[DebugInfo] Introduce DW_OP_LLVM_convert
Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.
The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.
For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.
This is a recommit of r356442 with trivial fixes for the failing tests.
Differential Revision: https://reviews.llvm.org/D56587
llvm-svn: 356451
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 0a30ede..e6913bc 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -17,6 +17,7 @@
#include "DwarfUnit.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
@@ -1185,3 +1186,27 @@
: dwarf::DW_AT_GNU_addr_base,
Label, TLOF.getDwarfAddrSection()->getBeginSymbol());
}
+
+void DwarfCompileUnit::addBaseTypeRef(DIEValueList &Die, int64_t Idx) {
+ Die.addValue(DIEValueAllocator, (dwarf::Attribute)0, dwarf::DW_FORM_udata,
+ new (DIEValueAllocator) DIEBaseTypeRef(this, Idx));
+}
+
+void DwarfCompileUnit::createBaseTypeDIEs() {
+ // Insert the base_type DIEs directly after the CU so that their offsets will
+ // fit in the fixed size ULEB128 used inside the location expressions.
+ // Maintain order by iterating backwards and inserting to the front of CU
+ // child list.
+ for (auto &Btr : reverse(ExprRefedBaseTypes)) {
+ DIE &Die = getUnitDie().addChildFront(
+ DIE::get(DIEValueAllocator, dwarf::DW_TAG_base_type));
+ SmallString<32> Str;
+ addString(Die, dwarf::DW_AT_name,
+ Twine(dwarf::AttributeEncodingString(Btr.Encoding) +
+ "_" + Twine(Btr.BitSize)).toStringRef(Str));
+ addUInt(Die, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1, Btr.Encoding);
+ addUInt(Die, dwarf::DW_AT_byte_size, None, Btr.BitSize / 8);
+
+ Btr.Die = &Die;
+ }
+}