[PATCH] D68764: [ARM][AsmParser] handles offset expression in parentheses

[Jian Cai via Phabricator via llvm-commits]

jcai19 created this revision.
Herald added subscribers: llvm-commits, hiraditya, kristof.beyls.
Herald added a project: LLVM.
jcai19 added a reviewer: nickdesaulniers.
jcai19 added subscribers: manojgupta, llozano.

Integrated assembler does not acceet offset expressions surrounded by
parenthesis. Handle this case for GAS compability.
https://bugs.llvm.org/show_bug.cgi?id=43631


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D68764

Files:
  llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
  llvm/test/MC/ARM/gas-compl.s


Index: llvm/test/MC/ARM/gas-compl.s
===================================================================
--- /dev/null
+++ llvm/test/MC/ARM/gas-compl.s
@@ -0,0 +1,8 @@
+@ RUN: llvm-mc -triple=arm < %s | FileCheck %s
+
+@ CHECK: ldr	r12, [sp, #15]
+.syntax unified
+  ldr r12, [sp, #(15)]
+@ CHECK: ldr	r12, [sp, #40]
+.syntax unified
+  ldr r12, [sp, #(15+5*5)]
Index: llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
===================================================================
--- llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5734,19 +5734,24 @@
   }
 
   // If we have a '#', it's an immediate offset, else assume it's a register
-  // offset. Be friendly and also accept a plain integer (without a leading
-  // hash) for gas compatibility.
+  // offset. Be friendly and also accept a plain integer or expression (without
+  // a leading hash) for gas compatibility.
   if (Parser.getTok().is(AsmToken::Hash) ||
       Parser.getTok().is(AsmToken::Dollar) ||
+      Parser.getTok().is(AsmToken::LParen) ||
       Parser.getTok().is(AsmToken::Integer)) {
-    if (Parser.getTok().isNot(AsmToken::Integer))
-      Parser.Lex(); // Eat '#' or '$'.
+    bool StartsWithParen = false;
+    if (Parser.getTok().isNot(AsmToken::Integer)) {
+      StartsWithParen = Parser.getTok().is(AsmToken::LParen);
+      Parser.Lex(); // Eat '#' or '$' or '('
+    }
     E = Parser.getTok().getLoc();
 
     bool isNegative = getParser().getTok().is(AsmToken::Minus);
     const MCExpr *Offset;
-    if (getParser().parseExpression(Offset))
+    if (getParser().parseExpression(Offset)) {
      return true;
+    }
 
     // The expression has to be a constant. Memory references with relocations
     // don't come through here, as they use the <label> forms of the relevant
@@ -5762,6 +5767,10 @@
       CE = MCConstantExpr::create(std::numeric_limits<int32_t>::min(),
                                   getContext());
 
+    // Check if the offset is surrounded by parentheses
+    if (StartsWithParen && Parser.getTok().isNot(AsmToken::RParen))
+      return Error(Parser.getTok().getLoc(), "')' expected");
+
     // Now we should have the closing ']'
     if (Parser.getTok().isNot(AsmToken::RBrac))
       return Error(Parser.getTok().getLoc(), "']' expected");
@@ -6048,6 +6057,8 @@
     S = Parser.getTok().getLoc();
     Parser.Lex();
 
+    llvm::dbgs() << __func__ << Parser.getTok().getString() << "\n";
+
     if (Parser.getTok().isNot(AsmToken::Colon)) {
       bool isNegative = Parser.getTok().is(AsmToken::Minus);
       const MCExpr *ImmVal;


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