1#! /usr/bin/env perl
2
3# Generate query_config.c
4#
5# The file query_config.c contains a C function that can be used to check if
6# a configuration macro is defined and to retrieve its expansion in string
7# form (if any). This facilitates querying the compile time configuration of
8# the library, for example, for testing.
9#
10# The query_config.c is generated from the default configuration files
11# include/mbedtls/mbedtls_config.h and include/psa/crypto_config.h.
12# The idea is that mbedtls_config.h and crypto_config.h contain ALL the
13# compile time configurations available in Mbed TLS (commented or uncommented).
14# This script extracts the configuration macros from the two files and this
15# information is used to automatically generate the body of the query_config()
16# function by using the template in scripts/data_files/query_config.fmt.
17#
18# Usage: scripts/generate_query_config.pl without arguments, or
19# generate_query_config.pl mbedtls_config_file psa_crypto_config_file template_file output_file
20#
21# Copyright The Mbed TLS Contributors
22# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
23
24use strict;
25
26my ($mbedtls_config_file, $psa_crypto_config_file, $query_config_format_file, $query_config_file);
27
28my $default_mbedtls_config_file = "./include/mbedtls/mbedtls_config.h";
29my $default_psa_crypto_config_file = "./tf-psa-crypto/include/psa/crypto_config.h";
30my $default_query_config_format_file = "./scripts/data_files/query_config.fmt";
31my $default_query_config_file = "./programs/test/query_config.c";
32
33if( @ARGV ) {
34    die "Invalid number of arguments - usage: $0 [MBED_TLS_CONFIG_FILE PSA_CRYPTO_CONFIG_FILE TEMPLATE_FILE OUTPUT_FILE]" if scalar @ARGV != 4;
35    ($mbedtls_config_file, $psa_crypto_config_file, $query_config_format_file, $query_config_file) = @ARGV;
36
37    -f $mbedtls_config_file or die "No such file: $mbedtls_config_file";
38    -f $psa_crypto_config_file or die "No such file: $psa_crypto_config_file";
39    -f $query_config_format_file or die "No such file: $query_config_format_file";
40} else {
41    $mbedtls_config_file = $default_mbedtls_config_file;
42    $psa_crypto_config_file = $default_psa_crypto_config_file;
43    $query_config_format_file = $default_query_config_format_file;
44    $query_config_file = $default_query_config_file;
45
46    unless(-f $mbedtls_config_file && -f $query_config_format_file  && -f $psa_crypto_config_file) {
47        chdir '..' or die;
48        -f $mbedtls_config_file && -f $query_config_format_file && -f $psa_crypto_config_file
49          or die "No arguments supplied, must be run from project root or a first-level subdirectory\n";
50    }
51}
52-f 'include/mbedtls/build_info.h'
53  or die "$0: must be run from project root, or from a first-level subdirectory with no arguments\n";
54
55# Excluded macros from the generated query_config.c. For example, macros that
56# have commas or function-like macros cannot be transformed into strings easily
57# using the preprocessor, so they should be excluded or the preprocessor will
58# throw errors.
59my @excluded = qw(
60MBEDTLS_SSL_CIPHERSUITES
61);
62my $excluded_re = join '|', @excluded;
63
64# This variable will contain the string to replace in the CHECK_CONFIG of the
65# format file
66my $config_check = "";
67my $list_config = "";
68
69for my $config_file ($mbedtls_config_file, $psa_crypto_config_file) {
70
71    next unless defined($config_file);  # we might not have been given a PSA crypto config file
72
73    open(CONFIG_FILE, "<", $config_file) or die "Opening config file '$config_file': $!";
74
75    while (my $line = <CONFIG_FILE>) {
76        if ($line =~ /^(\/\/)?\s*#\s*define\s+(MBEDTLS_\w+|PSA_WANT_\w+).*/) {
77            my $name = $2;
78
79            # Skip over the macro if it is in the excluded list
80            next if $name =~ /$excluded_re/;
81
82            $config_check .= <<EOT;
83#if defined($name)
84    if( strcmp( "$name", config ) == 0 )
85    {
86        MACRO_EXPANSION_TO_STR( $name );
87        return( 0 );
88    }
89#endif /* $name */
90
91EOT
92
93            $list_config .= <<EOT;
94#if defined($name)
95    OUTPUT_MACRO_NAME_VALUE($name);
96#endif /* $name */
97
98EOT
99        }
100    }
101
102    close(CONFIG_FILE);
103}
104
105# We need to include all the headers with public APIs in case they
106# define a macro to its default value when that configuration is not
107# set in a header included by build_info.h (crypto_config.h,
108# mbedtls_config.h, *adjust*.h). Some module-specific macros are set
109# in that module's header. For simplicity, include all headers, with
110# some ad hoc knowledge of headers that are included by other headers
111# and should not be included directly. We don't include internal headers
112# because those should not define configurable macros.
113my @header_files = ();
114my @header_roots = qw(
115                         include
116                         tf-psa-crypto/include
117                         tf-psa-crypto/drivers/builtin/include
118                    );
119for my $root (@header_roots) {
120    my @paths = glob "$root/*/*.h $root/*/*/*.h";
121    map {s!^\Q$root/!!} @paths;
122    # Exclude some headers that are included by build_info.h and cannot
123    # be included directly.
124    push @header_files, grep {!m[
125            ^psa/crypto_(platform|struct)\.h$ | # have alt versions, included by psa/crypto.h anyway
126            ^mbedtls/platform_time\.h$ | # errors without time.h
127            _config\.h |
128            [/_]adjust[/_]
129        ]x} @paths;
130}
131my $include_headers = join('', map {"#include <$_>\n"} @header_files);
132
133# Read the full format file into a string
134local $/;
135open(FORMAT_FILE, "<", $query_config_format_file) or die "Opening query config format file '$query_config_format_file': $!";
136my $query_config_format = <FORMAT_FILE>;
137close(FORMAT_FILE);
138
139# Replace the body of the query_config() function with the code we just wrote
140$query_config_format =~ s/INCLUDE_HEADERS/$include_headers/g;
141$query_config_format =~ s/CHECK_CONFIG/$config_check/g;
142$query_config_format =~ s/LIST_CONFIG/$list_config/g;
143
144# Rewrite the query_config.c file
145open(QUERY_CONFIG_FILE, ">", $query_config_file) or die "Opening destination file '$query_config_file': $!";
146print QUERY_CONFIG_FILE $query_config_format;
147close(QUERY_CONFIG_FILE);
148