[llvm] r332675 - Support: Add a raw_ostream::write_zeros() function. NFCI.

[Peter Collingbourne via llvm-commits]

Author: pcc
Date: Thu May 17 15:11:43 2018
New Revision: 332675

URL: http://llvm.org/viewvc/llvm-project?rev=332675&view=rev
Log:
Support: Add a raw_ostream::write_zeros() function. NFCI.

This will eventually replace MCObjectWriter::WriteZeros.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47033

Modified:
    llvm/trunk/include/llvm/Support/raw_ostream.h
    llvm/trunk/lib/Support/raw_ostream.cpp

Modified: llvm/trunk/include/llvm/Support/raw_ostream.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/raw_ostream.h?rev=332675&r1=332674&r2=332675&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/raw_ostream.h (original)
+++ llvm/trunk/include/llvm/Support/raw_ostream.h Thu May 17 15:11:43 2018
@@ -242,6 +242,9 @@ public:
   /// indent - Insert 'NumSpaces' spaces.
   raw_ostream &indent(unsigned NumSpaces);
 
+  /// write_zeros - Insert 'NumZeros' nulls.
+  raw_ostream &write_zeros(unsigned NumZeros);
+
   /// Changes the foreground color of text that will be output from this point
   /// forward.
   /// @param Color ANSI color to use, the special SAVEDCOLOR can be used to

Modified: llvm/trunk/lib/Support/raw_ostream.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/raw_ostream.cpp?rev=332675&r1=332674&r2=332675&view=diff
==============================================================================
--- llvm/trunk/lib/Support/raw_ostream.cpp (original)
+++ llvm/trunk/lib/Support/raw_ostream.cpp Thu May 17 15:11:43 2018
@@ -455,23 +455,35 @@ raw_ostream &raw_ostream::operator<<(con
   return *this;
 }
 
-/// indent - Insert 'NumSpaces' spaces.
-raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
-  static const char Spaces[] = "                                "
-                               "                                "
-                               "                ";
+template <char C>
+static raw_ostream &write_padding(raw_ostream &OS, unsigned NumChars) {
+  static const char Chars[] = {C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C,
+                               C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C,
+                               C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C,
+                               C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C,
+                               C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C};
 
   // Usually the indentation is small, handle it with a fastpath.
-  if (NumSpaces < array_lengthof(Spaces))
-    return write(Spaces, NumSpaces);
+  if (NumChars < array_lengthof(Chars))
+    return OS.write(Chars, NumChars);
 
-  while (NumSpaces) {
-    unsigned NumToWrite = std::min(NumSpaces,
-                                   (unsigned)array_lengthof(Spaces)-1);
-    write(Spaces, NumToWrite);
-    NumSpaces -= NumToWrite;
+  while (NumChars) {
+    unsigned NumToWrite = std::min(NumChars,
+                                   (unsigned)array_lengthof(Chars)-1);
+    OS.write(Chars, NumToWrite);
+    NumChars -= NumToWrite;
   }
-  return *this;
+  return OS;
+}
+
+/// indent - Insert 'NumSpaces' spaces.
+raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
+  return write_padding<' '>(*this, NumSpaces);
+}
+
+/// write_zeros - Insert 'NumZeros' nulls.
+raw_ostream &raw_ostream::write_zeros(unsigned NumZeros) {
+  return write_padding<'\0'>(*this, NumZeros);
 }
 
 void raw_ostream::anchor() {}