| Message ID | CAAkRFZLuXyevU9xUmq1AFKEq+JjTH-G=Oe0pWWY=MkkxMR5jHA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 07/18/14 22:41, Xinliang David Li wrote: > Hi, the following patch implements a new dumper interface to allow > dumping of profile data for all instrumented shared libraries. > > For good reasons, existing libgcov implements the dumping on a > per-shared library basis (i.e., gcov_exit is hidden, gcov_list is file > static). This allows each shared library's profile data to be dumped > independently with separate summary data. The downside is that there > is no interface that can be invoked to dump profile data for all > shared modules. This seems like useful functionality, but I don't think this is the right way to do this. You're duplicating the gcov info object chain. Why can't you expose gcov_list from gcov-driver.c (possibly with a different name, of course? nathan
The gcov_info chain is not duplicated -- there is already one chain (linking only modules of the library) per shared library in current implementation. My change does not affect underlying behavior at all -- it merely introduces a new interface to access private dumper methods associated with shared libs. David On Sun, Jul 20, 2014 at 12:42 PM, Nathan Sidwell <nathan@acm.org> wrote: > On 07/18/14 22:41, Xinliang David Li wrote: >> >> Hi, the following patch implements a new dumper interface to allow >> dumping of profile data for all instrumented shared libraries. >> >> For good reasons, existing libgcov implements the dumping on a >> per-shared library basis (i.e., gcov_exit is hidden, gcov_list is file >> static). This allows each shared library's profile data to be dumped >> independently with separate summary data. The downside is that there >> is no interface that can be invoked to dump profile data for all >> shared modules. > > > This seems like useful functionality, but I don't think this is the right > way to do this. You're duplicating the gcov info object chain. Why can't > you expose gcov_list from gcov-driver.c (possibly with a different name, of > course? > > nathan
On 07/20/14 21:38, Xinliang David Li wrote: > The gcov_info chain is not duplicated -- there is already one chain > (linking only modules of the library) per shared library in current > implementation. My change does not affect underlying behavior at all > -- it merely introduces a new interface to access private dumper > methods associated with shared libs. ah, got it. thanks for clarifying. Can't help thinking gcov_init should be doing this, and wondering about dlload/dlclose. Let me think nathan
Index: libgcc/ChangeLog =================================================================== --- libgcc/ChangeLog (revision 212682) +++ libgcc/ChangeLog (working copy) @@ -1,3 +1,9 @@ +2014-07-18 Xinliang David Li <davidxl@google.com> + + * libgcov-driver.c: Force __gcov_dump to be exported + * libgcov-interface.c (register_dumper): New function. + (__gcov_dump_all): Ditto. + 2014-07-14 Richard Biener <rguenther@suse.de> * libgcov.h (struct gcov_fn_info): Make ctrs size 1. Index: libgcc/libgcov-driver.c =================================================================== --- libgcc/libgcov-driver.c (revision 212682) +++ libgcc/libgcov-driver.c (working copy) @@ -55,6 +55,13 @@ extern void set_gcov_dump_complete (void extern void reset_gcov_dump_complete (void) ATTRIBUTE_HIDDEN; extern int get_gcov_dump_complete (void) ATTRIBUTE_HIDDEN; extern void set_gcov_list (struct gcov_info *) ATTRIBUTE_HIDDEN; + +#ifndef IN_GCOV_TOOL + +/* Creates strong reference to force _gcov_dump.o to be linked + in shared library for exported interfaces. */ +void (*__gcov_dummy_ref)(void) = &__gcov_dump; +#endif struct gcov_fn_buffer { Index: libgcc/libgcov-interface.c =================================================================== --- libgcc/libgcov-interface.c (revision 212682) +++ libgcc/libgcov-interface.c (working copy) @@ -115,6 +115,43 @@ __gcov_dump (void) set_gcov_dump_complete (); } +typedef void (*gcov_dumper_type) (void); +struct dumper_entry +{ + gcov_dumper_type dumper; + struct dumper_entry *next_dumper; +}; + +static struct dumper_entry this_dumper = {&__gcov_dump, 0}; + +/* global dumper list with default visibilty. */ +struct dumper_entry *__gcov_dumper_list; + + +__attribute__((constructor)) +static void +register_dumper (void) +{ + this_dumper.next_dumper = __gcov_dumper_list; + __gcov_dumper_list = &this_dumper; +} + +/* Public interface to dump profile data for all shared libraries + via registered dumpers from the libraries. This interface + has default visibility (unlike gcov_dump which has hidden + visbility. */ + +void +__gcov_dump_all (void) +{ + struct dumper_entry *dumper = __gcov_dumper_list; + while (dumper) + { + dumper->dumper (); + dumper = dumper->next_dumper; + } +} + #endif /* L_gcov_dump */ Index: libgcc/libgcov.h =================================================================== --- libgcc/libgcov.h (revision 212682) +++ libgcc/libgcov.h (working copy) @@ -218,8 +218,14 @@ extern void __gcov_flush (void) ATTRIBUT /* Function to reset all counters to 0. */ extern void __gcov_reset (void); -/* Function to enable early write of profile information so far. */ -extern void __gcov_dump (void); +/* Function to enable early write of profile information so far. + __GCOV_DUMP is also used by __GCOV_DUMP_ALL. The latter + depends on __GCOV_DUMP to have hidden or protected visibility + so that each library has its own copy of the registered dumper. */ +extern void __gcov_dump (void) ATTRIBUTE_HIDDEN; + +/* Call __gcov_dump registered from each shared library. */ +void __gcov_dump_all (void); /* The merge function that just sums the counters. */ extern void __gcov_merge_add (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;