When the diagnostic text is simply "%0", sanitize the string for any

unprintable characters.  Fixes PR22048.

llvm-svn: 225423

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index a8929466084..83228ad3c55 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CrashRecoveryContext.h"
+#include "llvm/Support/Locale.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace clang;
@@ -629,6 +630,20 @@ void Diagnostic::
 FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
                  SmallVectorImpl<char> &OutStr) const {
 
+  // When the diagnostic string is only "%0", the entire string is being given
+  // by an outside source.  Remove unprintable characters from this string
+  // and skip all the other string processing.
+  if (DiagEnd - DiagStr == 2 && DiagStr[0] == '%' && DiagStr[1] == '0' &&
+      getArgKind(0) == DiagnosticsEngine::ak_std_string) {
+    const std::string &S = getArgStdStr(0);
+    for (char c : S) {
+      if (llvm::sys::locale::isPrint(c) || c == '\t') {
+        OutStr.push_back(c);
+      }
+    }
+    return;
+  }
+
   /// FormattedArgs - Keep track of all of the arguments formatted by
   /// ConvertArgToString and pass them into subsequent calls to
   /// ConvertArgToString, allowing the implementation to avoid redundancies in