Fix very high stack usage in SSL debug code
Use a switch instead of an array. The array was very hollow for some enum
types such as mbedtls_ssl_protocol_version (which formerly used small
values, but switched to using the protocol encoding as enum values in Mbed
TLS 3.2.0). Optimizing compilers know how to compile a switch into a lookup
table when the range warrants it.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/generate_ssl_debug_helpers.py b/scripts/generate_ssl_debug_helpers.py
index 3127afc..0af7b8f 100755
--- a/scripts/generate_ssl_debug_helpers.py
+++ b/scripts/generate_ssl_debug_helpers.py
@@ -209,24 +209,18 @@
continue
member = field.strip().split()[0]
translation_table.append(
- '{space}[{member}] = "{member}",'.format(member=member,
- space=' '*8)
+ '{space}case {member}:\n{space} return "{member};";'
+ .format(member=member, space=' '*8)
)
body = textwrap.dedent('''\
const char *{name}_str( {prototype} in )
{{
- const char * in_to_str[]=
- {{
+ switch (in) {{
{translation_table}
- }};
-
- if( in > ( sizeof( in_to_str )/sizeof( in_to_str[0]) - 1 ) ||
- in_to_str[ in ] == NULL )
- {{
- return "UNKNOWN_VALUE";
+ default:
+ return "UNKNOWN_VALUE";
}}
- return in_to_str[ in ];
}}
''')
body = body.format(translation_table='\n'.join(translation_table),