu  $4, sp                # O32: [[@LINE]]:{{[0-9]+}}: error: unexpected token in argument list
+                              # N64: [[@LINE-1]]:{{[0-9]+}}: error: unexpected token in argument list
+
+$start:
diff --git a/llvm/test/MC/Mips/macro-aliases.s b/llvm/test/MC/Mips/macro-aliases.s
new file mode 100644
index 000000000000..daa1d8b2437c
--- /dev/null
+++ b/llvm/test/MC/Mips/macro-aliases.s
@@ -0,0 +1,35 @@
+# RUN: llvm-mc -arch=mips -mcpu=mips32r2 %s -show-inst | FileCheck %s
+
+# Test that subu accepts constant operands and inverts them when
+# rendering the operand.
+
+  subu  $4, $4, 4          # CHECK: ADDiu
+                           # CHECK; Imm:-4
+  subu  $gp, $gp, 4        # CHECK: ADDiu
+                           # CHECK; Imm:-4
+  subu  $sp, $sp, 4        # CHECK: ADDiu
+                           # CHECK; Imm:-4
+  subu  $4, $4, -4         # CHECK: ADDiu
+                           # CHECK; Imm:4
+  subu  $gp, $gp, -4       # CHECK: ADDiu
+                           # CHECK; Imm:4
+  subu  $sp, $sp, -4       # CHECK: ADDiu
+                           # CHECK; Imm:4
+  subu  $sp, $sp, -(4 + 4) # CHECK: ADDiu
+                           # CHECK: Imm:8
+
+  subu  $4, 8              # CHECK: ADDiu
+                           # CHECK; Imm:-8
+  subu  $gp, 8             # CHECK: ADDiu
+                           # CHECK; Imm:-8
+  subu  $sp, 8             # CHECK: ADDiu
+                           # CHECK; Imm:-8
+  subu  $4, -8             # CHECK: ADDiu
+                           # CHECK; Imm:8
+  subu  $gp, -8            # CHECK: ADDiu
+                           # CHECK; Imm:8
+  subu  $sp, -8            # CHECK: ADDiu
+                           # CHECK; Imm:8
+  subu  $sp, -(4 + 4)      # CHECK: ADDiu
+                           # CHECK: Imm:8
+