[YAML] Add support for non-printable characters

LLVM IR function names which disable mangling start with '\01'
(https://www.llvm.org/docs/LangRef.html#identifiers).

When an identifier like "\01@abc@" gets dumped to MIR, it is quoted, but
only with single quotes.

http://www.yaml.org/spec/1.2/spec.html#id2770814:

"The allowed character range explicitly excludes the C0 control block
allowed), the surrogate block #xD800-#xDFFF, #xFFFE, and #xFFFF."

http://www.yaml.org/spec/1.2/spec.html#id2776092:

"All non-printable characters must be escaped.
[...]
Note that escape sequences are only interpreted in double-quoted scalars."

This patch adds support for printing escaped non-printable characters
between double quotes if needed.

Should also fix PR31743.

Differential Revision: https://reviews.llvm.org/D41290

llvm-svn: 320996

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Support/Statistic.cpp b/llvm/lib/Support/Statistic.cpp
index 23718bb0e9c..544ae2d0983 100644
--- a/llvm/lib/Support/Statistic.cpp
+++ b/llvm/lib/Support/Statistic.cpp
@@ -168,9 +168,10 @@ void llvm::PrintStatisticsJSON(raw_ostream &OS) {
   const char *delim = "";
   for (const Statistic *Stat : Stats.Stats) {
     OS << delim;
-    assert(!yaml::needsQuotes(Stat->getDebugType()) &&
+    assert(yaml::needsQuotes(Stat->getDebugType()) == yaml::QuotingType::None &&
            "Statistic group/type name is simple.");
-    assert(!yaml::needsQuotes(Stat->getName()) && "Statistic name is simple");
+    assert(yaml::needsQuotes(Stat->getName()) == yaml::QuotingType::None &&
+           "Statistic name is simple");
     OS << "\t\"" << Stat->getDebugType() << '.' << Stat->getName() << "\": "
        << Stat->getValue();
     delim = ",\n";