llvm/lib/Support/Dwarf.cpp
Adrian Prantl 460dd60c1a [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288683 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-05 18:04:47 +00:00

386 lines
12 KiB
C++

//===-- llvm/Support/Dwarf.cpp - Dwarf Framework ----------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains support for generic dwarf information.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Dwarf.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
using namespace dwarf;
StringRef llvm::dwarf::TagString(unsigned Tag) {
switch (Tag) {
default:
return StringRef();
#define HANDLE_DW_TAG(ID, NAME) \
case DW_TAG_##NAME: \
return "DW_TAG_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
unsigned llvm::dwarf::getTag(StringRef TagString) {
return StringSwitch<unsigned>(TagString)
#define HANDLE_DW_TAG(ID, NAME) .Case("DW_TAG_" #NAME, DW_TAG_##NAME)
#include "llvm/Support/Dwarf.def"
.Default(DW_TAG_invalid);
}
StringRef llvm::dwarf::ChildrenString(unsigned Children) {
switch (Children) {
case DW_CHILDREN_no: return "DW_CHILDREN_no";
case DW_CHILDREN_yes: return "DW_CHILDREN_yes";
}
return StringRef();
}
StringRef llvm::dwarf::AttributeString(unsigned Attribute) {
switch (Attribute) {
default:
return StringRef();
#define HANDLE_DW_AT(ID, NAME) \
case DW_AT_##NAME: \
return "DW_AT_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
StringRef llvm::dwarf::FormEncodingString(unsigned Encoding) {
switch (Encoding) {
default:
return StringRef();
#define HANDLE_DW_FORM(ID, NAME) \
case DW_FORM_##NAME: \
return "DW_FORM_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
StringRef llvm::dwarf::OperationEncodingString(unsigned Encoding) {
switch (Encoding) {
default:
return StringRef();
#define HANDLE_DW_OP(ID, NAME) \
case DW_OP_##NAME: \
return "DW_OP_" #NAME;
#include "llvm/Support/Dwarf.def"
case DW_OP_LLVM_fragment:
return "DW_OP_LLVM_fragment";
}
}
unsigned llvm::dwarf::getOperationEncoding(StringRef OperationEncodingString) {
return StringSwitch<unsigned>(OperationEncodingString)
#define HANDLE_DW_OP(ID, NAME) .Case("DW_OP_" #NAME, DW_OP_##NAME)
#include "llvm/Support/Dwarf.def"
.Case("DW_OP_LLVM_fragment", DW_OP_LLVM_fragment)
.Default(0);
}
StringRef llvm::dwarf::AttributeEncodingString(unsigned Encoding) {
switch (Encoding) {
default:
return StringRef();
#define HANDLE_DW_ATE(ID, NAME) \
case DW_ATE_##NAME: \
return "DW_ATE_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
unsigned llvm::dwarf::getAttributeEncoding(StringRef EncodingString) {
return StringSwitch<unsigned>(EncodingString)
#define HANDLE_DW_ATE(ID, NAME) .Case("DW_ATE_" #NAME, DW_ATE_##NAME)
#include "llvm/Support/Dwarf.def"
.Default(0);
}
StringRef llvm::dwarf::DecimalSignString(unsigned Sign) {
switch (Sign) {
case DW_DS_unsigned: return "DW_DS_unsigned";
case DW_DS_leading_overpunch: return "DW_DS_leading_overpunch";
case DW_DS_trailing_overpunch: return "DW_DS_trailing_overpunch";
case DW_DS_leading_separate: return "DW_DS_leading_separate";
case DW_DS_trailing_separate: return "DW_DS_trailing_separate";
}
return StringRef();
}
StringRef llvm::dwarf::EndianityString(unsigned Endian) {
switch (Endian) {
case DW_END_default: return "DW_END_default";
case DW_END_big: return "DW_END_big";
case DW_END_little: return "DW_END_little";
case DW_END_lo_user: return "DW_END_lo_user";
case DW_END_hi_user: return "DW_END_hi_user";
}
return StringRef();
}
StringRef llvm::dwarf::AccessibilityString(unsigned Access) {
switch (Access) {
// Accessibility codes
case DW_ACCESS_public: return "DW_ACCESS_public";
case DW_ACCESS_protected: return "DW_ACCESS_protected";
case DW_ACCESS_private: return "DW_ACCESS_private";
}
return StringRef();
}
StringRef llvm::dwarf::VisibilityString(unsigned Visibility) {
switch (Visibility) {
case DW_VIS_local: return "DW_VIS_local";
case DW_VIS_exported: return "DW_VIS_exported";
case DW_VIS_qualified: return "DW_VIS_qualified";
}
return StringRef();
}
StringRef llvm::dwarf::VirtualityString(unsigned Virtuality) {
switch (Virtuality) {
default:
return StringRef();
#define HANDLE_DW_VIRTUALITY(ID, NAME) \
case DW_VIRTUALITY_##NAME: \
return "DW_VIRTUALITY_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
unsigned llvm::dwarf::getVirtuality(StringRef VirtualityString) {
return StringSwitch<unsigned>(VirtualityString)
#define HANDLE_DW_VIRTUALITY(ID, NAME) \
.Case("DW_VIRTUALITY_" #NAME, DW_VIRTUALITY_##NAME)
#include "llvm/Support/Dwarf.def"
.Default(DW_VIRTUALITY_invalid);
}
StringRef llvm::dwarf::LanguageString(unsigned Language) {
switch (Language) {
default:
return StringRef();
#define HANDLE_DW_LANG(ID, NAME) \
case DW_LANG_##NAME: \
return "DW_LANG_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
unsigned llvm::dwarf::getLanguage(StringRef LanguageString) {
return StringSwitch<unsigned>(LanguageString)
#define HANDLE_DW_LANG(ID, NAME) .Case("DW_LANG_" #NAME, DW_LANG_##NAME)
#include "llvm/Support/Dwarf.def"
.Default(0);
}
StringRef llvm::dwarf::CaseString(unsigned Case) {
switch (Case) {
case DW_ID_case_sensitive: return "DW_ID_case_sensitive";
case DW_ID_up_case: return "DW_ID_up_case";
case DW_ID_down_case: return "DW_ID_down_case";
case DW_ID_case_insensitive: return "DW_ID_case_insensitive";
}
return StringRef();
}
StringRef llvm::dwarf::ConventionString(unsigned CC) {
switch (CC) {
default:
return StringRef();
#define HANDLE_DW_CC(ID, NAME) \
case DW_CC_##NAME: \
return "DW_CC_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
unsigned llvm::dwarf::getCallingConvention(StringRef CCString) {
return StringSwitch<unsigned>(CCString)
#define HANDLE_DW_CC(ID, NAME) .Case("DW_CC_" #NAME, DW_CC_##NAME)
#include "llvm/Support/Dwarf.def"
.Default(0);
}
StringRef llvm::dwarf::InlineCodeString(unsigned Code) {
switch (Code) {
case DW_INL_not_inlined: return "DW_INL_not_inlined";
case DW_INL_inlined: return "DW_INL_inlined";
case DW_INL_declared_not_inlined: return "DW_INL_declared_not_inlined";
case DW_INL_declared_inlined: return "DW_INL_declared_inlined";
}
return StringRef();
}
StringRef llvm::dwarf::ArrayOrderString(unsigned Order) {
switch (Order) {
case DW_ORD_row_major: return "DW_ORD_row_major";
case DW_ORD_col_major: return "DW_ORD_col_major";
}
return StringRef();
}
StringRef llvm::dwarf::DiscriminantString(unsigned Discriminant) {
switch (Discriminant) {
case DW_DSC_label: return "DW_DSC_label";
case DW_DSC_range: return "DW_DSC_range";
}
return StringRef();
}
StringRef llvm::dwarf::LNStandardString(unsigned Standard) {
switch (Standard) {
default:
return StringRef();
#define HANDLE_DW_LNS(ID, NAME) \
case DW_LNS_##NAME: \
return "DW_LNS_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
StringRef llvm::dwarf::LNExtendedString(unsigned Encoding) {
switch (Encoding) {
default:
return StringRef();
#define HANDLE_DW_LNE(ID, NAME) \
case DW_LNE_##NAME: \
return "DW_LNE_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
StringRef llvm::dwarf::MacinfoString(unsigned Encoding) {
switch (Encoding) {
// Macinfo Type Encodings
case DW_MACINFO_define: return "DW_MACINFO_define";
case DW_MACINFO_undef: return "DW_MACINFO_undef";
case DW_MACINFO_start_file: return "DW_MACINFO_start_file";
case DW_MACINFO_end_file: return "DW_MACINFO_end_file";
case DW_MACINFO_vendor_ext: return "DW_MACINFO_vendor_ext";
case DW_MACINFO_invalid: return "DW_MACINFO_invalid";
}
return StringRef();
}
unsigned llvm::dwarf::getMacinfo(StringRef MacinfoString) {
return StringSwitch<unsigned>(MacinfoString)
.Case("DW_MACINFO_define", DW_MACINFO_define)
.Case("DW_MACINFO_undef", DW_MACINFO_undef)
.Case("DW_MACINFO_start_file", DW_MACINFO_start_file)
.Case("DW_MACINFO_end_file", DW_MACINFO_end_file)
.Case("DW_MACINFO_vendor_ext", DW_MACINFO_vendor_ext)
.Default(DW_MACINFO_invalid);
}
StringRef llvm::dwarf::CallFrameString(unsigned Encoding) {
switch (Encoding) {
default:
return StringRef();
#define HANDLE_DW_CFA(ID, NAME) \
case DW_CFA_##NAME: \
return "DW_CFA_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
StringRef llvm::dwarf::ApplePropertyString(unsigned Prop) {
switch (Prop) {
default:
return StringRef();
#define HANDLE_DW_APPLE_PROPERTY(ID, NAME) \
case DW_APPLE_PROPERTY_##NAME: \
return "DW_APPLE_PROPERTY_" #NAME;
#include "llvm/Support/Dwarf.def"
}
}
StringRef llvm::dwarf::AtomTypeString(unsigned AT) {
switch (AT) {
case dwarf::DW_ATOM_null:
return "DW_ATOM_null";
case dwarf::DW_ATOM_die_offset:
return "DW_ATOM_die_offset";
case DW_ATOM_cu_offset:
return "DW_ATOM_cu_offset";
case DW_ATOM_die_tag:
return "DW_ATOM_die_tag";
case DW_ATOM_type_flags:
return "DW_ATOM_type_flags";
}
return StringRef();
}
StringRef llvm::dwarf::GDBIndexEntryKindString(GDBIndexEntryKind Kind) {
switch (Kind) {
case GIEK_NONE:
return "NONE";
case GIEK_TYPE:
return "TYPE";
case GIEK_VARIABLE:
return "VARIABLE";
case GIEK_FUNCTION:
return "FUNCTION";
case GIEK_OTHER:
return "OTHER";
case GIEK_UNUSED5:
return "UNUSED5";
case GIEK_UNUSED6:
return "UNUSED6";
case GIEK_UNUSED7:
return "UNUSED7";
}
llvm_unreachable("Unknown GDBIndexEntryKind value");
}
StringRef
llvm::dwarf::GDBIndexEntryLinkageString(GDBIndexEntryLinkage Linkage) {
switch (Linkage) {
case GIEL_EXTERNAL:
return "EXTERNAL";
case GIEL_STATIC:
return "STATIC";
}
llvm_unreachable("Unknown GDBIndexEntryLinkage value");
}
StringRef llvm::dwarf::AttributeValueString(uint16_t Attr, unsigned Val) {
switch (Attr) {
case DW_AT_accessibility:
return AccessibilityString(Val);
case DW_AT_virtuality:
return VirtualityString(Val);
case DW_AT_language:
return LanguageString(Val);
case DW_AT_encoding:
return AttributeEncodingString(Val);
case DW_AT_decimal_sign:
return DecimalSignString(Val);
case DW_AT_endianity:
return EndianityString(Val);
case DW_AT_visibility:
return VisibilityString(Val);
case DW_AT_identifier_case:
return CaseString(Val);
case DW_AT_calling_convention:
return ConventionString(Val);
case DW_AT_inline:
return InlineCodeString(Val);
case DW_AT_ordering:
return ArrayOrderString(Val);
case DW_AT_discr_value:
return DiscriminantString(Val);
}
return StringRef();
}