Make some methods const. The only interesting change here is that

it changes raw_fd_ostream::preferred_buffer_size to return zero on
a scary stat failure instead of setting the stream to an error state.
This method really should not mutate the stream.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91740 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/FormattedStream.h

@@ -59,7 +59,7 @@ namespace llvm
 
     /// current_pos - Return the current position within the stream,
     /// not counting the bytes currently in the buffer.
-    virtual uint64_t current_pos() { 
+    virtual uint64_t current_pos() const { 
       // This has the same effect as calling TheStream.current_pos(),
       // but that interface is private.
       return TheStream->tell() - TheStream->GetNumBytesInBuffer();

include/llvm/Support/raw_os_ostream.h

@@ -30,7 +30,7 @@ class raw_os_ostream : public raw_ostream {
   
   /// current_pos - Return the current position within the stream, not
   /// counting the bytes currently in the buffer.
-  virtual uint64_t current_pos();
+  virtual uint64_t current_pos() const;
   
 public:
   raw_os_ostream(std::ostream &O) : OS(O) {}

include/llvm/Support/raw_ostream.h

@@ -85,7 +85,7 @@ public:
   virtual ~raw_ostream();
 
   /// tell - Return the current offset with the file.
-  uint64_t tell() { return current_pos() + GetNumBytesInBuffer(); }
+  uint64_t tell() const { return current_pos() + GetNumBytesInBuffer(); }
 
   /// has_error - Return the value of the flag in this raw_ostream indicating
   /// whether an output error has been encountered.
@@ -116,7 +116,7 @@ public:
     SetBufferAndMode(new char[Size], Size, InternalBuffer);
   }
 
-  size_t GetBufferSize() {
+  size_t GetBufferSize() const {
     // If we're supposed to be buffered but haven't actually gotten around
     // to allocating the buffer yet, return the value that would be used.
     if (BufferMode != Unbuffered && OutBufStart == 0)
@@ -269,7 +269,7 @@ private:
 
   /// current_pos - Return the current position within the stream, not
   /// counting the bytes currently in the buffer.
-  virtual uint64_t current_pos() = 0;
+  virtual uint64_t current_pos() const = 0;
 
 protected:
   /// SetBuffer - Use the provided buffer as the raw_ostream buffer. This is
@@ -282,7 +282,7 @@ protected:
 
   /// preferred_buffer_size - Return an efficient buffer size for the
   /// underlying output mechanism.
-  virtual size_t preferred_buffer_size();
+  virtual size_t preferred_buffer_size() const;
 
   /// error_detected - Set the flag indicating that an output error has
   /// been encountered.
@@ -325,10 +325,10 @@ class raw_fd_ostream : public raw_ostream {
 
   /// current_pos - Return the current position within the stream, not
   /// counting the bytes currently in the buffer.
-  virtual uint64_t current_pos() { return pos; }
+  virtual uint64_t current_pos() const { return pos; }
 
   /// preferred_buffer_size - Determine an efficient buffer size.
-  virtual size_t preferred_buffer_size();
+  virtual size_t preferred_buffer_size() const;
 
 public:
 
@@ -423,7 +423,7 @@ class raw_string_ostream : public raw_ostream {
 
   /// current_pos - Return the current position within the stream, not
   /// counting the bytes currently in the buffer.
-  virtual uint64_t current_pos() { return OS.size(); }
+  virtual uint64_t current_pos() const { return OS.size(); }
 public:
   explicit raw_string_ostream(std::string &O) : OS(O) {}
   ~raw_string_ostream();
@@ -447,7 +447,7 @@ class raw_svector_ostream : public raw_ostream {
 
   /// current_pos - Return the current position within the stream, not
   /// counting the bytes currently in the buffer.
-  virtual uint64_t current_pos();
+  virtual uint64_t current_pos() const;
 public:
   /// Construct a new raw_svector_ostream.
   ///
@@ -468,7 +468,7 @@ class raw_null_ostream : public raw_ostream {
 
   /// current_pos - Return the current position within the stream, not
   /// counting the bytes currently in the buffer.
-  virtual uint64_t current_pos();
+  virtual uint64_t current_pos() const;
 
 public:
   explicit raw_null_ostream() {}

lib/Support/raw_os_ostream.cpp

@@ -27,4 +27,4 @@ void raw_os_ostream::write_impl(const char *Ptr, size_t Size) {
   OS.write(Ptr, Size);
 }
 
-uint64_t raw_os_ostream::current_pos() { return OS.tellp(); }
+uint64_t raw_os_ostream::current_pos() const { return OS.tellp(); }

lib/Support/raw_ostream.cpp

@@ -67,7 +67,7 @@ raw_ostream::~raw_ostream() {
 // An out of line virtual method to provide a home for the class vtable.
 void raw_ostream::handle() {}
 
-size_t raw_ostream::preferred_buffer_size() {
+size_t raw_ostream::preferred_buffer_size() const {
   // BUFSIZ is intended to be a reasonable default.
   return BUFSIZ;
 }
@@ -440,11 +440,13 @@ uint64_t raw_fd_ostream::seek(uint64_t off) {
   return pos;  
 }
 
-size_t raw_fd_ostream::preferred_buffer_size() {
+size_t raw_fd_ostream::preferred_buffer_size() const {
 #if !defined(_MSC_VER) && !defined(__MINGW32__) // Windows has no st_blksize.
   assert(FD >= 0 && "File not yet open!");
   struct stat statbuf;
-  if (fstat(FD, &statbuf) == 0) {
+  if (fstat(FD, &statbuf) != 0)
+    return 0;
+  
   // If this is a terminal, don't use buffering. Line buffering
   // would be a more traditional thing to do, but it's not worth
   // the complexity.
@@ -452,8 +454,6 @@ size_t raw_fd_ostream::preferred_buffer_size() {
     return 0;
   // Return the preferred block size.
   return statbuf.st_blksize;
-  }
-  error_detected();
 #endif
   return raw_ostream::preferred_buffer_size();
 }
@@ -578,7 +578,9 @@ void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
   SetBuffer(OS.end(), OS.capacity() - OS.size());
 }
 
-uint64_t raw_svector_ostream::current_pos() { return OS.size(); }
+uint64_t raw_svector_ostream::current_pos() const {
+   return OS.size();
+}
 
 StringRef raw_svector_ostream::str() {
   flush();
@@ -601,6 +603,6 @@ raw_null_ostream::~raw_null_ostream() {
 void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
 }
 
-uint64_t raw_null_ostream::current_pos() {
+uint64_t raw_null_ostream::current_pos() const {
   return 0;
 }