[llvm] r352216 - [DiagnosticInfo] Add support for preserving newlines in remark arguments.

[Florian Hahn via llvm-commits]

Author: fhahn
Date: Fri Jan 25 08:59:06 2019
New Revision: 352216

URL: http://llvm.org/viewvc/llvm-project?rev=352216&view=rev
Log:
[DiagnosticInfo] Add support for preserving newlines in remark arguments.

This patch adds a new type StringBlockVal which can be used to emit a
YAML block scalar, which preserves newlines in a multiline string. It
also updates  MappingTraits<DiagnosticInfoOptimizationBase::Argument> to
use it for argument values with more than a single newline.

This is helpful for remarks that want to display more in-depth
information in a more structured way.

Reviewers: thegameg, anemet

Reviewed By: anemet

Subscribers: hfinkel, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D57159

Modified:
    llvm/trunk/lib/IR/DiagnosticInfo.cpp

Modified: llvm/trunk/lib/IR/DiagnosticInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DiagnosticInfo.cpp?rev=352216&r1=352215&r2=352216&view=diff
==============================================================================
--- llvm/trunk/lib/IR/DiagnosticInfo.cpp (original)
+++ llvm/trunk/lib/IR/DiagnosticInfo.cpp Fri Jan 25 08:59:06 2019
@@ -438,11 +438,33 @@ template <> struct MappingTraits<Diagnos
   static const bool flow = true;
 };
 
+/// Helper struct for multiline string block literals. Use this type to preserve
+/// newlines in strings.
+struct StringBlockVal {
+  StringRef Value;
+  StringBlockVal(const std::string &Value) : Value(Value) {}
+};
+
+template <> struct BlockScalarTraits<StringBlockVal> {
+  static void output(const StringBlockVal &S, void *Ctx, raw_ostream &OS) {
+    return ScalarTraits<StringRef>::output(S.Value, Ctx, OS);
+  }
+
+  static StringRef input(StringRef Scalar, void *Ctx, StringBlockVal &S) {
+    return ScalarTraits<StringRef>::input(Scalar, Ctx, S.Value);
+  }
+};
+
 // Implement this as a mapping for now to get proper quotation for the value.
 template <> struct MappingTraits<DiagnosticInfoOptimizationBase::Argument> {
   static void mapping(IO &io, DiagnosticInfoOptimizationBase::Argument &A) {
     assert(io.outputting() && "input not yet implemented");
-    io.mapRequired(A.Key.data(), A.Val);
+    // Emit a string block scalar for multiline strings, to preserve newlines.
+    if (StringRef(A.Val).count('\n') > 1) {
+      StringBlockVal S(A.Val);
+      io.mapRequired(A.Key.data(), S);
+    } else
+      io.mapRequired(A.Key.data(), A.Val);
     if (A.Loc.isValid())
       io.mapOptional("DebugLoc", A.Loc);
   }