balst_stacktraceprintutil.h

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/// @file balst_stacktraceprintutil.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// balst_stacktraceprintutil.h                                        -*-C++-*-
#ifndef INCLUDED_BALST_STACKTRACEPRINTUTIL
#define INCLUDED_BALST_STACKTRACEPRINTUTIL
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup balst_stacktraceprintutil balst_stacktraceprintutil
/// @brief  Provide a single function to perform and print a stack trace.
/// @addtogroup bal
/// @{
/// @addtogroup balst
/// @{
/// @addtogroup balst_stacktraceprintutil
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#balst_stacktraceprintutil-purpose"> Purpose</a>
/// * <a href="#balst_stacktraceprintutil-classes"> Classes </a>
/// * <a href="#balst_stacktraceprintutil-description"> Description </a>
///   * <a href="#balst_stacktraceprintutil-logexceptionstacktrace"> logExceptionStackTrace </a>
///   * <a href="#balst_stacktraceprintutil-usage"> Usage </a>
///     * <a href="#balst_stacktraceprintutil-example-1-printing-a-stack-trace"> Example 1: Printing a Stack Trace </a>
///
/// # Purpose {#balst_stacktraceprintutil-purpose}
/// Provide a single function to perform and print a stack trace.
///
/// # Classes {#balst_stacktraceprintutil-classes}
///
/// -  balst::StackTracePrintUtil: namespace for functions to print a stack trace
///
/// @see  balst_stacktraceutil
///
/// # Description {#balst_stacktraceprintutil-description}
/// This component defines a namespace `struct`,
/// `balst::StackTracePrintUtil`, containing static platform-independent
/// functions that will perform a stack trace and print it to a supplied stream.
/// Not all properties of a stack trace are printed on all platforms because the
/// set of properties describing a stack trace that are obtainable varies
/// according to both the platform and build parameters.  For example, on
/// Solaris, source file names and line numbers are not provided.  Function
/// names and addresses are provided on all platforms.  The `printStackTrace`
/// function always prints a description of the stack of the calling thread.
///
/// ## logExceptionStackTrace {#balst_stacktraceprintutil-logexceptionstacktrace}
///
///
/// The function `StackTracePrintUtil::logExceptionStackTrace` is meant to be
/// passed as a function pointer to the `bslstl::StdExceptUtil::set*Hook`
/// functions and will result in a stack trace being logged with fatal severity
/// prior to the respective exception being thrown.  It is a substitute for the
/// function `bslstl::StdExceptUtil::logCheapStackTrace` that takes longer to
/// run but provides far superior output.
///
/// ## Usage {#balst_stacktraceprintutil-usage}
///
///
/// This section illustrates intended use of this component.
///
/// ### Example 1: Printing a Stack Trace {#balst_stacktraceprintutil-example-1-printing-a-stack-trace}
///
///
/// This example shows how to obtain a stack trace and print it to a stream, all
/// by calling just the static function
/// `balst::StackTracePrintUtil::printStackTrace`.
///
/// First, we define a recursive function `recurseAndPrintStack` that recurses
/// to the specified `depth`, then calls
/// `balst::StackTracePrintUtil::printStackTrace` to obtain a stack trace and
/// print it to `cout`.  When we call `printStackTrace`, neither of the optional
/// arguments corresponding to `maxFrames` or `demanglingPreferredFlag` are
/// supplied; `maxFrames` defaults to at least 1024 (which is more than we
/// need), and `demanglingPreferredFlag` defaults to `true`.
/// @code
/// static
/// void recurseAndPrintStack(int *depth)
///     // Recurse to the specified 'depth', then print out the stack trace to
///     // 'cout'.
/// {
///     if (--*depth > 0) {
///         recurseAndPrintStack(depth);
///     }
///     else {
///         balst::StackTracePrintUtil::printStackTrace(cout);
///     }
///
///     ++*depth;   // Prevent compiler from optimizing tail recursion as a
///                 // loop.
/// }
/// @endcode
/// Then, we call `recurseAndPrintStack` from the main program.
/// @code
/// int main()
/// {
///     int depth = 5;
///     recurseAndPrintStack(&depth);
///     assert(5 == depth);
/// }
/// @endcode
/// Now, invoking the main program on AIX produces the following output:
/// @code
/// (0): BloombergLP::balst::StackTracePrintUtil::.printStackTrace(
///      std::basic_ostream<char,std::char_traits<char> >&,int,bool)+0x170 at
///      0x1000a2c8 source:balst_stacktraceprintutil.cpp:52 in
///      balst_stacktraceprintutil.t.dbg_
/// (1): .recurseAndPrintStack(int*)+0x58 at 0x1000a118
///      source:balst_stacktraceprintutil.t.cpp:652 in
///      balst_stacktraceprintutil.t.dbg_
/// (2): .recurseAndPrintStack(int*)+0x40 at 0x1000a100
///      source:balst_stacktraceprintutil.t.cpp:650
///      in balst_stacktraceprintutil.t.dbg_
/// (3): .recurseAndPrintStack(int*)+0x40 at 0x1000a100
///      source:balst_stacktraceprintutil.t.cpp:650 in
///      balst_stacktraceprintutil.t.dbg_
/// (4): .recurseAndPrintStack(int*)+0x40 at 0x1000a100
///      source:balst_stacktraceprintutil.t.cpp:650 in
///      balst_stacktraceprintutil.t.dbg_
/// (5): .recurseAndPrintStack(int*)+0x40 at 0x1000a100
///      source:balst_stacktraceprintutil.t.cpp:650 in
///      balst_stacktraceprintutil.t.dbg_
/// (6): .main+0x2f4 at 0x10000a4c source:balst_stacktraceprintutil.t.cpp:724
///      in balst_stacktraceprintutil.t.dbg_
/// (7): .__start+0x6c at 0x1000020c source:crt0main.s in
///      balst_stacktraceprintutil.t.dbg_
/// @endcode
/// Finally, we observe the following about the above output to `cout`.  Notice
/// that since the actual output would write each stack trace frame all on a
/// single line, and all the lines here were longer than 80 characters, it has
/// been manually edited to wrap and have every line be less than 80 columns.
/// Also note the program name is truncated to 32 characters in length.
/// @}
/** @} */
/** @} */
 
/** @addtogroup bal
 * @{
 */
/** @addtogroup balst
 * @{
 */
/** @addtogroup balst_stacktraceprintutil
 * @{
 */
 
#include <balscm_version.h>
 
#include <bslma_allocator.h>
#include <bslma_defaultallocatorguard.h>
 
#include <bsl_iosfwd.h>
#include <bsl_sstream.h>
#include <bsl_string.h>
 
 
 
namespace balst {
                         // =========================
                         // class StackTracePrintUtil
                         // =========================
 
/// This `struct` serves as a namespace for static methods that perform and
/// print a description of a stack trace.
struct StackTracePrintUtil {
 
    // CLASS METHODS
 
    /// Obtain a trace of the stack and print it to the specified `stream`.
    /// Optionally specify `maxFrames` indicating the maximum number of
    /// frames from the top of the stack that will be printed.  If
    /// `maxFrames` is not specified, a value of at least 1024 is used.
    /// Optionally specify `demanglingPreferredFlag`, indicating a
    /// preference whether to attempt to demangle function names.  If
    /// `damanglingPreferredFlag` is not specified, an attempt to demangle
    /// is assumed.  If an error occurs, a single-line error message is
    /// printed to `stream`.  Optionally specify `additionalIgnoreFrames`
    /// which is added to `bsls::StackAddressUtil::k_IGNORE_FRAMES` to
    /// ignore frames of the caller.  Return a reference to 'stream.  The
    /// behavior is undefined unless `-1 <= maxFrames` and
    /// `0 <= additionalIgnoreFrames`.  Note that attempting to demangle
    /// symbol names could involve calling `malloc`, and that symbol names
    /// are always demangled on the Windows platform.
    static bsl::ostream& printStackTrace(
                                 bsl::ostream& stream,
                                 int           maxFrames = -1,
                                 bool          demanglingPreferredFlag = true,
                                 int           additionalIgnoreFrames = 0);
 
    /// Log a message using `BSLS_LOG` consisting of "About to throw
    /// <exceptionName>.  <message>" followed by a stack trace.  This
    /// function is to be set as an exception "pre throw hook" for the
    /// component @ref bslstl_stdexceptutil .  If this funciton is set as the
    /// pre throw hook, it will be called prior to exceptions being thrown,
    /// Note that this function requires considerable disk access and is
    /// therefore slow, so it should not be used for frequently-occurring
    /// exceptions that are expected to be caught and recovered from.
    static void logExceptionStackTrace(const char *exceptionName,
                                       const char *message);
};
 
                       // ==============================
                       // class StackTracePrintUtil_Test
                       // ==============================
 
/// This `struct` is not intended for use by clients of this component; it
/// exists only for testing purposes.
struct StackTracePrintUtil_Test {
 
    // CLASS METHODS
 
    /// Obtain a stack trace and assign a description of the stack to the
    /// specified `string`.  Note that this method is for testing only, and
    /// must be declared inline in an include file in order to test source
    /// file name resolution of a routine in an include file.
    static void printStackTraceToString(bsl::string *string);
};
 
// ============================================================================
//                        INLINE FUNCTION DEFINITIONS
// ============================================================================
 
                      // -------------------------------
                      // struct StackTracePrintUtil_Test
                      // -------------------------------
 
// CLASS METHOD
inline
void StackTracePrintUtil_Test::printStackTraceToString(bsl::string *string)
{
    bslma::Allocator *a = string->get_allocator().mechanism();
    bslma::DefaultAllocatorGuard guard(a);
 
    bsl::ostringstream os;
    StackTracePrintUtil::printStackTrace(os);
    *string = os.str();
}
 
}  // close package namespace
 
 
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2015 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------
 
/** @} */
/** @} */
/** @} */