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 current configuration at 11# include/mbedtls/config.h. The idea is that the config.h contains ALL the 12# compile time configurations available in Mbed TLS (commented or uncommented). 13# This script extracts the configuration macros from the config.h and this 14# information is used to automatically generate the body of the query_config() 15# function by using the template in scripts/data_files/query_config.fmt. 16# 17# Usage: ./scripts/generate_query_config.pl without arguments 18# 19# Copyright The Mbed TLS Contributors 20# SPDX-License-Identifier: Apache-2.0 21# 22# Licensed under the Apache License, Version 2.0 (the "License"); you may 23# not use this file except in compliance with the License. 24# You may obtain a copy of the License at 25# 26# http://www.apache.org/licenses/LICENSE-2.0 27# 28# Unless required by applicable law or agreed to in writing, software 29# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 30# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 31# See the License for the specific language governing permissions and 32# limitations under the License. 33 34use strict; 35 36my $config_file = "./include/mbedtls/config.h"; 37 38my $query_config_format_file = "./scripts/data_files/query_config.fmt"; 39my $query_config_file = "./programs/test/query_config.c"; 40 41# Excluded macros from the generated query_config.c. For example, macros that 42# have commas or function-like macros cannot be transformed into strings easily 43# using the preprocessor, so they should be excluded or the preprocessor will 44# throw errors. 45my @excluded = qw( 46MBEDTLS_SSL_CIPHERSUITES 47MBEDTLS_PARAM_FAILED 48); 49my $excluded_re = join '|', @excluded; 50 51open(CONFIG_FILE, "$config_file") or die "Opening config file '$config_file': $!"; 52 53# This variable will contain the string to replace in the CHECK_CONFIG of the 54# format file 55my $config_check = ""; 56 57while (my $line = <CONFIG_FILE>) { 58 if ($line =~ /^(\/\/)?\s*#\s*define\s+(MBEDTLS_\w+).*/) { 59 my $name = $2; 60 61 # Skip over the macro that prevents multiple inclusion 62 next if "MBEDTLS_CONFIG_H" eq $name; 63 64 # Skip over the macro if it is in the ecluded list 65 next if $name =~ /$excluded_re/; 66 67 $config_check .= "#if defined($name)\n"; 68 $config_check .= " if( strcmp( \"$name\", config ) == 0 )\n"; 69 $config_check .= " {\n"; 70 $config_check .= " MACRO_EXPANSION_TO_STR( $name );\n"; 71 $config_check .= " return( 0 );\n"; 72 $config_check .= " }\n"; 73 $config_check .= "#endif /* $name */\n"; 74 $config_check .= "\n"; 75 } 76} 77 78# Read the full format file into a string 79local $/; 80open(FORMAT_FILE, "$query_config_format_file") or die "Opening query config format file '$query_config_format_file': $!"; 81my $query_config_format = <FORMAT_FILE>; 82close(FORMAT_FILE); 83 84# Replace the body of the query_config() function with the code we just wrote 85$query_config_format =~ s/CHECK_CONFIG/$config_check/g; 86 87# Rewrite the query_config.c file 88open(QUERY_CONFIG_FILE, ">$query_config_file") or die "Opening destination file '$query_config_file': $!"; 89print QUERY_CONFIG_FILE $query_config_format; 90close(QUERY_CONFIG_FILE); 91