1 files changed, 75 insertions, 0 deletions
diff --git a/scripts/generate_query_config.pl b/scripts/generate_query_config.pl
new file mode 100755
index 00000000..f15e03a3
--- /dev/null
+++ b/scripts/generate_query_config.pl
@@ -0,0 +1,75 @@
+#! /usr/bin/env perl
+
+# Generate query_config.c
+#
+# The file query_config.c contains a C function that can be used to check if
+# a configuration macro is defined and to retrieve its expansion in string
+# form (if any). This facilitates querying the compile time configuration of
+# the library, for example, for testing.
+#
+# The query_config.c is generated from the current configuration at
+# include/mbedtls/config.h. The idea is that the config.h contains ALL the
+# compile time configurations available in Mbed TLS (commented or uncommented).
+# This script extracts the configuration macros from the config.h and this
+# information is used to automatically generate the body of the query_config()
+# function by using the template in scripts/data_files/query_config.fmt.
+#
+# Usage: ./scripts/generate_query_config.pl without arguments
+
+use strict;
+
+my $config_file = "./include/mbedtls/config.h";
+
+my $query_config_format_file = "./scripts/data_files/query_config.fmt";
+my $query_config_file = "./programs/ssl/query_config.c";
+
+# Excluded macros from the generated query_config.c. For example, macros that
+# have commas or function-like macros cannot be transformed into strings easily
+# using the preprocessor, so they should be excluded or the preprocessor will
+# throw errors.
+my @excluded = qw(
+MBEDTLS_SSL_CIPHERSUITES
+MBEDTLS_PARAM_FAILED
+);
+my $excluded_re = join '|', @excluded;
+
+open(CONFIG_FILE, "$config_file") or die "Opening config file '$config_file': $!";
+
+# This variable will contain the string to replace in the CHECK_CONFIG of the
+# format file
+my $config_check = "";
+
+while (my $line = <CONFIG_FILE>) {
+    if ($line =~ /^(\/\/)?\s*#\s*define\s+(MBEDTLS_\w+).*/) {
+        my $name = $2;
+
+        # Skip over the macro that prevents multiple inclusion
+        next if "MBEDTLS_CONFIG_H" eq $name;
+
+        # Skip over the macro if it is in the ecluded list
+        next if $name =~ /$excluded_re/;
+
+        $config_check .= "#if defined($name)\n";
+        $config_check .= "    if( strcmp( \"$name\", config ) == 0 )\n";
+        $config_check .= "    {\n";
+        $config_check .= "        MACRO_EXPANSION_TO_STR( $name );\n";
+        $config_check .= "        return( 0 );\n";
+        $config_check .= "    }\n";
+        $config_check .= "#endif /* $name */\n";
+        $config_check .= "\n";
+    }
+}
+
+# Read the full format file into a string
+local $/;
+open(FORMAT_FILE, "$query_config_format_file") or die "Opening query config format file '$query_config_format_file': $!";
+my $query_config_format = <FORMAT_FILE>;
+close(FORMAT_FILE);
+
+# Replace the body of the query_config() function with the code we just wrote
+$query_config_format =~ s/CHECK_CONFIG/$config_check/g;
+
+# Rewrite the query_config.c file
+open(QUERY_CONFIG_FILE, ">$query_config_file") or die "Opening destination file '$query_config_file': $!";
+print QUERY_CONFIG_FILE $query_config_format;
+close(QUERY_CONFIG_FILE);