Revert r336830: [FileCheck] Don't permit overlapping CHECK-DAG

Companion patches are failing to commit, and this patch alone breaks
many tests.

llvm-svn: 336833

1 files changed, 12 insertions, 53 deletions

diff --git a/llvm/utils/FileCheck/FileCheck.cpp b/llvm/utils/FileCheck/FileCheck.cpp
index cd3175f13f0..74157343b43 100644
--- a/llvm/utils/FileCheck/FileCheck.cpp
+++ b/llvm/utils/FileCheck/FileCheck.cpp
@@ -28,7 +28,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cctype>
-#include <list>
 #include <map>
 #include <string>
 #include <system_error>
@@ -83,13 +82,6 @@ static cl::opt<bool> EnableVarScope(
              "do not start with '$' will be reset at the beginning of\n"
              "each CHECK-LABEL block."));
 
-static cl::opt<bool> AllowDeprecatedDagOverlap(
-    "allow-deprecated-dag-overlap", cl::init(false),
-    cl::desc("Enable overlapping among matches in a group of consecutive\n"
-             "CHECK-DAG directives.  This option is deprecated and is only\n"
-             "provided for convenience as old tests are migrated to the new\n"
-             "non-overlapping CHECK-DAG implementation.\n"));
-
 typedef cl::list<std::string>::const_iterator prefix_iterator;
 
 //===----------------------------------------------------------------------===//
@@ -1200,13 +1192,6 @@ size_t CheckString::CheckDag(const SourceMgr &SM, StringRef Buffer,
   size_t LastPos = 0;
   size_t StartPos = LastPos;
 
-  // A sorted list of ranges for non-overlapping dag matches.
-  struct Match {
-    size_t Pos;
-    size_t End;
-  };
-  std::list<Match> Matches;
-
   for (const Pattern &Pat : DagNotStrings) {
     assert((Pat.getCheckTy() == Check::CheckDAG ||
             Pat.getCheckTy() == Check::CheckNot) &&
@@ -1219,42 +1204,19 @@ size_t CheckString::CheckDag(const SourceMgr &SM, StringRef Buffer,
 
     assert((Pat.getCheckTy() == Check::CheckDAG) && "Expect CHECK-DAG!");
 
+    size_t MatchLen = 0, MatchPos;
+
     // CHECK-DAG always matches from the start.
-    size_t MatchLen = 0, MatchPos = StartPos;
-
-    // Search for a match that doesn't overlap a previous match in this
-    // CHECK-DAG group.
-    for (auto MI = Matches.begin(), ME = Matches.end(); true; ++MI) {
-      StringRef MatchBuffer = Buffer.substr(MatchPos);
-      size_t MatchPosBuf = Pat.Match(MatchBuffer, MatchLen, VariableTable);
-      // With a group of CHECK-DAGs, a single mismatching means the match on
-      // that group of CHECK-DAGs fails immediately.
-      if (MatchPosBuf == StringRef::npos) {
-        PrintCheckFailed(SM, Pat.getLoc(), Pat, MatchBuffer, VariableTable);
-        return StringRef::npos;
-      }
-      // Re-calc it as the offset relative to the start of the original string.
-      MatchPos += MatchPosBuf;
-      if (AllowDeprecatedDagOverlap)
-        break;
-      // Iterate previous matches until overlapping match or insertion point.
-      Match M{MatchPos, MatchPos + MatchLen};
-      bool Overlap = false;
-      for (; MI != ME; ++MI) {
-        if (M.Pos < MI->End) {
-          // !Overlap => New match has no overlap and is before this old match.
-          // Overlap => New match overlaps this old match.
-          Overlap = MI->Pos < M.End;
-          break;
-        }
-      }
-      if (!Overlap) {
-        // Insert non-overlapping match into list.
-        Matches.insert(MI, M);
-        break;
-      }
-      MatchPos = MI->End;
+    StringRef MatchBuffer = Buffer.substr(StartPos);
+    MatchPos = Pat.Match(MatchBuffer, MatchLen, VariableTable);
+    // With a group of CHECK-DAGs, a single mismatching means the match on
+    // that group of CHECK-DAGs fails immediately.
+    if (MatchPos == StringRef::npos) {
+      PrintCheckFailed(SM, Pat.getLoc(), Pat, MatchBuffer, VariableTable);
+      return StringRef::npos;
     }
+    // Re-calc it as the offset relative to the start of the original string.
+    MatchPos += StartPos;
 
     if (!NotStrings.empty()) {
       if (MatchPos < LastPos) {
@@ -1276,11 +1238,8 @@ size_t CheckString::CheckDag(const SourceMgr &SM, StringRef Buffer,
         return StringRef::npos;
       }
       // All subsequent CHECK-DAGs should be matched from the farthest
-      // position of all precedent CHECK-DAGs (not including this one).
+      // position of all precedent CHECK-DAGs (including this one.)
       StartPos = LastPos;
-      // Don't waste time checking for (impossible) overlaps before that.
-      Matches.clear();
-      Matches.push_back(Match{MatchPos, MatchPos + MatchLen});
       // If there's CHECK-NOTs between two CHECK-DAGs or from CHECK to
       // CHECK-DAG, verify that there's no 'not' strings occurred in that
       // region.