[FileCheck] Annotate input dump (3/7)

This patch implements input annotations for diagnostics that report
wrong-line matches for the directives CHECK-NEXT, CHECK-SAME, and
CHECK-EMPTY.  Instead of the usual `^~~`, which is used by later
patches for good matches, these annotations use `!~~` to mark the bad
match ranges so that this category of errors is visually distinct.
Because such matches are errors, these annotates are red when colors
are enabled.

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)
  - 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 check2 < input2 |& sed -n '/^<<<</,$p'
<<<<<<
        1: foo bar
next:2         !~~ error: match on wrong line
>>>>>>

$ cat check2
CHECK: foo
CHECK-NEXT: bar

$ cat input2
foo bar
```

Reviewed By: george.karpenkov, probinson

Differential Revision: https://reviews.llvm.org/D53894

llvm-svn: 349420

1 files changed, 8 insertions, 1 deletions

diff --git a/llvm/utils/FileCheck/FileCheck.cpp b/llvm/utils/FileCheck/FileCheck.cpp
index c6846f7da71..d027f3e6676 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::MatchFinalButWrongLine:
+    return MarkerStyle('!', raw_ostream::RED, "error: match on wrong line");
   case FileCheckDiag::MatchNoneButExpected:
     return MarkerStyle('X', raw_ostream::RED, "error: no match found");
   case FileCheckDiag::MatchFuzzy:
@@ -177,8 +179,13 @@ static void DumpInputAnnotationHelp(raw_ostream &OS) {
 
   // Markers on annotation lines.
   OS << "  - ";
+  WithColor(OS, raw_ostream::SAVEDCOLOR, true) << "!~~";
+  OS << "    marks bad match, such as:\n"
+     << "           - CHECK-NEXT on same line as previous match (error)\n"
+     << "  - ";
   WithColor(OS, raw_ostream::SAVEDCOLOR, true) << "X~~";
-  OS << "    marks search range when no match is found\n"
+  OS << "    marks search range when no match is found, such as:\n"
+     << "           - CHECK-NEXT not found (error)\n"
      << "  - ";
   WithColor(OS, raw_ostream::SAVEDCOLOR, true) << "?";
   OS << "      marks fuzzy match when no match is found\n";