diff options
Diffstat (limited to 'contrib/gcc/doc/gcov.1')
| -rw-r--r-- | contrib/gcc/doc/gcov.1 | 453 |
1 files changed, 0 insertions, 453 deletions
diff --git a/contrib/gcc/doc/gcov.1 b/contrib/gcc/doc/gcov.1 deleted file mode 100644 index 44d1e33c8b74..000000000000 --- a/contrib/gcc/doc/gcov.1 +++ /dev/null @@ -1,453 +0,0 @@ -.\" Automatically generated by Pod::Man version 1.15 -.\" Wed Feb 5 03:13:55 2003 -.\" -.\" Standard preamble: -.\" ====================================================================== -.de Sh \" Subsection heading -.br -.if t .Sp -.ne 5 -.PP -\fB\\$1\fR -.PP -.. -.de Sp \" Vertical space (when we can't use .PP) -.if t .sp .5v -.if n .sp -.. -.de Ip \" List item -.br -.ie \\n(.$>=3 .ne \\$3 -.el .ne 3 -.IP "\\$1" \\$2 -.. -.de Vb \" Begin verbatim text -.ft CW -.nf -.ne \\$1 -.. -.de Ve \" End verbatim text -.ft R - -.fi -.. -.\" Set up some character translations and predefined strings. \*(-- will -.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left -.\" double quote, and \*(R" will give a right double quote. | will give a -.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used -.\" to do unbreakable dashes and therefore won't be available. \*(C` and -.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<> -.tr \(*W-|\(bv\*(Tr -.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' -.ie n \{\ -. ds -- \(*W- -. ds PI pi -. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch -. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch -. ds L" "" -. ds R" "" -. ds C` "" -. ds C' "" -'br\} -.el\{\ -. ds -- \|\(em\| -. ds PI \(*p -. ds L" `` -. ds R" '' -'br\} -.\" -.\" If the F register is turned on, we'll generate index entries on stderr -.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and -.\" index entries marked with X<> in POD. Of course, you'll have to process -.\" the output yourself in some meaningful fashion. -.if \nF \{\ -. de IX -. tm Index:\\$1\t\\n%\t"\\$2" -.. -. nr % 0 -. rr F -.\} -.\" -.\" For nroff, turn off justification. Always turn off hyphenation; it -.\" makes way too many mistakes in technical documents. -.hy 0 -.if n .na -.\" -.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). -.\" Fear. Run. Save yourself. No user-serviceable parts. -.bd B 3 -. \" fudge factors for nroff and troff -.if n \{\ -. ds #H 0 -. ds #V .8m -. ds #F .3m -. ds #[ \f1 -. ds #] \fP -.\} -.if t \{\ -. ds #H ((1u-(\\\\n(.fu%2u))*.13m) -. ds #V .6m -. ds #F 0 -. ds #[ \& -. ds #] \& -.\} -. \" simple accents for nroff and troff -.if n \{\ -. ds ' \& -. ds ` \& -. ds ^ \& -. ds , \& -. ds ~ ~ -. ds / -.\} -.if t \{\ -. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" -. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' -. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' -. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' -. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' -. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' -.\} -. \" troff and (daisy-wheel) nroff accents -.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' -.ds 8 \h'\*(#H'\(*b\h'-\*(#H' -.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] -.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' -.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' -.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] -.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] -.ds ae a\h'-(\w'a'u*4/10)'e -.ds Ae A\h'-(\w'A'u*4/10)'E -. \" corrections for vroff -.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' -.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' -. \" for low resolution devices (crt and lpr) -.if \n(.H>23 .if \n(.V>19 \ -\{\ -. ds : e -. ds 8 ss -. ds o a -. ds d- d\h'-1'\(ga -. ds D- D\h'-1'\(hy -. ds th \o'bp' -. ds Th \o'LP' -. ds ae ae -. ds Ae AE -.\} -.rm #[ #] #H #V #F C -.\" ====================================================================== -.\" -.IX Title "GCOV 1" -.TH GCOV 1 "gcc-3.2.2" "2003-02-05" "GNU" -.UC -.SH "NAME" -gcov \- coverage testing tool -.SH "SYNOPSIS" -.IX Header "SYNOPSIS" -gcov [\fB\-v\fR|\fB\*(--version\fR] [\fB\-h\fR|\fB\*(--help\fR] - [\fB\-b\fR|\fB\*(--branch-probabilities\fR] [\fB\-c\fR|\fB\*(--branch-counts\fR] - [\fB\-n\fR|\fB\*(--no-output\fR] [\fB\-l\fR|\fB\*(--long-file-names\fR] - [\fB\-f\fR|\fB\*(--function-summaries\fR] - [\fB\-o\fR|\fB\*(--object-directory\fR \fIdirectory\fR] \fIsourcefile\fR -.SH "DESCRIPTION" -.IX Header "DESCRIPTION" -\&\fBgcov\fR is a test coverage program. Use it in concert with \s-1GCC\s0 -to analyze your programs to help create more efficient, faster -running code. You can use \fBgcov\fR as a profiling tool to help -discover where your optimization efforts will best affect your code. You -can also use \fBgcov\fR along with the other profiling tool, -\&\fBgprof\fR, to assess which parts of your code use the greatest amount -of computing time. -.PP -Profiling tools help you analyze your code's performance. Using a -profiler such as \fBgcov\fR or \fBgprof\fR, you can find out some -basic performance statistics, such as: -.Ip "\(bu" 4 -how often each line of code executes -.Ip "\(bu" 4 -what lines of code are actually executed -.Ip "\(bu" 4 -how much computing time each section of code uses -.PP -Once you know these things about how your code works when compiled, you -can look at each module to see which modules should be optimized. -\&\fBgcov\fR helps you determine where to work on optimization. -.PP -Software developers also use coverage testing in concert with -testsuites, to make sure software is actually good enough for a release. -Testsuites can verify that a program works as expected; a coverage -program tests to see how much of the program is exercised by the -testsuite. Developers can then determine what kinds of test cases need -to be added to the testsuites to create both better testing and a better -final product. -.PP -You should compile your code without optimization if you plan to use -\&\fBgcov\fR because the optimization, by combining some lines of code -into one function, may not give you as much information as you need to -look for `hot spots' where the code is using a great deal of computer -time. Likewise, because \fBgcov\fR accumulates statistics by line (at -the lowest resolution), it works best with a programming style that -places only one statement on each line. If you use complicated macros -that expand to loops or to other control structures, the statistics are -less helpful\-\-\-they only report on the line where the macro call -appears. If your complex macros behave like functions, you can replace -them with inline functions to solve this problem. -.PP -\&\fBgcov\fR creates a logfile called \fI\fIsourcefile\fI.gcov\fR which -indicates how many times each line of a source file \fI\fIsourcefile\fI.c\fR -has executed. You can use these logfiles along with \fBgprof\fR to aid -in fine-tuning the performance of your programs. \fBgprof\fR gives -timing information you can use along with the information you get from -\&\fBgcov\fR. -.PP -\&\fBgcov\fR works only on code compiled with \s-1GCC\s0. It is not -compatible with any other profiling or test coverage mechanism. -.SH "OPTIONS" -.IX Header "OPTIONS" -.Ip "\fB\-h\fR" 4 -.IX Item "-h" -.PD 0 -.Ip "\fB\*(--help\fR" 4 -.IX Item "help" -.PD -Display help about using \fBgcov\fR (on the standard output), and -exit without doing any further processing. -.Ip "\fB\-v\fR" 4 -.IX Item "-v" -.PD 0 -.Ip "\fB\*(--version\fR" 4 -.IX Item "version" -.PD -Display the \fBgcov\fR version number (on the standard output), -and exit without doing any further processing. -.Ip "\fB\-b\fR" 4 -.IX Item "-b" -.PD 0 -.Ip "\fB\*(--branch-probabilities\fR" 4 -.IX Item "branch-probabilities" -.PD -Write branch frequencies to the output file, and write branch summary -info to the standard output. This option allows you to see how often -each branch in your program was taken. -.Ip "\fB\-c\fR" 4 -.IX Item "-c" -.PD 0 -.Ip "\fB\*(--branch-counts\fR" 4 -.IX Item "branch-counts" -.PD -Write branch frequencies as the number of branches taken, rather than -the percentage of branches taken. -.Ip "\fB\-n\fR" 4 -.IX Item "-n" -.PD 0 -.Ip "\fB\*(--no-output\fR" 4 -.IX Item "no-output" -.PD -Do not create the \fBgcov\fR output file. -.Ip "\fB\-l\fR" 4 -.IX Item "-l" -.PD 0 -.Ip "\fB\*(--long-file-names\fR" 4 -.IX Item "long-file-names" -.PD -Create long file names for included source files. For example, if the -header file \fIx.h\fR contains code, and was included in the file -\&\fIa.c\fR, then running \fBgcov\fR on the file \fIa.c\fR will produce -an output file called \fIa.c.x.h.gcov\fR instead of \fIx.h.gcov\fR. -This can be useful if \fIx.h\fR is included in multiple source files. -.Ip "\fB\-f\fR" 4 -.IX Item "-f" -.PD 0 -.Ip "\fB\*(--function-summaries\fR" 4 -.IX Item "function-summaries" -.PD -Output summaries for each function in addition to the file level summary. -.Ip "\fB\-o\fR \fIdirectory\fR" 4 -.IX Item "-o directory" -.PD 0 -.Ip "\fB\*(--object-directory\fR \fIdirectory\fR" 4 -.IX Item "object-directory directory" -.PD -The directory where the object files live. Gcov will search for \fI.bb\fR, -\&\fI.bbg\fR, and \fI.da\fR files in this directory. -.PP -When using \fBgcov\fR, you must first compile your program with two -special \s-1GCC\s0 options: \fB\-fprofile-arcs \-ftest-coverage\fR. -This tells the compiler to generate additional information needed by -gcov (basically a flow graph of the program) and also includes -additional code in the object files for generating the extra profiling -information needed by gcov. These additional files are placed in the -directory where the source code is located. -.PP -Running the program will cause profile output to be generated. For each -source file compiled with \fB\-fprofile-arcs\fR, an accompanying \fI.da\fR -file will be placed in the source directory. -.PP -Running \fBgcov\fR with your program's source file names as arguments -will now produce a listing of the code along with frequency of execution -for each line. For example, if your program is called \fItmp.c\fR, this -is what you see when you use the basic \fBgcov\fR facility: -.PP -.Vb 5 -\& $ gcc -fprofile-arcs -ftest-coverage tmp.c -\& $ a.out -\& $ gcov tmp.c -\& 87.50% of 8 source lines executed in file tmp.c -\& Creating tmp.c.gcov. -.Ve -The file \fItmp.c.gcov\fR contains output from \fBgcov\fR. -Here is a sample: -.PP -.Vb 3 -\& main() -\& { -\& 1 int i, total; -.Ve -.Vb 1 -\& 1 total = 0; -.Ve -.Vb 2 -\& 11 for (i = 0; i < 10; i++) -\& 10 total += i; -.Ve -.Vb 5 -\& 1 if (total != 45) -\& ###### printf ("Failure\en"); -\& else -\& 1 printf ("Success\en"); -\& 1 } -.Ve -When you use the \fB\-b\fR option, your output looks like this: -.PP -.Vb 6 -\& $ gcov -b tmp.c -\& 87.50% of 8 source lines executed in file tmp.c -\& 80.00% of 5 branches executed in file tmp.c -\& 80.00% of 5 branches taken at least once in file tmp.c -\& 50.00% of 2 calls executed in file tmp.c -\& Creating tmp.c.gcov. -.Ve -Here is a sample of a resulting \fItmp.c.gcov\fR file: -.PP -.Vb 3 -\& main() -\& { -\& 1 int i, total; -.Ve -.Vb 1 -\& 1 total = 0; -.Ve -.Vb 5 -\& 11 for (i = 0; i < 10; i++) -\& branch 0 taken = 91% -\& branch 1 taken = 100% -\& branch 2 taken = 100% -\& 10 total += i; -.Ve -.Vb 9 -\& 1 if (total != 45) -\& branch 0 taken = 100% -\& ###### printf ("Failure\en"); -\& call 0 never executed -\& branch 1 never executed -\& else -\& 1 printf ("Success\en"); -\& call 0 returns = 100% -\& 1 } -.Ve -For each basic block, a line is printed after the last line of the basic -block describing the branch or call that ends the basic block. There can -be multiple branches and calls listed for a single source line if there -are multiple basic blocks that end on that line. In this case, the -branches and calls are each given a number. There is no simple way to map -these branches and calls back to source constructs. In general, though, -the lowest numbered branch or call will correspond to the leftmost construct -on the source line. -.PP -For a branch, if it was executed at least once, then a percentage -indicating the number of times the branch was taken divided by the -number of times the branch was executed will be printed. Otherwise, the -message ``never executed'' is printed. -.PP -For a call, if it was executed at least once, then a percentage -indicating the number of times the call returned divided by the number -of times the call was executed will be printed. This will usually be -100%, but may be less for functions call \f(CW\*(C`exit\*(C'\fR or \f(CW\*(C`longjmp\*(C'\fR, -and thus may not return every time they are called. -.PP -The execution counts are cumulative. If the example program were -executed again without removing the \fI.da\fR file, the count for the -number of times each line in the source was executed would be added to -the results of the previous \fIrun\fR\|(s). This is potentially useful in -several ways. For example, it could be used to accumulate data over a -number of program runs as part of a test verification suite, or to -provide more accurate long-term information over a large number of -program runs. -.PP -The data in the \fI.da\fR files is saved immediately before the program -exits. For each source file compiled with \fB\-fprofile-arcs\fR, the profiling -code first attempts to read in an existing \fI.da\fR file; if the file -doesn't match the executable (differing number of basic block counts) it -will ignore the contents of the file. It then adds in the new execution -counts and finally writes the data to the file. -.Sh "Using \fBgcov\fP with \s-1GCC\s0 Optimization" -.IX Subsection "Using gcov with GCC Optimization" -If you plan to use \fBgcov\fR to help optimize your code, you must -first compile your program with two special \s-1GCC\s0 options: -\&\fB\-fprofile-arcs \-ftest-coverage\fR. Aside from that, you can use any -other \s-1GCC\s0 options; but if you want to prove that every single line -in your program was executed, you should not compile with optimization -at the same time. On some machines the optimizer can eliminate some -simple code lines by combining them with other lines. For example, code -like this: -.PP -.Vb 4 -\& if (a != b) -\& c = 1; -\& else -\& c = 0; -.Ve -can be compiled into one instruction on some machines. In this case, -there is no way for \fBgcov\fR to calculate separate execution counts -for each line because there isn't separate code for each line. Hence -the \fBgcov\fR output looks like this if you compiled the program with -optimization: -.PP -.Vb 4 -\& 100 if (a != b) -\& 100 c = 1; -\& 100 else -\& 100 c = 0; -.Ve -The output shows that this block of code, combined by optimization, -executed 100 times. In one sense this result is correct, because there -was only one instruction representing all four of these lines. However, -the output does not indicate how many times the result was 0 and how -many times the result was 1. -.SH "SEE ALSO" -.IX Header "SEE ALSO" -\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf-funding\fR\|(7), \fIgcc\fR\|(1) and the Info entry for \fIgcc\fR. -.SH "COPYRIGHT" -.IX Header "COPYRIGHT" -Copyright (c) 1996, 1997, 1999, 2000, 2001 Free Software Foundation, Inc. -.PP -Permission is granted to copy, distribute and/or modify this document -under the terms of the \s-1GNU\s0 Free Documentation License, Version 1.1 or -any later version published by the Free Software Foundation; with the -Invariant Sections being ``\s-1GNU\s0 General Public License'' and ``Funding -Free Software'', the Front-Cover texts being (a) (see below), and with -the Back-Cover Texts being (b) (see below). A copy of the license is -included in the \fIgfdl\fR\|(7) man page. -.PP -(a) The \s-1FSF\s0's Front-Cover Text is: -.PP -.Vb 1 -\& A GNU Manual -.Ve -(b) The \s-1FSF\s0's Back-Cover Text is: -.PP -.Vb 3 -\& You have freedom to copy and modify this GNU Manual, like GNU -\& software. Copies published by the Free Software Foundation raise -\& funds for GNU development. -.Ve |