[DWARF] Emit DW_AT_call_return_pc as an address
This reverts D53469, which changed llvm's DWARF emission to emit
DW_AT_call_return_pc as a function-local offset. Such an encoding is not
compatible with post-link block re-ordering tools and isn't standards-
compliant.
In addition to reverting back to the original DW_AT_call_return_pc
encoding, teach lldb how to fix up DW_AT_call_return_pc when the address
comes from an object file pointed-to by a debug map. While doing this I
noticed that lldb's support for tail calls that cross a DSO/object file
boundary wasn't covered, so I added tests for that. This latter case
exercises the newly added return PC fixup.
The dsymutil changes in this patch were originally included in D49887:
the associated test should be sufficient to test DW_AT_call_return_pc
encoding purely on the llvm side.
Differential Revision: https://reviews.llvm.org/D72489
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index 8491d07..d659746 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -242,17 +242,12 @@
/// Construct a call site entry DIE describing a call within \p Scope to a
/// callee described by \p CalleeSP.
/// \p IsTail specifies whether the call is a tail call.
- /// \p PCAddr (used for GDB + DWARF 4 tuning) points to the PC value after
- /// the call instruction.
- /// \p PCOffset (used for cases other than GDB + DWARF 4 tuning) must be
- /// non-zero for non-tail calls (in the case of non-gdb tuning, since for
- /// GDB + DWARF 5 tuning we still generate PC info for tail calls) or be the
- /// function-local offset to PC value after the call instruction.
+ /// \p PCAddr points to the PC value after the call instruction.
/// \p CallReg is a register location for an indirect call. For direct calls
/// the \p CallReg is set to 0.
DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP,
bool IsTail, const MCSymbol *PCAddr,
- const MCExpr *PCOffset, unsigned CallReg);
+ unsigned CallReg);
/// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params
/// were collected by the \ref collectCallSiteParameters.
/// Note: The order of parameters does not matter, since debuggers recognize
@@ -340,9 +335,6 @@
/// Add a Dwarf expression attribute data and value.
void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
- /// Add an attribute containing an address expression to \p Die.
- void addAddressExpr(DIE &Die, dwarf::Attribute Attribute, const MCExpr *Expr);
-
void applySubprogramAttributesToDefinition(const DISubprogram *SP,
DIE &SPDie);