[LLVMDemangle] Move some utility classes to header files.

In a followup I'm looking to add a Microsoft demangler.  Doing
so needs a lot of the same utility classes and feature test
macros which are already implemented in ItaniumDemangle.cpp.
So move all of these things into header files so that they
can be re-used by a new demangler.

Differential Revision: https://reviews.llvm.org/D49399

llvm-svn: 337217

1 files changed, 5 insertions, 198 deletions

diff --git a/llvm/lib/Demangle/ItaniumDemangle.cpp b/llvm/lib/Demangle/ItaniumDemangle.cpp
index a2743bd..31cac48 100644
--- a/llvm/lib/Demangle/ItaniumDemangle.cpp
+++ b/llvm/lib/Demangle/ItaniumDemangle.cpp
@@ -11,9 +11,11 @@
 // file does not yet support:
 //   - C++ modules TS
 
+#include "Compiler.h"
+#include "StringView.h"
+#include "Utility.h"
 #include "llvm/Demangle/Demangle.h"
 
-#include <algorithm>
 #include <cassert>
 #include <cctype>
 #include <cstdio>
@@ -22,204 +24,9 @@
 #include <numeric>
 #include <vector>
 
-#ifdef _MSC_VER
-// snprintf is implemented in VS 2015
-#if _MSC_VER < 1900
-#define snprintf _snprintf_s
-#endif
-#endif
-
-// A variety of feature test macros copied from include/llvm/Support/Compiler.h
-#ifndef __has_feature
-#define __has_feature(x) 0
-#endif
-
-#ifndef __has_cpp_attribute
-#define __has_cpp_attribute(x) 0
-#endif
-
-#ifndef __has_attribute
-#define __has_attribute(x) 0
-#endif
-
-#ifndef __has_builtin
-#define __has_builtin(x) 0
-#endif
-
-#ifndef LLVM_GNUC_PREREQ
-#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
-#define LLVM_GNUC_PREREQ(maj, min, patch)                                      \
-  ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >=          \
-   ((maj) << 20) + ((min) << 10) + (patch))
-#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
-#define LLVM_GNUC_PREREQ(maj, min, patch)                                      \
-  ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10))
-#else
-#define LLVM_GNUC_PREREQ(maj, min, patch) 0
-#endif
-#endif
-
-#if __has_attribute(used) || LLVM_GNUC_PREREQ(3, 1, 0)
-#define LLVM_ATTRIBUTE_USED __attribute__((__used__))
-#else
-#define LLVM_ATTRIBUTE_USED
-#endif
-
-#if __has_builtin(__builtin_unreachable) || LLVM_GNUC_PREREQ(4, 5, 0)
-#define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
-#elif defined(_MSC_VER)
-#define LLVM_BUILTIN_UNREACHABLE __assume(false)
-#endif
-
-#if __has_attribute(noinline) || LLVM_GNUC_PREREQ(3, 4, 0)
-#define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
-#elif defined(_MSC_VER)
-#define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
-#else
-#define LLVM_ATTRIBUTE_NOINLINE
-#endif
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-#define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
-#else
-#define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
-#endif
-
-#if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
-#define LLVM_FALLTHROUGH [[fallthrough]]
-#elif __has_cpp_attribute(gnu::fallthrough)
-#define LLVM_FALLTHROUGH [[gnu::fallthrough]]
-#elif !__cplusplus
-// Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious
-// error when __has_cpp_attribute is given a scoped attribute in C mode.
-#define LLVM_FALLTHROUGH
-#elif __has_cpp_attribute(clang::fallthrough)
-#define LLVM_FALLTHROUGH [[clang::fallthrough]]
-#else
-#define LLVM_FALLTHROUGH
-#endif
 
 namespace {
 
-class StringView {
-  const char *First;
-  const char *Last;
-
-public:
-  template <size_t N>
-  StringView(const char (&Str)[N]) : First(Str), Last(Str + N - 1) {}
-  StringView(const char *First_, const char *Last_) : First(First_), Last(Last_) {}
-  StringView() : First(nullptr), Last(nullptr) {}
-
-  StringView substr(size_t From, size_t To) {
-    if (To >= size())
-      To = size() - 1;
-    if (From >= size())
-      From = size() - 1;
-    return StringView(First + From, First + To);
-  }
-
-  StringView dropFront(size_t N) const {
-    if (N >= size())
-      N = size() - 1;
-    return StringView(First + N, Last);
-  }
-
-  bool startsWith(StringView Str) const {
-    if (Str.size() > size())
-      return false;
-    return std::equal(Str.begin(), Str.end(), begin());
-  }
-
-  const char &operator[](size_t Idx) const { return *(begin() + Idx); }
-
-  const char *begin() const { return First; }
-  const char *end() const { return Last; }
-  size_t size() const { return static_cast<size_t>(Last - First); }
-  bool empty() const { return First == Last; }
-};
-
-bool operator==(const StringView &LHS, const StringView &RHS) {
-  return LHS.size() == RHS.size() &&
-         std::equal(LHS.begin(), LHS.end(), RHS.begin());
-}
-
-// Stream that AST nodes write their string representation into after the AST
-// has been parsed.
-class OutputStream {
-  char *Buffer;
-  size_t CurrentPosition;
-  size_t BufferCapacity;
-
-  // Ensure there is at least n more positions in buffer.
-  void grow(size_t N) {
-    if (N + CurrentPosition >= BufferCapacity) {
-      BufferCapacity *= 2;
-      if (BufferCapacity < N + CurrentPosition)
-        BufferCapacity = N + CurrentPosition;
-      Buffer = static_cast<char *>(std::realloc(Buffer, BufferCapacity));
-    }
-  }
-
-public:
-  OutputStream(char *StartBuf, size_t Size)
-      : Buffer(StartBuf), CurrentPosition(0), BufferCapacity(Size) {}
-  OutputStream() = default;
-  void reset(char *Buffer_, size_t BufferCapacity_) {
-    CurrentPosition = 0;
-    Buffer = Buffer_;
-    BufferCapacity = BufferCapacity_;
-  }
-
-  /// If a ParameterPackExpansion (or similar type) is encountered, the offset
-  /// into the pack that we're currently printing.
-  unsigned CurrentPackIndex = std::numeric_limits<unsigned>::max();
-  unsigned CurrentPackMax = std::numeric_limits<unsigned>::max();
-
-  OutputStream &operator+=(StringView R) {
-    size_t Size = R.size();
-    if (Size == 0)
-      return *this;
-    grow(Size);
-    memmove(Buffer + CurrentPosition, R.begin(), Size);
-    CurrentPosition += Size;
-    return *this;
-  }
-
-  OutputStream &operator+=(char C) {
-    grow(1);
-    Buffer[CurrentPosition++] = C;
-    return *this;
-  }
-
-  size_t getCurrentPosition() const { return CurrentPosition; }
-  void setCurrentPosition(size_t NewPos) { CurrentPosition = NewPos; }
-
-  char back() const {
-    return CurrentPosition ? Buffer[CurrentPosition - 1] : '\0';
-  }
-
-  bool empty() const { return CurrentPosition == 0; }
-
-  char *getBuffer() { return Buffer; }
-  char *getBufferEnd() { return Buffer + CurrentPosition - 1; }
-  size_t getBufferCapacity() { return BufferCapacity; }
-};
-
-template <class T>
-class SwapAndRestore {
-  T &Restore;
-  T OriginalValue;
-public:
-  SwapAndRestore(T& Restore_, T NewVal)
-      : Restore(Restore_), OriginalValue(Restore) {
-    Restore = std::move(NewVal);
-  }
-  ~SwapAndRestore() { Restore = std::move(OriginalValue); }
-
-  SwapAndRestore(const SwapAndRestore &) = delete;
-  SwapAndRestore &operator=(const SwapAndRestore &) = delete;
-};
 
 // Base class of all AST nodes. The AST is built by the parser, then is
 // traversed by the printLeft/Right functions to produce a demangled string.
@@ -2987,7 +2794,7 @@ Node *Db::parseBaseUnresolvedName() {
 // <unresolved-name>
 //  extension        ::= srN <unresolved-type> [<template-args>] <unresolved-qualifier-level>* E <base-unresolved-name>
 //                   ::= [gs] <base-unresolved-name>                     # x or (with "gs") ::x
-//                   ::= [gs] sr <unresolved-qualifier-level>+ E <base-unresolved-name>  
+//                   ::= [gs] sr <unresolved-qualifier-level>+ E <base-unresolved-name>
 //                                                                       # A::x, N::y, A<T>::z; "gs" means leading "::"
 //                   ::= sr <unresolved-type> <base-unresolved-name>     # T::x / decltype(p)::x
 //  extension        ::= sr <unresolved-type> <template-args> <base-unresolved-name>
@@ -3037,7 +2844,7 @@ Node *Db::parseUnresolvedName() {
     return SoFar;
   }
 
-  // [gs] sr <unresolved-qualifier-level>+ E   <base-unresolved-name>  
+  // [gs] sr <unresolved-qualifier-level>+ E   <base-unresolved-name>
   if (std::isdigit(look())) {
     do {
       Node *Qual = parseSimpleId();