MCAsmLayout: Add support for computing the symbol offset of variables. Not
currently used, because variables don't get reported as being "defined".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130524 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 3ebe69c..8360fc9 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -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();
}