Refactor FileCheck to make it usable as an API

https://reviews.llvm.org/D50283
reviewed by bogner

This patch refactors FileCheck's implementation into support so it can
be used from C++ in other places (Unit tests).

llvm-svn: 339192

Author: Aditya Nandakumar

llvm/include/llvm/Support/FileCheck.h

@@ -0,0 +1,201 @@
+//==-- llvm/Support/FileCheck.h ---------------------------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file This file has some utilities to use FileCheck as an API
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_FILECHECK_H
+#define LLVM_SUPPORT_FILECHECK_H
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Regex.h"
+#include "llvm/Support/SourceMgr.h"
+#include <vector>
+#include <map>
+
+namespace llvm {
+
+/// Contains info about various FileCheck options.
+struct FileCheckRequest {
+  std::vector<std::string> CheckPrefixes;
+  bool NoCanonicalizeWhiteSpace = false;
+  std::vector<std::string> ImplicitCheckNot;
+  std::vector<std::string> GlobalDefines;
+  bool AllowEmptyInput = false;
+  bool MatchFullLines = false;
+  bool EnableVarScope = false;
+  bool AllowDeprecatedDagOverlap = false;
+  bool Verbose = false;
+  bool VerboseVerbose = false;
+};
+
+
+//===----------------------------------------------------------------------===//
+// Pattern Handling Code.
+//===----------------------------------------------------------------------===//
+
+namespace Check {
+enum FileCheckType {
+  CheckNone = 0,
+  CheckPlain,
+  CheckNext,
+  CheckSame,
+  CheckNot,
+  CheckDAG,
+  CheckLabel,
+  CheckEmpty,
+
+  /// Indicates the pattern only matches the end of file. This is used for
+  /// trailing CHECK-NOTs.
+  CheckEOF,
+
+  /// Marks when parsing found a -NOT check combined with another CHECK suffix.
+  CheckBadNot
+};
+}
+
+class FileCheckPattern {
+  SMLoc PatternLoc;
+
+  /// A fixed string to match as the pattern or empty if this pattern requires
+  /// a regex match.
+  StringRef FixedStr;
+
+  /// A regex string to match as the pattern or empty if this pattern requires
+  /// a fixed string to match.
+  std::string RegExStr;
+
+  /// Entries in this vector map to uses of a variable in the pattern, e.g.
+  /// "foo[[bar]]baz".  In this case, the RegExStr will contain "foobaz" and
+  /// we'll get an entry in this vector that tells us to insert the value of
+  /// bar at offset 3.
+  std::vector<std::pair<StringRef, unsigned>> VariableUses;
+
+  /// Maps definitions of variables to their parenthesized capture numbers.
+  /// 
+  /// E.g. for the pattern "foo[[bar:.*]]baz", VariableDefs will map "bar" to
+  /// 1.
+  std::map<StringRef, unsigned> VariableDefs;
+
+  Check::FileCheckType CheckTy;
+
+  /// Contains the number of line this pattern is in.
+  unsigned LineNumber;
+
+public:
+  explicit FileCheckPattern(Check::FileCheckType Ty)
+      : CheckTy(Ty) {}
+
+  /// Returns the location in source code.
+  SMLoc getLoc() const { return PatternLoc; }
+
+  bool ParsePattern(StringRef PatternStr, StringRef Prefix, SourceMgr &SM,
+                    unsigned LineNumber, const FileCheckRequest &Req);
+  size_t Match(StringRef Buffer, size_t &MatchLen,
+               StringMap<StringRef> &VariableTable) const;
+  void PrintVariableUses(const SourceMgr &SM, StringRef Buffer,
+                         const StringMap<StringRef> &VariableTable,
+                         SMRange MatchRange = None) const;
+  void PrintFuzzyMatch(const SourceMgr &SM, StringRef Buffer,
+                       const StringMap<StringRef> &VariableTable) const;
+
+  bool hasVariable() const {
+    return !(VariableUses.empty() && VariableDefs.empty());
+  }
+
+  Check::FileCheckType getCheckTy() const { return CheckTy; }
+
+private:
+  bool AddRegExToRegEx(StringRef RS, unsigned &CurParen, SourceMgr &SM);
+  void AddBackrefToRegEx(unsigned BackrefNum);
+  unsigned
+  ComputeMatchDistance(StringRef Buffer,
+                       const StringMap<StringRef> &VariableTable) const;
+  bool EvaluateExpression(StringRef Expr, std::string &Value) const;
+  size_t FindRegexVarEnd(StringRef Str, SourceMgr &SM);
+};
+
+//===----------------------------------------------------------------------===//
+// Check Strings.
+//===----------------------------------------------------------------------===//
+
+/// A check that we found in the input file.
+struct FileCheckString {
+  /// The pattern to match.
+  FileCheckPattern Pat;
+
+  /// Which prefix name this check matched.
+  StringRef Prefix;
+
+  /// The location in the match file that the check string was specified.
+  SMLoc Loc;
+
+  /// All of the strings that are disallowed from occurring between this match
+  /// string and the previous one (or start of file).
+  std::vector<FileCheckPattern> DagNotStrings;
+
+  FileCheckString(const FileCheckPattern &P, StringRef S, SMLoc L)
+      : Pat(P), Prefix(S), Loc(L) {}
+
+  size_t Check(const SourceMgr &SM, StringRef Buffer, bool IsLabelScanMode,
+               size_t &MatchLen, StringMap<StringRef> &VariableTable,
+               FileCheckRequest &Req) const;
+
+  bool CheckNext(const SourceMgr &SM, StringRef Buffer) const;
+  bool CheckSame(const SourceMgr &SM, StringRef Buffer) const;
+  bool CheckNot(const SourceMgr &SM, StringRef Buffer,
+                const std::vector<const FileCheckPattern *> &NotStrings,
+                StringMap<StringRef> &VariableTable,
+                const FileCheckRequest &Req) const;
+  size_t CheckDag(const SourceMgr &SM, StringRef Buffer,
+                  std::vector<const FileCheckPattern *> &NotStrings,
+                  StringMap<StringRef> &VariableTable,
+                  const FileCheckRequest &Req) const;
+};
+
+/// FileCheck class takes the request and exposes various methods that
+/// use information from the request.
+class FileCheck {
+  FileCheckRequest Req;
+
+public:
+  FileCheck(FileCheckRequest Req) : Req(Req) {}
+
+  // Combines the check prefixes into a single regex so that we can efficiently
+  // scan for any of the set.
+  //
+  // The semantics are that the longest-match wins which matches our regex
+  // library.
+  Regex buildCheckPrefixRegex();
+
+  /// Read the check file, which specifies the sequence of expected strings.
+  ///
+  /// The strings are added to the CheckStrings vector. Returns true in case of
+  /// an error, false otherwise.
+  bool ReadCheckFile(SourceMgr &SM, StringRef Buffer, Regex &PrefixRE,
+                     std::vector<FileCheckString> &CheckStrings);
+
+  bool ValidateCheckPrefixes();
+
+  /// Canonicalize whitespaces in the file. Line endings are replaced with
+  /// UNIX-style '\n'.
+  StringRef CanonicalizeFile(MemoryBuffer &MB,
+                             SmallVectorImpl<char> &OutputBuffer);
+
+  /// Check the input to FileCheck provided in the \p Buffer against the \p
+  /// CheckStrings read from the check file.
+  ///
+  /// Returns false if the input fails to satisfy the checks.
+  bool CheckInput(SourceMgr &SM, StringRef Buffer,
+                  ArrayRef<FileCheckString> CheckStrings);
+};
+} // namespace llvm
+#endif

llvm/lib/Support/CMakeLists.txt

@@ -71,6 +71,7 @@ add_llvm_library(LLVMSupport
   DJB.cpp
   Error.cpp
   ErrorHandling.cpp
+  FileCheck.cpp
   FileUtilities.cpp
   FileOutputBuffer.cpp
   FoldingSet.cpp