| <html lang="en"> |
| <head> |
| <title>Analysis Options - GNU gprof</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="GNU gprof"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="Invoking.html#Invoking" title="Invoking"> |
| <link rel="prev" href="Output-Options.html#Output-Options" title="Output Options"> |
| <link rel="next" href="Miscellaneous-Options.html#Miscellaneous-Options" title="Miscellaneous Options"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the gprof profiler of the GNU system. |
| |
| Copyright (C) 1988, 1992, 1997, 1998, 1999, 2000, 2001, 2003, |
| 2007, 2008, 2009 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 |
| or any later version published by the Free Software Foundation; |
| with no Invariant Sections, with no Front-Cover Texts, and with no |
| Back-Cover Texts. A copy of the license is included in the |
| section entitled ``GNU Free Documentation License''. |
| |
| --> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Analysis-Options"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="Miscellaneous-Options.html#Miscellaneous-Options">Miscellaneous Options</a>, |
| Previous: <a rel="previous" accesskey="p" href="Output-Options.html#Output-Options">Output Options</a>, |
| Up: <a rel="up" accesskey="u" href="Invoking.html#Invoking">Invoking</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">4.2 Analysis Options</h3> |
| |
| <dl> |
| <dt><code>-a</code><dt><code>--no-static</code><dd>The ‘<samp><span class="samp">-a</span></samp>’ option causes <code>gprof</code> to suppress the printing of |
| statically declared (private) functions. (These are functions whose |
| names are not listed as global, and which are not visible outside the |
| file/function/block where they were defined.) Time spent in these |
| functions, calls to/from them, etc., will all be attributed to the |
| function that was loaded directly before it in the executable file. |
| <!-- This is compatible with Unix @code{gprof}, but a bad idea. --> |
| This option affects both the flat profile and the call graph. |
| |
| <br><dt><code>-c</code><dt><code>--static-call-graph</code><dd>The ‘<samp><span class="samp">-c</span></samp>’ option causes the call graph of the program to be |
| augmented by a heuristic which examines the text space of the object |
| file and identifies function calls in the binary machine code. |
| Since normal call graph records are only generated when functions are |
| entered, this option identifies children that could have been called, |
| but never were. Calls to functions that were not compiled with |
| profiling enabled are also identified, but only if symbol table |
| entries are present for them. |
| Calls to dynamic library routines are typically <em>not</em> found |
| by this option. |
| Parents or children identified via this heuristic |
| are indicated in the call graph with call counts of ‘<samp><span class="samp">0</span></samp>’. |
| |
| <br><dt><code>-D</code><dt><code>--ignore-non-functions</code><dd>The ‘<samp><span class="samp">-D</span></samp>’ option causes <code>gprof</code> to ignore symbols which |
| are not known to be functions. This option will give more accurate |
| profile data on systems where it is supported (Solaris and HPUX for |
| example). |
| |
| <br><dt><code>-k </code><var>from</var><code>/</code><var>to</var><dd>The ‘<samp><span class="samp">-k</span></samp>’ option allows you to delete from the call graph any arcs from |
| symbols matching symspec <var>from</var> to those matching symspec <var>to</var>. |
| |
| <br><dt><code>-l</code><dt><code>--line</code><dd>The ‘<samp><span class="samp">-l</span></samp>’ option enables line-by-line profiling, which causes |
| histogram hits to be charged to individual source code lines, |
| instead of functions. This feature only works with programs compiled |
| by older versions of the <code>gcc</code> compiler. Newer versions of |
| <code>gcc</code> are designed to work with the <code>gcov</code> tool instead. |
| |
| <p>If the program was compiled with basic-block counting enabled, |
| this option will also identify how many times each line of |
| code was executed. |
| While line-by-line profiling can help isolate where in a large function |
| a program is spending its time, it also significantly increases |
| the running time of <code>gprof</code>, and magnifies statistical |
| inaccuracies. |
| See <a href="Sampling-Error.html#Sampling-Error">Statistical Sampling Error</a>. |
| |
| <br><dt><code>-m </code><var>num</var><dt><code>--min-count=</code><var>num</var><dd>This option affects execution count output only. |
| Symbols that are executed less than <var>num</var> times are suppressed. |
| |
| <br><dt><code>-n</code><var>symspec</var><dt><code>--time=</code><var>symspec</var><dd>The ‘<samp><span class="samp">-n</span></samp>’ option causes <code>gprof</code>, in its call graph analysis, |
| to only propagate times for symbols matching <var>symspec</var>. |
| |
| <br><dt><code>-N</code><var>symspec</var><dt><code>--no-time=</code><var>symspec</var><dd>The ‘<samp><span class="samp">-n</span></samp>’ option causes <code>gprof</code>, in its call graph analysis, |
| not to propagate times for symbols matching <var>symspec</var>. |
| |
| <br><dt><code>-S</code><var>filename</var><dt><code>--external-symbol-table=</code><var>filename</var><dd>The ‘<samp><span class="samp">-S</span></samp>’ option causes <code>gprof</code> to read an external symbol table |
| file, such as <samp><span class="file">/proc/kallsyms</span></samp>, rather than read the symbol table |
| from the given object file (the default is <code>a.out</code>). This is useful |
| for profiling kernel modules. |
| |
| <br><dt><code>-z</code><dt><code>--display-unused-functions</code><dd>If you give the ‘<samp><span class="samp">-z</span></samp>’ option, <code>gprof</code> will mention all |
| functions in the flat profile, even those that were never called, and |
| that had no time spent in them. This is useful in conjunction with the |
| ‘<samp><span class="samp">-c</span></samp>’ option for discovering which routines were never called. |
| |
| </dl> |
| |
| </body></html> |
| |
