[Tooling] add a Heuristic field indicating that a CompileCommand was guessed.

Summary:
Use cases:
 - a tool that dumps the heuristic used for each header in a project can
   be used to evaluate changes to the heuristic
 - we want to expose this information to users in clangd as it affects
   accuracy/reliability of editor features
 - express interpolation tests more directly

Reviewers: ilya-biryukov, klimek

Subscribers: ioeric, kadircet, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60194

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@357770 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/Tooling/InterpolatingCompilationDatabase.cpp b/lib/Tooling/InterpolatingCompilationDatabase.cpp
index 82ae6b6261..5124340892 100644
--- a/lib/Tooling/InterpolatingCompilationDatabase.cpp
+++ b/lib/Tooling/InterpolatingCompilationDatabase.cpp
@@ -226,6 +226,7 @@ struct TransferableCommand {
           LangStandard::getLangStandardForKind(Std).getName()).str());
     }
     Result.CommandLine.push_back(Filename);
+    Result.Heuristic = "inferred from " + Cmd.Filename;
     return Result;
   }