term% cat index.txt CALLS(1) General Commands Manual CALLS(1)
NAME
calls - print static call graph of a C program
SYNOPSIS
calls [ -ptv ] [ -f function ] [ -w width ... ] [ -D def ] [ -U def ]
[ -I dir ] [ file ... ]
DESCRIPTION
Calls reads files, which should be the source of C programs, and writes
the analysed calling pattern to standard output. If no file names are
given, standard input will be read. Calls is intended to help analyse
the flow of a program by laying out the functions called in the hierar‐
chical manner used in Software Tools by B. Kernighan and P. Plauger.
All input is first filtered through cpp(1). Functions called but not
defined within the source files are shown as:
function [external]
Recursive references are shown as:
<<< function
Options are:
-f Add function as a root of a call graph to be printed.
-p Make cpp search the APE include directories.
-t Provides a terse form of output, in which the calling pattern for
any function is printed only once on the first occurrence of the
function. Subsequent occurrences output the function name and a
notation
... [see line xx]
This is the default case.
-v Full output of function calling patterns on every occurrence.
-wn Set the output width to n. The default is 80 columns.
-Dname
-Dname=defn
Define the name for cpp, as if by #define. If no definition is
given, the name is defined as 1.
-Uname
Remove any initial definition of name, where name is a reserved
symbol that is predefined by cpp.
-Idir Change the algorithm for searching for #include files whose names
do not begin with / to look in dir before looking in the directo‐
ries on the standard list.
EXAMPLES
What does cat call?
% calls -f main /sys/src/cmd/cat.c
1 main
2 cat
3 read [external]
4 write [external]
5 sysfatal [external]
6 open [external]
7 sysfatal [external]
8 close [external]
9 exits [external]
What internal functions does dd call?
% calls -f main /sys/src/cmd/dd.c | grep -v '\[external\]'
1 main
5 number
6 <<< number
9 match
17 flsh
21 term
22 stats
25 term ... [see line 21]
26 stats ... [see line 22]
Note the recursion in number.
Generate the PC kernel's internal call graph.
cd /sys/src/9/pc
calls -f main -I../port -I. ../port/*.c ../ip/*.c *.c |
grep -v external
BUGS
Forward declared functions defined within a function body which are not
subsequently used within that function body will be listed as having
been called.
Does not understand calls through function pointers.
Does not understand the restricted scope of static functions.
CALLS(1)