[FileCheck] Annotate input dump (4/7)

This patch implements input annotations for diagnostics that report
unexpected matches for CHECK-NOT.  Like wrong-line matches for
CHECK-NEXT, CHECK-SAME, and CHECK-EMPTY, these annotations mark match
ranges using red `!~~` to indicate bad matches that are errors.

For example:

```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:

  - L:     labels line number L of the input file
  - T:L    labels the only match result for a pattern of type T from line L of
           the check file
  - T:L'N  labels the Nth match result for a pattern of type T from line L of
           the check file
  - !~~    marks bad match, such as:
           - CHECK-NEXT on same line as previous match (error)
           - CHECK-NOT found (error)
  - X~~    marks search range when no match is found, such as:
           - CHECK-NEXT not found (error)
  - ?      marks fuzzy match when no match is found
  - colors error, fuzzy match

If you are not seeing color above or in input dumps, try: -color

$ FileCheck -v -dump-input=always check3 < input3 |& sed -n '/^<<<</,$p'
<<<<<<
       1: abc foobar def
not:2         !~~~~~     error: no match expected
>>>>>>

$ cat check3
CHECK:     abc
CHECK-NOT: foobar
CHECK:     def

$ cat input3
abc foobar def
```

Reviewed By: george.karpenkov, probinson

Differential Revision: https://reviews.llvm.org/D53896

llvm-svn: 349421

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/utils/FileCheck/FileCheck.cpp b/llvm/utils/FileCheck/FileCheck.cpp
index d027f3e6676..1f6caeee2e1 100644
--- a/llvm/utils/FileCheck/FileCheck.cpp
+++ b/llvm/utils/FileCheck/FileCheck.cpp
@@ -143,6 +143,8 @@ struct MarkerStyle {
 
 static MarkerStyle GetMarker(FileCheckDiag::MatchType MatchTy) {
   switch (MatchTy) {
+  case FileCheckDiag::MatchFinalButExcluded:
+    return MarkerStyle('!', raw_ostream::RED, "error: no match expected");
   case FileCheckDiag::MatchFinalButWrongLine:
     return MarkerStyle('!', raw_ostream::RED, "error: match on wrong line");
   case FileCheckDiag::MatchNoneButExpected:
@@ -182,6 +184,7 @@ static void DumpInputAnnotationHelp(raw_ostream &OS) {
   WithColor(OS, raw_ostream::SAVEDCOLOR, true) << "!~~";
   OS << "    marks bad match, such as:\n"
      << "           - CHECK-NEXT on same line as previous match (error)\n"
+     << "           - CHECK-NOT found (error)\n"
      << "  - ";
   WithColor(OS, raw_ostream::SAVEDCOLOR, true) << "X~~";
   OS << "    marks search range when no match is found, such as:\n"