The policy parser does not set errno, so the libqpol code assumes the
errors from parser code are always invalid syntax, rather than something
else like out of memory. This may not always be the case, but any other
kind of error is unlikely (and likely catastrophic)
libqpol' hashtable iterator uses non-const data, so
ebitmap_state_get_cur_polcap needs to return a "void *" out of a "const
char *".
This fixes the following gcc warning:
libqpol/iterator.c: In function 'ebitmap_state_get_cur_polcap':
libqpol/iterator.c:653:2: warning: return discards 'const' qualifier
from pointer target type
return sepol_polcap_getname(es->cur);
^
This also adds a warning from "gcc -Wcast-qual" but compiling with this
switch leads to way more warnings.
Literal strings are located in read-only memory and should be "const
char*". "gcc -Wwrite-strings" warns when using non-const literal
strings with messages like:
libqpol/policy_parse.y: In function 'yyparse':
libqpol/policy_parse.y:381:21: warning: passing argument 1 of
'insert_id' discards 'const' qualifier from pointer target type
{ if (insert_id("T",0)) return -1; }
^
Fix these warnings by using "const char*" instead of "char*" for some
function parameters.
This makes gcc report other warnings about hashtab_search (from
libsepol). This function incorrectly defines its second parameter as
"char *const key" instead of "const char* key" (this fact is hidden
behind hashtab_key_t typedef).
"gcc -Wwrite-strings" reported warnings when using hashtab_search (from
libsepol) with string literals as its second parameter is a non-constant
string.
Indeed /usr/include/sepol/policydb/hashtab.h contains:
typedef char *hashtab_key_t;
/* ... */
extern hashtab_datum_t hashtab_search(hashtab_t h, const hashtab_key_t k);
This means the second parameter is "char *const k", not "const char *k".
As a consequence:
* Casting to "const hashtab_key_t" leads to misunderstanding the code.
* "const char*" variables need to be explicitly casted to "char*" or
"hashtab_key_t" before calling hashtab_search.
* When using "gcc -Wwrite-strings", literal strings need to be casted to
"char*" or "hashtab_key_t" before calling hashtab_search.
* "gcc -Wcast-qual" reports an awful amount of warnings due to
const-to-nonconst pointer casts.
Add missing casts to hashtab_key_t to help finding real bugs in
setools/libqpol with gcc flags.
This fixes gcc warnings like:
libqpol/avrule_query.c: In function 'qpol_avrule_get_perm_iter':
libqpol/avrule_query.c:159:14: warning: variable 'db' set but not used
[-Wunused-but-set-variable]
policydb_t *db = NULL;
^
"python setup.py build" compiles libqpol with -DNDEBUG, which disables
the effect of assert(0). abort() is not affected by NDEBUG, so use it
instead.
This fixes gcc warnings like this:
libqpol/module_compiler.c: In function 'declare_role':
libqpol/module_compiler.c:314:1: warning: control reaches end of
non-void function [-Wreturn-type]
gcc reported:
libqpol/constraint_query.c: In function 'qpol_constraint_expr_node_get_names_iter':
libqpol/constraint_query.c:783:45: error: pointer targets in passing
argument 2 of 'qpol_policy_get_policy_version' differ in signedness
[-Werror=pointer-sign]
if (qpol_policy_get_policy_version(policy, &policy_version))
^
In file included from libqpol/constraint_query.c:29:0:
libqpol/include/qpol/policy.h:250:13: note: expected 'unsigned int
*' but argument is of type 'int *'
extern int qpol_policy_get_policy_version(const qpol_policy_t * policy, unsigned int *version);
^
Python builds C extensions with -Wstrict-prototypes. This triggers
warnings when defining functions wirth () for "any number of
parameters".
Remove these warnings by always specifying parameters.
The declaration of fstat was missing. "gcc -Wall" reported:
libqpol/policy.c: In function 'qpol_policy_open_from_file_opt':
libqpol/policy.c:1060:3: warning: implicit declaration of function
'fstat' [-Wimplicit-function-declaration]
if (fstat(fd, &sb) < 0) {
^
gcc reported the following warnings:
libqpol/policy_extend.c: In function 'qpol_avrule_get_syn_avrule_iter':
libqpol/policy_extend.c:1219:3: warning: format '%S' expects
argument of type 'wchar_t *', but argument 4 has type 'char *'
[-Wformat=]
ERR(policy, "%S", strerror(error));
^
libqpol/policy_extend.c: In function 'qpol_terule_get_syn_terule_iter':
libqpol/policy_extend.c:1320:3: warning: format '%S' expects
argument of type 'wchar_t *', but argument 4 has type 'char *'
[-Wformat=]
ERR(policy, "%S", strerror(error));
^
"gcc -Wformat" needs printing functions to be marked with a format
attribute to be able to work. Add this attribute to some functions in
libqpol, found with "gcc -Werror=missing-format-attribute"
gcc documentation about format attribute:
https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
* Add printf format specifier for yyerror2 to be able to use
"gcc -Wformat-security"
* Constify message string to avoid gcc warnings about casting string
literals to non-const char*.
