Fixed printing of JS code.

This is a fix/improvement for r23478 ("Fix disassembly redirection from stdout
into a file.").

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/554223002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23792 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/codegen.cc

@@ -189,7 +189,7 @@ void CodeGenerator::PrintCode(Handle<Code> code, CompilationInfo* info) {
             function->end_position() - function->start_position() + 1;
         for (int i = 0; i < source_len; i++) {
           if (stream.HasMore()) {
-            os << AsUC16(stream.GetNext());
+            os << AsReversiblyEscapedUC16(stream.GetNext());
           }
         }
         os << "\n\n";

src/ostreams.cc

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include <algorithm>
+#include <cctype>
 #include <cmath>
 
 #include "src/base/platform/platform.h"  // For isinf/isnan with MSVC
@@ -165,9 +166,10 @@ OFStream& OFStream::flush() {
 
 OStream& operator<<(OStream& os, const AsReversiblyEscapedUC16& c) {
   char buf[10];
-  const char* format = (0x20 <= c.value && c.value <= 0x7F) && (c.value != 0x52)
-                           ? "%c"
-                           : (c.value <= 0xff) ? "\\x%02x" : "\\u%04x";
+  const char* format =
+      (std::isprint(c.value) || std::isspace(c.value)) && c.value != '\\'
+          ? "%c"
+          : (c.value <= 0xff) ? "\\x%02x" : "\\u%04x";
   snprintf(buf, sizeof(buf), format, c.value);
   return os << buf;
 }
@@ -175,9 +177,8 @@ OStream& operator<<(OStream& os, const AsReversiblyEscapedUC16& c) {
 
 OStream& operator<<(OStream& os, const AsUC16& c) {
   char buf[10];
-  const char* format = (0x20 <= c.value && c.value <= 0x7F)
-                           ? "%c"
-                           : (c.value <= 0xff) ? "\\x%02x" : "\\u%04x";
+  const char* format =
+      std::isprint(c.value) ? "%c" : (c.value <= 0xff) ? "\\x%02x" : "\\u%04x";
   snprintf(buf, sizeof(buf), format, c.value);
   return os << buf;
 }

src/ostreams.h

@@ -130,8 +130,8 @@ struct AsReversiblyEscapedUC16 {
 };
 
 
-// Writes the given character to the output escaping everything outside
-// of printable ASCII range. Additionally escapes '\' making escaping
+// Writes the given character to the output escaping everything outside of
+// printable/space ASCII range. Additionally escapes '\' making escaping
 // reversible.
 OStream& operator<<(OStream& os, const AsReversiblyEscapedUC16& c);