From e87b2abe91fc44bb9875188d80e3a43a9dfc41eb Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Wed, 15 Jul 2009 23:25:33 +0000 Subject: [PATCH] Change raw_ostream so that it doesn't call llvm_report_error immediately on every output error. Instead, add a flag to raw_ostream, and set the flag whenever an error is detected. The flag can be queried and cleared from the public API. This gives applications more flexibility to handling errors in application-specific ways. If the flag is not cleared when the raw_ostream is destructed, llvm_report_error is called from the destructor. This ensures that errors are not implicitly silenced, and provides convenient default behavior for tools like llc and opt. Clients wishing to avoid llvm_report_error calls from raw_ostream should check for errors and clear the error flag. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75857 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Support/raw_ostream.h | 39 ++++++++++++++++++++++++------ lib/Support/raw_ostream.cpp | 18 +++++++++++--- 2 files changed, 45 insertions(+), 12 deletions(-) diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h index 2cf9d22903b..367c35ca120 100644 --- a/include/llvm/Support/raw_ostream.h +++ b/include/llvm/Support/raw_ostream.h @@ -44,6 +44,10 @@ private: char *OutBufStart, *OutBufEnd, *OutBufCur; bool Unbuffered; + /// Error This flag is true if an error of any kind has been detected. + /// + bool Error; + public: // color order matches ANSI escape sequence, don't change enum Colors { @@ -58,18 +62,31 @@ public: SAVEDCOLOR }; - explicit raw_ostream(bool unbuffered=false) : Unbuffered(unbuffered) { + explicit raw_ostream(bool unbuffered=false) + : Unbuffered(unbuffered), Error(false) { // Start out ready to flush. OutBufStart = OutBufEnd = OutBufCur = 0; } - virtual ~raw_ostream() { - delete [] OutBufStart; - } + virtual ~raw_ostream(); /// tell - Return the current offset with the file. uint64_t tell() { return current_pos() + GetNumBytesInBuffer(); } + /// has_error - Return the value of the flag in this raw_ostream indicating + /// whether an output error has been encountered. + bool has_error() const { + return Error; + }; + + /// clear_error - Set the flag read by has_error() to false. If the error + /// flag is set at the time when this raw_ostream's destructor is called, + /// llvm_report_error is called to report the error. Use clear_error() + /// after handling the error to avoid this behavior. + void clear_error() { + Error = false; + }; + //===--------------------------------------------------------------------===// // Configuration Interface //===--------------------------------------------------------------------===// @@ -213,6 +230,11 @@ private: /// counting the bytes currently in the buffer. virtual uint64_t current_pos() = 0; +protected: + /// error_detected - Set the flag indicating that an output error has + /// been encountered. + void error_detected() { Error = true; } + //===--------------------------------------------------------------------===// // Private Interface //===--------------------------------------------------------------------===// @@ -311,8 +333,8 @@ raw_ostream &errs(); //===----------------------------------------------------------------------===// /// raw_os_ostream - A raw_ostream that writes to an std::ostream. This is a -/// simple adaptor class. It does not check for I/O errors; clients should use -/// the underlying stream to detect errors. +/// simple adaptor class. It does not check for output errors; clients should +/// use the underlying stream to detect errors. class raw_os_ostream : public raw_ostream { std::ostream &OS; @@ -332,7 +354,7 @@ public: }; /// raw_string_ostream - A raw_ostream that writes to an std::string. This is a -/// simple adaptor class. +/// simple adaptor class. This class does not encounter output errors. class raw_string_ostream : public raw_ostream { std::string &OS; @@ -358,7 +380,8 @@ public: }; /// raw_svector_ostream - A raw_ostream that writes to an SmallVector or -/// SmallString. This is a simple adaptor class. +/// SmallString. This is a simple adaptor class. This class does not +/// encounter output errors. class raw_svector_ostream : public raw_ostream { SmallVectorImpl &OS; diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp index b13d922b217..8724801818c 100644 --- a/lib/Support/raw_ostream.cpp +++ b/lib/Support/raw_ostream.cpp @@ -44,6 +44,16 @@ using namespace llvm; +raw_ostream::~raw_ostream() { + delete [] OutBufStart; + + // If there are any pending errors, report them now. Clients wishing + // to avoid llvm_report_error calls should check for errors with + // has_error() and clear the error flag with clear_error() before + // destructing raw_ostream objects which may have errors. + if (Error) + llvm_report_error("IO failure on output stream."); +} // An out of line virtual method to provide a home for the class vtable. void raw_ostream::handle() {} @@ -282,7 +292,7 @@ raw_fd_ostream::~raw_fd_ostream() { flush(); if (ShouldClose) if (::close(FD) != 0) - llvm_report_error("IO failure closing output stream."); + error_detected(); } } @@ -290,7 +300,7 @@ void raw_fd_ostream::write_impl(const char *Ptr, unsigned Size) { assert (FD >= 0 && "File already closed."); pos += Size; if (::write(FD, Ptr, Size) != (ssize_t) Size) - llvm_report_error("IO failure writing to output stream."); + error_detected(); } void raw_fd_ostream::close() { @@ -298,7 +308,7 @@ void raw_fd_ostream::close() { ShouldClose = false; flush(); if (::close(FD) != 0) - llvm_report_error("IO failure closing output stream."); + error_detected(); FD = -1; } @@ -306,7 +316,7 @@ uint64_t raw_fd_ostream::seek(uint64_t off) { flush(); pos = ::lseek(FD, off, SEEK_SET); if (pos != off) - llvm_report_error("IO failure seeking on output stream."); + error_detected(); return pos; }