basic,shared: mark eligible functions with _pure_/_const_

Following the recent witch hunt done to static inline functions
I figure we should at least give the compiler some more hint
on optimizations.

src/shared/exit-status.h

@@ -103,8 +103,8 @@ typedef enum ExitClean {
         EXIT_CLEAN_COMMAND,
 } ExitClean;
 
-bool is_clean_exit(int code, int status, ExitClean clean, const ExitStatusSet *success_status);
+bool is_clean_exit(int code, int status, ExitClean clean, const ExitStatusSet *success_status) _pure_;
 
 void exit_status_set_free(ExitStatusSet *x);
-bool exit_status_set_is_empty(const ExitStatusSet *x);
-bool exit_status_set_test(const ExitStatusSet *x, int code, int status);
+bool exit_status_set_is_empty(const ExitStatusSet *x) _pure_;
+bool exit_status_set_test(const ExitStatusSet *x, int code, int status) _pure_;

src/shared/gpt.h

@@ -29,19 +29,19 @@ typedef enum PartitionDesignator {
         _PARTITION_DESIGNATOR_INVALID = -EINVAL,
 } PartitionDesignator;
 
-bool partition_designator_is_versioned(PartitionDesignator d);
+bool partition_designator_is_versioned(PartitionDesignator d) _const_;
 
-PartitionDesignator partition_verity_of(PartitionDesignator p);
-PartitionDesignator partition_verity_sig_of(PartitionDesignator p);
-PartitionDesignator partition_verity_to_data(PartitionDesignator d);
-PartitionDesignator partition_verity_sig_to_data(PartitionDesignator d);
+PartitionDesignator partition_verity_of(PartitionDesignator p) _const_;
+PartitionDesignator partition_verity_sig_of(PartitionDesignator p) _const_;
+PartitionDesignator partition_verity_to_data(PartitionDesignator d) _const_;
+PartitionDesignator partition_verity_sig_to_data(PartitionDesignator d) _const_;
 
 const char* partition_designator_to_string(PartitionDesignator d) _const_;
 PartitionDesignator partition_designator_from_string(const char *name) _pure_;
 
 const char* partition_mountpoint_to_string(PartitionDesignator d) _const_;
 
-const char* gpt_partition_type_uuid_to_string(sd_id128_t id);
+const char* gpt_partition_type_uuid_to_string(sd_id128_t id) _const_;
 const char* gpt_partition_type_uuid_to_string_harder(
                 sd_id128_t id,
                 char buffer[static SD_ID128_UUID_STRING_MAX]);
@@ -49,7 +49,7 @@ const char* gpt_partition_type_uuid_to_string_harder(
 #define GPT_PARTITION_TYPE_UUID_TO_STRING_HARDER(id) \
         gpt_partition_type_uuid_to_string_harder((id), (char[SD_ID128_UUID_STRING_MAX]) {})
 
-Architecture gpt_partition_type_uuid_to_arch(sd_id128_t id);
+Architecture gpt_partition_type_uuid_to_arch(sd_id128_t id) _const_;
 
 typedef struct GptPartitionType {
         sd_id128_t uuid;
@@ -65,14 +65,14 @@ int gpt_partition_label_valid(const char *s);
 GptPartitionType gpt_partition_type_from_uuid(sd_id128_t id);
 int gpt_partition_type_from_string(const char *s, GptPartitionType *ret);
 
-GptPartitionType gpt_partition_type_override_architecture(GptPartitionType type, Architecture arch);
+GptPartitionType gpt_partition_type_override_architecture(GptPartitionType type, Architecture arch) _const_;
 
 const char* gpt_partition_type_mountpoint_nulstr(GptPartitionType type);
 
-bool gpt_partition_type_knows_read_only(GptPartitionType type);
-bool gpt_partition_type_knows_growfs(GptPartitionType type);
-bool gpt_partition_type_knows_no_auto(GptPartitionType type);
-bool gpt_partition_type_has_filesystem(GptPartitionType type);
+bool gpt_partition_type_knows_read_only(GptPartitionType type) _const_;
+bool gpt_partition_type_knows_growfs(GptPartitionType type) _const_;
+bool gpt_partition_type_knows_no_auto(GptPartitionType type) _const_;
+bool gpt_partition_type_has_filesystem(GptPartitionType type) _const_;
 
 typedef struct {
         uint8_t partition_type_guid[16];
@@ -100,4 +100,4 @@ typedef struct {
         le32_t partition_entry_array_crc32;
 } _packed_ GptHeader;
 
-bool gpt_header_has_signature(const GptHeader *p);
+bool gpt_header_has_signature(const GptHeader *p) _pure_;

src/shared/group-record.h

@@ -52,5 +52,5 @@ UserDisposition group_record_disposition(GroupRecord *h);
 
 bool group_record_matches_group_name(const GroupRecord *g, const char *groupname);
 
-bool group_record_is_root(const GroupRecord *g);
-bool group_record_is_nobody(const GroupRecord *g);
+bool group_record_is_root(const GroupRecord *g) _pure_;
+bool group_record_is_nobody(const GroupRecord *g) _pure_;

src/shared/main-func.h

@@ -19,14 +19,14 @@ void main_finalize(int r, int exit_status);
                 return result_to_return_value(r);                       \
         }
 
-int exit_failure_if_negative(int result);
+int exit_failure_if_negative(int result) _const_;
 
 /* Negative return values from impl are mapped to EXIT_FAILURE, and
  * everything else means success! */
 #define DEFINE_MAIN_FUNCTION(impl)                                      \
         _DEFINE_MAIN_FUNCTION(,impl(argc, argv), exit_failure_if_negative, exit_failure_if_negative)
 
-int exit_failure_if_nonzero(int result);
+int exit_failure_if_nonzero(int result) _const_;
 
 /* Zero is mapped to EXIT_SUCCESS, negative values are mapped to EXIT_FAILURE,
  * and positive values are propagated.

src/shared/mount-setup.h

@@ -3,8 +3,8 @@
 
 #include "forward.h"
 
-bool mount_point_is_api(const char *path);
-bool mount_point_ignore(const char *path);
+bool mount_point_is_api(const char *path) _pure_;
+bool mount_point_ignore(const char *path) _pure_;
 
 int mount_setup_early(void);
 int mount_setup(bool loaded_policy, bool leave_propagation);

src/shared/nsflags.h

@@ -22,4 +22,4 @@
 
 int namespace_flags_from_string(const char *name, unsigned long *ret);
 int namespace_flags_to_string(unsigned long flags, char **ret);
-const char* namespace_single_flag_to_string(unsigned long flag);
+const char* namespace_single_flag_to_string(unsigned long flag) _const_;