CALLS(1) 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 hierarchical 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 occur-
rences 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 def-
inition is given, the name is defined as 1.
-Uname
Remove any initial definition of name, where name is a
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CALLS(1) CALLS(1)
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 directories 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 func-
tions.
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