[llvm-commits] [llvm] r130524 - in /llvm/trunk: lib/MC/MCAssembler.cpp test/MC/MachO/variable-errors.s

[Daniel Dunbar]

Author: ddunbar
Date: Fri Apr 29 13:20:20 2011
New Revision: 130524

URL: http://llvm.org/viewvc/llvm-project?rev=130524&view=rev
Log:
MCAsmLayout: Add support for computing the symbol offset of variables. Not
currently used, because variables don't get reported as being "defined".

Added:
    llvm/trunk/test/MC/MachO/variable-errors.s
Modified:
    llvm/trunk/lib/MC/MCAssembler.cpp

Modified: llvm/trunk/lib/MC/MCAssembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAssembler.cpp?rev=130524&r1=130523&r2=130524&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAssembler.cpp (original)
+++ llvm/trunk/lib/MC/MCAssembler.cpp Fri Apr 29 13:20:20 2011
@@ -102,6 +102,33 @@
 }
 
 uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const {
+  const MCSymbol &S = SD->getSymbol();
+
+  // If this is a variable, then recursively evaluate now.
+  if (S.isVariable()) {
+    MCValue Target;
+    if (!S.getVariableValue()->EvaluateAsRelocatable(Target, *this))
+      report_fatal_error("unable to evaluate offset for variable '" +
+                         S.getName() + "'");
+
+    // Verify that any used symbols are defined.
+    if (Target.getSymA() && Target.getSymA()->getSymbol().isUndefined())
+      report_fatal_error("unable to evaluate offset to undefined symbol '" +
+                         Target.getSymA()->getSymbol().getName() + "'");
+    if (Target.getSymB() && Target.getSymB()->getSymbol().isUndefined())
+      report_fatal_error("unable to evaluate offset to undefined symbol '" +
+                         Target.getSymB()->getSymbol().getName() + "'");
+      
+    uint64_t Offset = Target.getConstant();
+    if (Target.getSymA())
+      Offset += getSymbolOffset(&Assembler.getSymbolData(
+                                  Target.getSymA()->getSymbol()));
+    if (Target.getSymB())
+      Offset -= getSymbolOffset(&Assembler.getSymbolData(
+                                  Target.getSymB()->getSymbol()));
+    return Offset;
+  }
+
   assert(SD->getFragment() && "Invalid getOffset() on undefined symbol!");
   return getFragmentOffset(SD->getFragment()) + SD->getOffset();
 }

Added: llvm/trunk/test/MC/MachO/variable-errors.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/MachO/variable-errors.s?rev=130524&view=auto
==============================================================================
--- llvm/trunk/test/MC/MachO/variable-errors.s (added)
+++ llvm/trunk/test/MC/MachO/variable-errors.s Fri Apr 29 13:20:20 2011
@@ -0,0 +1,8 @@
+// RUN: not llvm-mc -triple x86_64-apple-darwin10 %s -filetype=obj -o %t.o 2> %t.err
+// RUN: FileCheck < %t.err %s
+
+        .data
+t0_a:
+t0_x = t0_a - t0_b
+// CHECK: unable to evaluate offset to undefined symbol 't0_b'
+	.long	t0_x