Rather than giving SmallPtrSetImpl a member field SmallArray which is magically

[oota-llvm.git] / lib / Support / FormattedStream.cpp

diff --git a/lib/Support/FormattedStream.cpp b/lib/Support/FormattedStream.cpp
index 867e5de4d1295608cd2162da188fb8f5eddb3ee1..c72b5a1751b4097bf6c74a3411b3b01bf9cc3f6d 100644 (file)
--- a/lib/Support/FormattedStream.cpp
+++ b/lib/Support/FormattedStream.cpp
@@ -11,61 +11,71 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/FormattedStream.h"
 
 using namespace llvm;
 
-/// ComputeColumn - Examine the current output and figure out which
+/// CountColumns - Examine the given char sequence and figure out which
 /// column we end up in after output.
 ///
-void formatted_raw_ostream::ComputeColumn() {
+static unsigned CountColumns(unsigned Column, const char *Ptr, size_t Size) {
   // Keep track of the current column by scanning the string for
   // special characters
 
-  // The buffer may have been allocated underneath us.
-  if (Scanned == 0 && GetNumBytesInBuffer() != 0) {
-    Scanned = begin();
-  }
-
-  while (Scanned != end()) {
-    ++ColumnScanned;
-    if (*Scanned == '\n' || *Scanned == '\r')
-      ColumnScanned = 0;
-    else if (*Scanned == '\t')
+  for (const char *End = Ptr + Size; Ptr != End; ++Ptr) {
+    ++Column;
+    if (*Ptr == '\n' || *Ptr == '\r')
+      Column = 0;
+    else if (*Ptr == '\t')
       // Assumes tab stop = 8 characters.
-      ColumnScanned += (8 - (ColumnScanned & 0x7)) & 0x7;
-    ++Scanned;
+      Column += (8 - (Column & 0x7)) & 0x7;
   }
+
+  return Column;
+}
+
+/// ComputeColumn - Examine the current output and figure out which
+/// column we end up in after output.
+void formatted_raw_ostream::ComputeColumn(const char *Ptr, size_t Size) {
+  // If our previous scan pointer is inside the buffer, assume we already
+  // scanned those bytes. This depends on raw_ostream to not change our buffer
+  // in unexpected ways.
+  if (Ptr <= Scanned && Scanned <= Ptr + Size) {
+    // Scan all characters added since our last scan to determine the new
+    // column.
+    ColumnScanned = CountColumns(ColumnScanned, Scanned, 
+                                 Size - (Scanned - Ptr));
+  } else
+    ColumnScanned = CountColumns(ColumnScanned, Ptr, Size);
+
+  // Update the scanning pointer.
+  Scanned = Ptr + Size;
 }
 
 /// PadToColumn - Align the output to some column number.
 ///
 /// \param NewCol - The column to move to.
-/// \param MinPad - The minimum space to give after the most recent
-/// I/O, even if the current column + minpad > newcol.
 ///
-void formatted_raw_ostream::PadToColumn(unsigned NewCol, unsigned MinPad) { 
+formatted_raw_ostream &formatted_raw_ostream::PadToColumn(unsigned NewCol) { 
   // Figure out what's in the buffer and add it to the column count.
-  ComputeColumn();
+  ComputeColumn(getBufferStart(), GetNumBytesInBuffer());
 
   // Output spaces until we reach the desired column.
-  unsigned num = NewCol - ColumnScanned;
-  if (NewCol < ColumnScanned || num < MinPad)
-    num = MinPad;
-
-  // Keep a buffer of spaces handy to speed up processing.
-  const char *Spaces = "                                                      "
-    "                                                                         ";
-
-  assert(num < MAX_COLUMN_PAD && "Unexpectedly large column padding");
-
-  write(Spaces, num);
+  indent(std::max(int(NewCol - ColumnScanned), 1));
+  return *this;
 }
 
 void formatted_raw_ostream::write_impl(const char *Ptr, size_t Size) {
-  ComputeColumn();
+  // Figure out what's in the buffer and add it to the column count.
+  ComputeColumn(Ptr, Size);
+
+  // Write the data to the underlying stream (which is unbuffered, so
+  // the data will be immediately written out).
   TheStream->write(Ptr, Size);
-  Scanned = begin();
+
+  // Reset the scanning pointer.
+  Scanned = 0;
 }
 
 /// fouts() - This returns a reference to a formatted_raw_ostream for
@@ -81,3 +91,10 @@ formatted_raw_ostream &llvm::ferrs() {
   static formatted_raw_ostream S(errs());
   return S;
 }
+
+/// fdbgs() - This returns a reference to a formatted_raw_ostream for
+/// the debug stream.  Use it like: fdbgs() << "foo" << "bar";
+formatted_raw_ostream &llvm::fdbgs() {
+  static formatted_raw_ostream S(dbgs());
+  return S;
+}