coverage.c File Reference

#include "gt-coverage.h"

Include dependency graph for coverage.c:

Data Structures
struct	coverage_data
struct	counts_entry

Typedefs
typedef struct counts_entry	counts_entry_t

Functions
static void	read_counts_file (void)
static tree	build_var (tree, tree, int)
static void	build_fn_info_type (tree, unsigned, tree)
static void	build_info_type (tree, tree)
static tree	build_fn_info (const struct coverage_data *, tree, tree)
static tree	build_info (tree, tree)
static bool	coverage_obj_init (void)
static vec< constructor_elt, va_gc > *	coverage_obj_fn (vec< constructor_elt, va_gc > *, tree, struct coverage_data const *)
static void	coverage_obj_finish (vec< constructor_elt, va_gc > *)
tree	get_gcov_type ()
static tree	get_gcov_unsigned_t ()
gcov_type *	get_coverage_counts (unsigned counter, unsigned expected, unsigned cfg_checksum, unsigned lineno_checksum, const struct gcov_ctr_summary **summary)
int	coverage_counter_alloc ()
tree	tree_coverage_counter_ref ()
tree	tree_coverage_counter_addr ()
static unsigned	coverage_checksum_string ()
unsigned	coverage_compute_lineno_checksum ()
unsigned	coverage_compute_profile_id ()
unsigned	coverage_compute_cfg_checksum ()
int	coverage_begin_function ()
void	coverage_end_function ()
static tree	build_var ()
static void	build_fn_info_type ()
static tree	build_fn_info ()
static void	build_info_type ()
static tree	build_info ()
static void	build_init_ctor ()
static void	coverage_obj_finish ()
void	coverage_init ()
void	coverage_finish ()

Variables
static struct coverage_data *	functions_head = 0
static struct coverage_data **	functions_tail = &functions_head
static unsigned	no_coverage = 0
static unsigned	prg_ctr_mask
static unsigned	fn_ctr_mask
static tree	fn_v_ctrs [GCOV_COUNTERS]
static unsigned	fn_n_ctrs [GCOV_COUNTERS]
static unsigned	fn_b_ctrs [GCOV_COUNTERS]
static tree	gcov_info_var
static tree	gcov_fn_info_type
static tree	gcov_fn_info_ptr_type
static char *	bbg_file_name
static unsigned	bbg_file_stamp
static char *	da_file_name
static const char *const	ctr_merge_functions [GCOV_COUNTERS] = GCOV_MERGE_FUNCTIONS
static const char *const	ctr_names [GCOV_COUNTERS] = GCOV_COUNTER_NAMES
static hash_table< counts_entry >	counts_hash

---

Typedef Documentation

typedef struct counts_entry counts_entry_t

   Counts information for a function.  

---

Function Documentation

static tree build_fn_info ( const struct coverage_data *  , tree  , tree    )

static

static tree build_fn_info ( )

static

   Returns a CONSTRUCTOR for a gcov_fn_info.  DATA is
   the coverage data for the function and TYPE is the gcov_fn_info
   RECORD_TYPE.  KEY is the object file key.  

     key 

     ident 

     lineno_checksum 

     cfg_checksum 

     counters 

static void build_fn_info_type ( tree  , unsigned  , tree    )

static

static void build_fn_info_type ( )

static

   Creates the gcov_fn_info RECORD_TYPE.  

     ctr_info::num 

     ctr_info::values 

     key 

     ident 

     lineno_checksum 

     cfg checksum 

     counters 

static tree build_info ( tree  , tree    )

static

Referenced by coverage_obj_init().

static tree build_info ( )

static

   Returns a CONSTRUCTOR for the gcov_info object.  INFO_TYPE is the
   gcov_info structure type, FN_ARY is the array of pointers to
   function info objects.  

     Version ident 

     next -- NULL 

     stamp 

     Filename 

     merge fn array -- NULL slots indicate unmeasured counters 

             Initialize assembler name so we can stream out. 

     n_functions 

     functions 

static void build_info_type ( tree  , tree    )

static

static void build_info_type ( )

static

   Create gcov_info struct.  TYPE is the incomplete RECORD_TYPE to be
   completed, and FN_INFO_PTR_TYPE is a pointer to the function info type.  

     Version ident 

     next pointer 

     stamp 

     Filename 

     merge fn array 

     n_functions 

     function_info pointer pointer 

static void build_init_ctor ( )

static

   Generate the constructor function to call __gcov_init.  

     Build a decl for __gcov_init.  

     Generate a call to __gcov_init(&gcov_info).  

     Generate a constructor to run it.  

static tree build_var ( tree  , tree  , int    )

static

static tree build_var ( )

static

   Build a coverage variable of TYPE for function FN_DECL.  If COUNTER
   >= 0 it is a counter array, otherwise it is the function structure.  

int coverage_begin_function

(

)

   Begin output to the notes file for the current function.
   Writes the function header. Returns nonzero if data should be output.  

     We don't need to output .gcno file unless we're under -ftest-coverage
     (e.g. -fprofile-arcs/generate/use don't need .gcno to work). 

     Announce function 

References bbg_file_name, and warning().

static unsigned coverage_checksum_string ( )

static

   Generate a checksum for a string.  CHKSUM is the current
   checksum.  

     Look for everything that looks if it were produced by
     get_file_function_name and zero out the second part
     that may result from flag_random_seed.  This is not critical
     as the checksums are used only for sanity checking.  

         C++ namespaces do have scheme:
         _GLOBAL__N_<filename>_<wrongmagicnumber>_<magicnumber>functionname
       since filename might contain extra underscores there seems
       to be no better chance then walk all possible offsets looking
       for magicnumber.  

unsigned coverage_compute_cfg_checksum

(

void

)

   Compute cfg checksum for the current function.
   The checksum is calculated carefully so that
   source code changes that doesn't affect the control flow graph
   won't change the checksum.
   This is to make the profile data useable across source code change.
   The downside of this is that the compiler may use potentially
   wrong profile data - that the source code change has non-trivial impact
   on the validity of profile data (e.g. the reversed condition)
   but the compiler won't detect the change and use the wrong profile data.  

unsigned coverage_compute_lineno_checksum

(

void

)

   Compute checksum for the current function.  We generate a CRC32.  

unsigned coverage_compute_profile_id

(

)

   Compute profile ID.  This is better to be unique in whole program.  

     Non-negative integers are hopefully small enough to fit in all targets.  

References crc32_byte(), edge_def::dest, basic_block_def::index, and basic_block_def::succs.

int coverage_counter_alloc

(

)

   Allocate NUM counters of type COUNTER. Returns nonzero if the
   allocation succeeded.  

References build_int_cst(), fn_b_ctrs, fn_n_ctrs, fn_v_ctrs, gcov_type_node, and get_gcov_type().

void coverage_end_function

(

)

   Finish coverage data for the current function. Verify no output
   error has occurred.  Save function coverage counts.  

         If the function is extern (i.e. extern inline), then we won't
         be outputting it, so don't chain it onto the function
         list.  

References build_array_type(), build_index_type(), fn_n_ctrs, get_gcov_type(), and varpool_finalize_decl().

void coverage_finish

(

void

)

   Performs file-level cleanup.  Close notes file, generate coverage
   variables and constructor.  

       Only remove the da file, if we're emitting coverage code and
       cannot uniquely stamp it.  If we can stamp it, libgcov will DTRT.  

void coverage_init

(

)

   Perform file-level initialization. Read in data file, generate name
   of notes file.  

     Since coverage_init is invoked very early, before the pass
     manager, we need to set up the dumping explicitly. This is
     similar to the handling in finish_optimization_passes.  

     Name of da file.  

     Name of bbg file.  

static void coverage_obj_finish ( vec< constructor_elt, va_gc > *  )

static

static void coverage_obj_finish ( )

static

   Finalize the coverage data.  Generates the array of pointers to
   function objects from CTOR.  Generate the gcov_info initializer.  

static vec< constructor_elt, va_gc > * coverage_obj_fn ( vec< constructor_elt, va_gc > *  ctor, tree  fn, struct coverage_data const *  data  )

static

   Generate the coverage function info for FN and DATA.  Append a
   pointer to that object to CTOR and return the appended CTOR.  

References bbg_file_name, bbg_file_stamp, error(), gcov_open(), gcov_write_unsigned(), memcpy(), and strlen().

static bool coverage_obj_init ( )

static

   Create the gcov_info types and object.  Generate the constructor
   function to call __gcov_init.  Does not generate the initializer
   for the object.  Returns TRUE if coverage data is being emitted.  

     Prune functions.  

         The function is not being emitted, remove from list.  

     Build the info and fn_info types.  These are mutually recursive.  

     Build the gcov info var, this is referred to in its own
     initializer.  

References build_array_type(), build_constructor(), build_index_type(), build_info(), build_qualified_type(), gcov_fn_info_ptr_type, gcov_info_var, get_identifier(), TYPE_QUAL_CONST, varpool_finalize_decl(), and vec_safe_length().

gcov_type* get_coverage_counts	(	unsigned	counter,
		unsigned	expected,
		unsigned	cfg_checksum,
		unsigned	lineno_checksum,
		const struct gcov_ctr_summary **	summary
	)

   Returns the counters for a particular tag.  

     No hash table, no counts.  

       The function was not emitted, or is weak and not chosen in the
       final executable.  Silently fail, because there's nothing we
       can do about it.  

tree get_gcov_type

(

void

)

   Return the type node for gcov_type.  

Referenced by coverage_counter_alloc(), coverage_end_function(), and gimple_init_edge_profiler().

static tree get_gcov_unsigned_t ( )

static

   Return the type node for gcov_unsigned_t.  

static void read_counts_file ( void  )

static

   Forward declarations.  

   Read in the counts file, if available.  

     Read the stamp, used for creating a generation count.  

References counts_hash, and error().

tree tree_coverage_counter_addr

(

)

   Generate a tree to access the address of COUNTER NO.  

     "no" here is an array index, scaled to bytes later.  

References offset.

Referenced by gimple_gen_one_value_profiler(), and gimple_gen_pow2_profiler().

tree tree_coverage_counter_ref

(

)

   Generate a tree to access COUNTER NO.  

     "no" here is an array index, scaled to bytes later.  

---

Variable Documentation

char* bbg_file_name

static

   Name of the notes (gcno) output file.  The "bbg" prefix is for
   historical reasons, when the notes file contained only the
   basic block graph notes.
   If this is NULL we're not writing to the notes file.  

Referenced by coverage_begin_function(), and coverage_obj_fn().

unsigned bbg_file_stamp

static

   File stamp for notes file.  

Referenced by coverage_obj_fn().

hash_table<counts_entry> counts_hash

static

   Hash table of count data.  

Referenced by read_counts_file().

const char* const ctr_merge_functions[GCOV_COUNTERS] = GCOV_MERGE_FUNCTIONS

static

   The names of merge functions for counters.  

const char* const ctr_names[GCOV_COUNTERS] = GCOV_COUNTER_NAMES

static

char* da_file_name

static

   Name of the count data (gcda) file.  

unsigned fn_b_ctrs[GCOV_COUNTERS]

static

Referenced by coverage_counter_alloc().

unsigned fn_ctr_mask

static

   Counter information for current function.  

unsigned fn_n_ctrs[GCOV_COUNTERS]

static

Referenced by coverage_counter_alloc(), and coverage_end_function().

tree fn_v_ctrs[GCOV_COUNTERS]

static

Referenced by coverage_counter_alloc().

struct coverage_data* functions_head = 0

static

struct coverage_data** functions_tail = &functions_head

static

tree gcov_fn_info_ptr_type

static

Referenced by coverage_obj_init().

tree gcov_fn_info_type

static

tree gcov_info_var

static

   Coverage info VAR_DECL and function info type nodes.  

Referenced by coverage_obj_init().

unsigned no_coverage = 0

static

unsigned prg_ctr_mask

static

   Cumulative counter information for whole program.