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2417618d5ca4b151908df09d8e3a00a49f029222
clang-p2996/llvm/lib/CodeGen/MIRParser/MILexer.cpp
Sami Tolvanen cff5bef948 KCFI sanitizer 
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.

Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.

KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.

A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:

```
.c:
  int f(void);
  int (*p)(void) = f;
  p();

.s:
  .4byte __kcfi_typeid_f
  .global f
  f:
    ...
```

Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.

As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.

Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.

Relands 67504c9549 with a fix for
32-bit builds.

Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay

Differential Revision: https://reviews.llvm.org/D119296
2022-08-24 22:41:38 +00:00

764 lines
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//===- MILexer.cpp - Machine instructions lexer implementation ------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the lexing of machine instructions.
//
//===----------------------------------------------------------------------===//
#include "MILexer.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Twine.h"
#include <cassert>
#include <cctype>
#include <string>
using namespace llvm;
namespace {
using ErrorCallbackType =
function_ref<void(StringRef::iterator Loc, const Twine &)>;
/// This class provides a way to iterate and get characters from the source
/// string.
class Cursor {
const char *Ptr = nullptr;
const char *End = nullptr;
public:
Cursor(NoneType) {}
explicit Cursor(StringRef Str) {
Ptr = Str.data();
End = Ptr + Str.size();
}
bool isEOF() const { return Ptr == End; }
char peek(int I = 0) const { return End - Ptr <= I ? 0 : Ptr[I]; }
void advance(unsigned I = 1) { Ptr += I; }
StringRef remaining() const { return StringRef(Ptr, End - Ptr); }
StringRef upto(Cursor C) const {
assert(C.Ptr >= Ptr && C.Ptr <= End);
return StringRef(Ptr, C.Ptr - Ptr);
}
StringRef::iterator location() const { return Ptr; }
operator bool() const { return Ptr != nullptr; }
};
} // end anonymous namespace
MIToken &MIToken::reset(TokenKind Kind, StringRef Range) {
this->Kind = Kind;
this->Range = Range;
return *this;
}
MIToken &MIToken::setStringValue(StringRef StrVal) {
StringValue = StrVal;
return *this;
}
MIToken &MIToken::setOwnedStringValue(std::string StrVal) {
StringValueStorage = std::move(StrVal);
StringValue = StringValueStorage;
return *this;
}
MIToken &MIToken::setIntegerValue(APSInt IntVal) {
this->IntVal = std::move(IntVal);
return *this;
}
/// Skip the leading whitespace characters and return the updated cursor.
static Cursor skipWhitespace(Cursor C) {
while (isblank(C.peek()))
C.advance();
return C;
}
static bool isNewlineChar(char C) { return C == '\n' || C == '\r'; }
/// Skip a line comment and return the updated cursor.
static Cursor skipComment(Cursor C) {
if (C.peek() != ';')
return C;
while (!isNewlineChar(C.peek()) && !C.isEOF())
C.advance();
return C;
}
/// Machine operands can have comments, enclosed between /* and */.
/// This eats up all tokens, including /* and */.
static Cursor skipMachineOperandComment(Cursor C) {
if (C.peek() != '/' || C.peek(1) != '*')
return C;
while (C.peek() != '*' || C.peek(1) != '/')
C.advance();
C.advance();
C.advance();
return C;
}
/// Return true if the given character satisfies the following regular
/// expression: [-a-zA-Z$._0-9]
static bool isIdentifierChar(char C) {
return isalpha(C) || isdigit(C) || C == '_' || C == '-' || C == '.' ||
C == '$';
}
/// Unescapes the given string value.
///
/// Expects the string value to be quoted.
static std::string unescapeQuotedString(StringRef Value) {
assert(Value.front() == '"' && Value.back() == '"');
Cursor C = Cursor(Value.substr(1, Value.size() - 2));
std::string Str;
Str.reserve(C.remaining().size());
while (!C.isEOF()) {
char Char = C.peek();
if (Char == '\\') {
if (C.peek(1) == '\\') {
// Two '\' become one
Str += '\\';
C.advance(2);
continue;
}
if (isxdigit(C.peek(1)) && isxdigit(C.peek(2))) {
Str += hexDigitValue(C.peek(1)) * 16 + hexDigitValue(C.peek(2));
C.advance(3);
continue;
}
}
Str += Char;
C.advance();
}
return Str;
}
/// Lex a string constant using the following regular expression: \"[^\"]*\"
static Cursor lexStringConstant(Cursor C, ErrorCallbackType ErrorCallback) {
assert(C.peek() == '"');
for (C.advance(); C.peek() != '"'; C.advance()) {
if (C.isEOF() || isNewlineChar(C.peek())) {
ErrorCallback(
C.location(),
"end of machine instruction reached before the closing '\"'");
return None;
}
}
C.advance();
return C;
}
static Cursor lexName(Cursor C, MIToken &Token, MIToken::TokenKind Type,
unsigned PrefixLength, ErrorCallbackType ErrorCallback) {
auto Range = C;
C.advance(PrefixLength);
if (C.peek() == '"') {
if (Cursor R = lexStringConstant(C, ErrorCallback)) {
StringRef String = Range.upto(R);
Token.reset(Type, String)
.setOwnedStringValue(
unescapeQuotedString(String.drop_front(PrefixLength)));
return R;
}
Token.reset(MIToken::Error, Range.remaining());
return Range;
}
while (isIdentifierChar(C.peek()))
C.advance();
Token.reset(Type, Range.upto(C))
.setStringValue(Range.upto(C).drop_front(PrefixLength));
return C;
}
static MIToken::TokenKind getIdentifierKind(StringRef Identifier) {
return StringSwitch<MIToken::TokenKind>(Identifier)
.Case("_", MIToken::underscore)
.Case("implicit", MIToken::kw_implicit)
.Case("implicit-def", MIToken::kw_implicit_define)
.Case("def", MIToken::kw_def)
.Case("dead", MIToken::kw_dead)
.Case("killed", MIToken::kw_killed)
.Case("undef", MIToken::kw_undef)
.Case("internal", MIToken::kw_internal)
.Case("early-clobber", MIToken::kw_early_clobber)
.Case("debug-use", MIToken::kw_debug_use)
.Case("renamable", MIToken::kw_renamable)
.Case("tied-def", MIToken::kw_tied_def)
.Case("frame-setup", MIToken::kw_frame_setup)
.Case("frame-destroy", MIToken::kw_frame_destroy)
.Case("nnan", MIToken::kw_nnan)
.Case("ninf", MIToken::kw_ninf)
.Case("nsz", MIToken::kw_nsz)
.Case("arcp", MIToken::kw_arcp)
.Case("contract", MIToken::kw_contract)
.Case("afn", MIToken::kw_afn)
.Case("reassoc", MIToken::kw_reassoc)
.Case("nuw", MIToken::kw_nuw)
.Case("nsw", MIToken::kw_nsw)
.Case("exact", MIToken::kw_exact)
.Case("nofpexcept", MIToken::kw_nofpexcept)
.Case("debug-location", MIToken::kw_debug_location)
.Case("debug-instr-number", MIToken::kw_debug_instr_number)
.Case("same_value", MIToken::kw_cfi_same_value)
.Case("offset", MIToken::kw_cfi_offset)
.Case("rel_offset", MIToken::kw_cfi_rel_offset)
.Case("def_cfa_register", MIToken::kw_cfi_def_cfa_register)
.Case("def_cfa_offset", MIToken::kw_cfi_def_cfa_offset)
.Case("adjust_cfa_offset", MIToken::kw_cfi_adjust_cfa_offset)
.Case("escape", MIToken::kw_cfi_escape)
.Case("def_cfa", MIToken::kw_cfi_def_cfa)
.Case("llvm_def_aspace_cfa", MIToken::kw_cfi_llvm_def_aspace_cfa)
.Case("remember_state", MIToken::kw_cfi_remember_state)
.Case("restore", MIToken::kw_cfi_restore)
.Case("restore_state", MIToken::kw_cfi_restore_state)
.Case("undefined", MIToken::kw_cfi_undefined)
.Case("register", MIToken::kw_cfi_register)
.Case("window_save", MIToken::kw_cfi_window_save)
.Case("negate_ra_sign_state",
MIToken::kw_cfi_aarch64_negate_ra_sign_state)
.Case("blockaddress", MIToken::kw_blockaddress)
.Case("intrinsic", MIToken::kw_intrinsic)
.Case("target-index", MIToken::kw_target_index)
.Case("half", MIToken::kw_half)
.Case("float", MIToken::kw_float)
.Case("double", MIToken::kw_double)
.Case("x86_fp80", MIToken::kw_x86_fp80)
.Case("fp128", MIToken::kw_fp128)
.Case("ppc_fp128", MIToken::kw_ppc_fp128)
.Case("target-flags", MIToken::kw_target_flags)
.Case("volatile", MIToken::kw_volatile)
.Case("non-temporal", MIToken::kw_non_temporal)
.Case("dereferenceable", MIToken::kw_dereferenceable)
.Case("invariant", MIToken::kw_invariant)
.Case("align", MIToken::kw_align)
.Case("basealign", MIToken::kw_basealign)
.Case("addrspace", MIToken::kw_addrspace)
.Case("stack", MIToken::kw_stack)
.Case("got", MIToken::kw_got)
.Case("jump-table", MIToken::kw_jump_table)
.Case("constant-pool", MIToken::kw_constant_pool)
.Case("call-entry", MIToken::kw_call_entry)
.Case("custom", MIToken::kw_custom)
.Case("liveout", MIToken::kw_liveout)
.Case("landing-pad", MIToken::kw_landing_pad)
.Case("inlineasm-br-indirect-target",
MIToken::kw_inlineasm_br_indirect_target)
.Case("ehfunclet-entry", MIToken::kw_ehfunclet_entry)
.Case("liveins", MIToken::kw_liveins)
.Case("successors", MIToken::kw_successors)
.Case("floatpred", MIToken::kw_floatpred)
.Case("intpred", MIToken::kw_intpred)
.Case("shufflemask", MIToken::kw_shufflemask)
.Case("pre-instr-symbol", MIToken::kw_pre_instr_symbol)
.Case("post-instr-symbol", MIToken::kw_post_instr_symbol)
.Case("heap-alloc-marker", MIToken::kw_heap_alloc_marker)
.Case("cfi-type", MIToken::kw_cfi_type)
.Case("bbsections", MIToken::kw_bbsections)
.Case("unknown-size", MIToken::kw_unknown_size)
.Case("unknown-address", MIToken::kw_unknown_address)
.Case("distinct", MIToken::kw_distinct)
.Case("ir-block-address-taken", MIToken::kw_ir_block_address_taken)
.Case("machine-block-address-taken", MIToken::kw_machine_block_address_taken)
.Default(MIToken::Identifier);
}
static Cursor maybeLexIdentifier(Cursor C, MIToken &Token) {
if (!isalpha(C.peek()) && C.peek() != '_')
return None;
auto Range = C;
while (isIdentifierChar(C.peek()))
C.advance();
auto Identifier = Range.upto(C);
Token.reset(getIdentifierKind(Identifier), Identifier)
.setStringValue(Identifier);
return C;
}
static Cursor maybeLexMachineBasicBlock(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
bool IsReference = C.remaining().startswith("%bb.");
if (!IsReference && !C.remaining().startswith("bb."))
return None;
auto Range = C;
unsigned PrefixLength = IsReference ? 4 : 3;
C.advance(PrefixLength); // Skip '%bb.' or 'bb.'
if (!isdigit(C.peek())) {
Token.reset(MIToken::Error, C.remaining());
ErrorCallback(C.location(), "expected a number after '%bb.'");
return C;
}
auto NumberRange = C;
while (isdigit(C.peek()))
C.advance();
StringRef Number = NumberRange.upto(C);
unsigned StringOffset = PrefixLength + Number.size(); // Drop '%bb.<id>'
// TODO: The format bb.<id>.<irname> is supported only when it's not a
// reference. Once we deprecate the format where the irname shows up, we
// should only lex forward if it is a reference.
if (C.peek() == '.') {
C.advance(); // Skip '.'
++StringOffset;
while (isIdentifierChar(C.peek()))
C.advance();
}
Token.reset(IsReference ? MIToken::MachineBasicBlock
: MIToken::MachineBasicBlockLabel,
Range.upto(C))
.setIntegerValue(APSInt(Number))
.setStringValue(Range.upto(C).drop_front(StringOffset));
return C;
}
static Cursor maybeLexIndex(Cursor C, MIToken &Token, StringRef Rule,
MIToken::TokenKind Kind) {
if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
return None;
auto Range = C;
C.advance(Rule.size());
auto NumberRange = C;
while (isdigit(C.peek()))
C.advance();
Token.reset(Kind, Range.upto(C)).setIntegerValue(APSInt(NumberRange.upto(C)));
return C;
}
static Cursor maybeLexIndexAndName(Cursor C, MIToken &Token, StringRef Rule,
MIToken::TokenKind Kind) {
if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
return None;
auto Range = C;
C.advance(Rule.size());
auto NumberRange = C;
while (isdigit(C.peek()))
C.advance();
StringRef Number = NumberRange.upto(C);
unsigned StringOffset = Rule.size() + Number.size();
if (C.peek() == '.') {
C.advance();
++StringOffset;
while (isIdentifierChar(C.peek()))
C.advance();
}
Token.reset(Kind, Range.upto(C))
.setIntegerValue(APSInt(Number))
.setStringValue(Range.upto(C).drop_front(StringOffset));
return C;
}
static Cursor maybeLexJumpTableIndex(Cursor C, MIToken &Token) {
return maybeLexIndex(C, Token, "%jump-table.", MIToken::JumpTableIndex);
}
static Cursor maybeLexStackObject(Cursor C, MIToken &Token) {
return maybeLexIndexAndName(C, Token, "%stack.", MIToken::StackObject);
}
static Cursor maybeLexFixedStackObject(Cursor C, MIToken &Token) {
return maybeLexIndex(C, Token, "%fixed-stack.", MIToken::FixedStackObject);
}
static Cursor maybeLexConstantPoolItem(Cursor C, MIToken &Token) {
return maybeLexIndex(C, Token, "%const.", MIToken::ConstantPoolItem);
}
static Cursor maybeLexSubRegisterIndex(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
const StringRef Rule = "%subreg.";
if (!C.remaining().startswith(Rule))
return None;
return lexName(C, Token, MIToken::SubRegisterIndex, Rule.size(),
ErrorCallback);
}
static Cursor maybeLexIRBlock(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
const StringRef Rule = "%ir-block.";
if (!C.remaining().startswith(Rule))
return None;
if (isdigit(C.peek(Rule.size())))
return maybeLexIndex(C, Token, Rule, MIToken::IRBlock);
return lexName(C, Token, MIToken::NamedIRBlock, Rule.size(), ErrorCallback);
}
static Cursor maybeLexIRValue(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
const StringRef Rule = "%ir.";
if (!C.remaining().startswith(Rule))
return None;
if (isdigit(C.peek(Rule.size())))
return maybeLexIndex(C, Token, Rule, MIToken::IRValue);
return lexName(C, Token, MIToken::NamedIRValue, Rule.size(), ErrorCallback);
}
static Cursor maybeLexStringConstant(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
if (C.peek() != '"')
return None;
return lexName(C, Token, MIToken::StringConstant, /*PrefixLength=*/0,
ErrorCallback);
}
static Cursor lexVirtualRegister(Cursor C, MIToken &Token) {
auto Range = C;
C.advance(); // Skip '%'
auto NumberRange = C;
while (isdigit(C.peek()))
C.advance();
Token.reset(MIToken::VirtualRegister, Range.upto(C))
.setIntegerValue(APSInt(NumberRange.upto(C)));
return C;
}
/// Returns true for a character allowed in a register name.
static bool isRegisterChar(char C) {
return isIdentifierChar(C) && C != '.';
}
static Cursor lexNamedVirtualRegister(Cursor C, MIToken &Token) {
Cursor Range = C;
C.advance(); // Skip '%'
while (isRegisterChar(C.peek()))
C.advance();
Token.reset(MIToken::NamedVirtualRegister, Range.upto(C))
.setStringValue(Range.upto(C).drop_front(1)); // Drop the '%'
return C;
}
static Cursor maybeLexRegister(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
if (C.peek() != '%' && C.peek() != '$')
return None;
if (C.peek() == '%') {
if (isdigit(C.peek(1)))
return lexVirtualRegister(C, Token);
if (isRegisterChar(C.peek(1)))
return lexNamedVirtualRegister(C, Token);
return None;
}
assert(C.peek() == '$');
auto Range = C;
C.advance(); // Skip '$'
while (isRegisterChar(C.peek()))
C.advance();
Token.reset(MIToken::NamedRegister, Range.upto(C))
.setStringValue(Range.upto(C).drop_front(1)); // Drop the '$'
return C;
}
static Cursor maybeLexGlobalValue(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
if (C.peek() != '@')
return None;
if (!isdigit(C.peek(1)))
return lexName(C, Token, MIToken::NamedGlobalValue, /*PrefixLength=*/1,
ErrorCallback);
auto Range = C;
C.advance(1); // Skip the '@'
auto NumberRange = C;
while (isdigit(C.peek()))
C.advance();
Token.reset(MIToken::GlobalValue, Range.upto(C))
.setIntegerValue(APSInt(NumberRange.upto(C)));
return C;
}
static Cursor maybeLexExternalSymbol(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
if (C.peek() != '&')
return None;
return lexName(C, Token, MIToken::ExternalSymbol, /*PrefixLength=*/1,
ErrorCallback);
}
static Cursor maybeLexMCSymbol(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
const StringRef Rule = "<mcsymbol ";
if (!C.remaining().startswith(Rule))
return None;
auto Start = C;
C.advance(Rule.size());
// Try a simple unquoted name.
if (C.peek() != '"') {
while (isIdentifierChar(C.peek()))
C.advance();
StringRef String = Start.upto(C).drop_front(Rule.size());
if (C.peek() != '>') {
ErrorCallback(C.location(),
"expected the '<mcsymbol ...' to be closed by a '>'");
Token.reset(MIToken::Error, Start.remaining());
return Start;
}
C.advance();
Token.reset(MIToken::MCSymbol, Start.upto(C)).setStringValue(String);
return C;
}
// Otherwise lex out a quoted name.
Cursor R = lexStringConstant(C, ErrorCallback);
if (!R) {
ErrorCallback(C.location(),
"unable to parse quoted string from opening quote");
Token.reset(MIToken::Error, Start.remaining());
return Start;
}
StringRef String = Start.upto(R).drop_front(Rule.size());
if (R.peek() != '>') {
ErrorCallback(R.location(),
"expected the '<mcsymbol ...' to be closed by a '>'");
Token.reset(MIToken::Error, Start.remaining());
return Start;
}
R.advance();
Token.reset(MIToken::MCSymbol, Start.upto(R))
.setOwnedStringValue(unescapeQuotedString(String));
return R;
}
static bool isValidHexFloatingPointPrefix(char C) {
return C == 'H' || C == 'K' || C == 'L' || C == 'M' || C == 'R';
}
static Cursor lexFloatingPointLiteral(Cursor Range, Cursor C, MIToken &Token) {
C.advance();
// Skip over [0-9]*([eE][-+]?[0-9]+)?
while (isdigit(C.peek()))
C.advance();
if ((C.peek() == 'e' || C.peek() == 'E') &&
(isdigit(C.peek(1)) ||
((C.peek(1) == '-' || C.peek(1) == '+') && isdigit(C.peek(2))))) {
C.advance(2);
while (isdigit(C.peek()))
C.advance();
}
Token.reset(MIToken::FloatingPointLiteral, Range.upto(C));
return C;
}
static Cursor maybeLexHexadecimalLiteral(Cursor C, MIToken &Token) {
if (C.peek() != '0' || (C.peek(1) != 'x' && C.peek(1) != 'X'))
return None;
Cursor Range = C;
C.advance(2);
unsigned PrefLen = 2;
if (isValidHexFloatingPointPrefix(C.peek())) {
C.advance();
PrefLen++;
}
while (isxdigit(C.peek()))
C.advance();
StringRef StrVal = Range.upto(C);
if (StrVal.size() <= PrefLen)
return None;
if (PrefLen == 2)
Token.reset(MIToken::HexLiteral, Range.upto(C));
else // It must be 3, which means that there was a floating-point prefix.
Token.reset(MIToken::FloatingPointLiteral, Range.upto(C));
return C;
}
static Cursor maybeLexNumericalLiteral(Cursor C, MIToken &Token) {
if (!isdigit(C.peek()) && (C.peek() != '-' || !isdigit(C.peek(1))))
return None;
auto Range = C;
C.advance();
while (isdigit(C.peek()))
C.advance();
if (C.peek() == '.')
return lexFloatingPointLiteral(Range, C, Token);
StringRef StrVal = Range.upto(C);
Token.reset(MIToken::IntegerLiteral, StrVal).setIntegerValue(APSInt(StrVal));
return C;
}
static MIToken::TokenKind getMetadataKeywordKind(StringRef Identifier) {
return StringSwitch<MIToken::TokenKind>(Identifier)
.Case("!tbaa", MIToken::md_tbaa)
.Case("!alias.scope", MIToken::md_alias_scope)
.Case("!noalias", MIToken::md_noalias)
.Case("!range", MIToken::md_range)
.Case("!DIExpression", MIToken::md_diexpr)
.Case("!DILocation", MIToken::md_dilocation)
.Default(MIToken::Error);
}
static Cursor maybeLexExclaim(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
if (C.peek() != '!')
return None;
auto Range = C;
C.advance(1);
if (isdigit(C.peek()) || !isIdentifierChar(C.peek())) {
Token.reset(MIToken::exclaim, Range.upto(C));
return C;
}
while (isIdentifierChar(C.peek()))
C.advance();
StringRef StrVal = Range.upto(C);
Token.reset(getMetadataKeywordKind(StrVal), StrVal);
if (Token.isError())
ErrorCallback(Token.location(),
"use of unknown metadata keyword '" + StrVal + "'");
return C;
}
static MIToken::TokenKind symbolToken(char C) {
switch (C) {
case ',':
return MIToken::comma;
case '.':
return MIToken::dot;
case '=':
return MIToken::equal;
case ':':
return MIToken::colon;
case '(':
return MIToken::lparen;
case ')':
return MIToken::rparen;
case '{':
return MIToken::lbrace;
case '}':
return MIToken::rbrace;
case '+':
return MIToken::plus;
case '-':
return MIToken::minus;
case '<':
return MIToken::less;
case '>':
return MIToken::greater;
default:
return MIToken::Error;
}
}
static Cursor maybeLexSymbol(Cursor C, MIToken &Token) {
MIToken::TokenKind Kind;
unsigned Length = 1;
if (C.peek() == ':' && C.peek(1) == ':') {
Kind = MIToken::coloncolon;
Length = 2;
} else
Kind = symbolToken(C.peek());
if (Kind == MIToken::Error)
return None;
auto Range = C;
C.advance(Length);
Token.reset(Kind, Range.upto(C));
return C;
}
static Cursor maybeLexNewline(Cursor C, MIToken &Token) {
if (!isNewlineChar(C.peek()))
return None;
auto Range = C;
C.advance();
Token.reset(MIToken::Newline, Range.upto(C));
return C;
}
static Cursor maybeLexEscapedIRValue(Cursor C, MIToken &Token,
ErrorCallbackType ErrorCallback) {
if (C.peek() != '`')
return None;
auto Range = C;
C.advance();
auto StrRange = C;
while (C.peek() != '`') {
if (C.isEOF() || isNewlineChar(C.peek())) {
ErrorCallback(
C.location(),
"end of machine instruction reached before the closing '`'");
Token.reset(MIToken::Error, Range.remaining());
return C;
}
C.advance();
}
StringRef Value = StrRange.upto(C);
C.advance();
Token.reset(MIToken::QuotedIRValue, Range.upto(C)).setStringValue(Value);
return C;
}
StringRef llvm::lexMIToken(StringRef Source, MIToken &Token,
ErrorCallbackType ErrorCallback) {
auto C = skipComment(skipWhitespace(Cursor(Source)));
if (C.isEOF()) {
Token.reset(MIToken::Eof, C.remaining());
return C.remaining();
}
C = skipMachineOperandComment(C);
if (Cursor R = maybeLexMachineBasicBlock(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexIdentifier(C, Token))
return R.remaining();
if (Cursor R = maybeLexJumpTableIndex(C, Token))
return R.remaining();
if (Cursor R = maybeLexStackObject(C, Token))
return R.remaining();
if (Cursor R = maybeLexFixedStackObject(C, Token))
return R.remaining();
if (Cursor R = maybeLexConstantPoolItem(C, Token))
return R.remaining();
if (Cursor R = maybeLexSubRegisterIndex(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexIRBlock(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexIRValue(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexRegister(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexGlobalValue(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexExternalSymbol(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexMCSymbol(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexHexadecimalLiteral(C, Token))
return R.remaining();
if (Cursor R = maybeLexNumericalLiteral(C, Token))
return R.remaining();
if (Cursor R = maybeLexExclaim(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexSymbol(C, Token))
return R.remaining();
if (Cursor R = maybeLexNewline(C, Token))
return R.remaining();
if (Cursor R = maybeLexEscapedIRValue(C, Token, ErrorCallback))
return R.remaining();
if (Cursor R = maybeLexStringConstant(C, Token, ErrorCallback))
return R.remaining();
Token.reset(MIToken::Error, C.remaining());
ErrorCallback(C.location(),
Twine("unexpected character '") + Twine(C.peek()) + "'");
return C.remaining();
}
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