Decouple llvm::SpecialCaseList text representation and its LLVM IR semantics.

Turn llvm::SpecialCaseList into a simple class that parses text files in
a specified format and knows nothing about LLVM IR. Move this class into
LLVMSupport library. Implement two users of this class:
  * DFSanABIList in DFSan instrumentation pass.
  * SanitizerBlacklist in Clang CodeGen library.
The latter will be modified to use actual source-level information from frontend
(source file names) instead of unstable LLVM IR things (LLVM Module identifier).

Remove dependency edge from ClangCodeGen/ClangDriver to LLVMTransformUtils.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212643 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/SpecialCaseList.h

@@ -0,0 +1,94 @@
+//===-- SpecialCaseList.h - special case list for sanitizers ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//===----------------------------------------------------------------------===//
+//
+// This is a utility class used to parse user-provided text files with
+// "special case lists" for code sanitizers. Such files are used to
+// define "ABI list" for DataFlowSanitizer and blacklists for another sanitizers
+// like AddressSanitizer or UndefinedBehaviorSanitizer.
+//
+// Empty lines and lines starting with "#" are ignored. All the rest lines
+// should have the form:
+//   section:wildcard_expression[=category]
+// If category is not specified, it is assumed to be empty string.
+// Definitions of "section" and "category" are sanitizer-specific. For example,
+// sanitizer blacklists support sections "src", "fun" and "global".
+// Wildcard expressions define, respectively, source files, functions or
+// globals which shouldn't be instrumented.
+// Examples of categories:
+//   "functional": used in DFSan to list functions with pure functional
+//                 semantics.
+//   "init": used in ASan blacklist to disable initialization-order bugs
+//           detection for certain globals or source files.
+// Full special case list file example:
+// ---
+// # Blacklisted items:
+// fun:*_ZN4base6subtle*
+// global:*global_with_bad_access_or_initialization*
+// global:*global_with_initialization_issues*=init
+// type:*Namespace::ClassName*=init
+// src:file_with_tricky_code.cc
+// src:ignore-global-initializers-issues.cc=init
+//
+// # Functions with pure functional semantics:
+// fun:cos=functional
+// fun:sin=functional
+// ---
+// Note that the wild card is in fact an llvm::Regex, but * is automatically
+// replaced with .*
+// This is similar to the "ignore" feature of ThreadSanitizer.
+// http://code.google.com/p/data-race-test/wiki/ThreadSanitizerIgnores
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_SPECIALCASELIST_H
+#define LLVM_SUPPORT_SPECIALCASELIST_H
+
+#include "llvm/ADT/StringMap.h"
+
+namespace llvm {
+class MemoryBuffer;
+class Regex;
+class StringRef;
+
+class SpecialCaseList {
+ public:
+  /// Parses the special case list from a file. If Path is empty, returns
+  /// an empty special case list. On failure, returns 0 and writes an error
+  /// message to string.
+  static SpecialCaseList *create(const StringRef Path, std::string &Error);
+  /// Parses the special case list from a memory buffer. On failure, returns
+  /// 0 and writes an error message to string.
+  static SpecialCaseList *create(const MemoryBuffer *MB, std::string &Error);
+  /// Parses the special case list from a file. On failure, reports a fatal
+  /// error.
+  static SpecialCaseList *createOrDie(const StringRef Path);
+
+  ~SpecialCaseList();
+
+  /// Returns true, if special case list contains a line
+  ///   @Section:<E>=@Category
+  /// and @Query satisfies a wildcard expression <E>.
+  bool inSection(const StringRef Section, const StringRef Query,
+                 const StringRef Category = StringRef()) const;
+
+ private:
+  SpecialCaseList(SpecialCaseList const &) LLVM_DELETED_FUNCTION;
+  SpecialCaseList &operator=(SpecialCaseList const &) LLVM_DELETED_FUNCTION;
+
+  struct Entry;
+  StringMap<StringMap<Entry> > Entries;
+
+  SpecialCaseList();
+  /// Parses just-constructed SpecialCaseList entries from a memory buffer.
+  bool parse(const MemoryBuffer *MB, std::string &Error);
+};
+
+}  // namespace llvm
+
+#endif  // LLVM_SUPPORT_SPECIALCASELIST_H
+