Hello. There are multiple PRs (mentioned in ChangeLog) which suffer from missing capability of gcov to save counters for functions with constructor/destructor attributes. I done that by simply replacing atexit handler (gcov_exit) with a new static destructor (__gcov_exit), which has priority 99 (I did the same for __gcov_init). However, I'm not sure whether it's possible that a ctor defined in a source file can be potentially executed before __gcov_init (w/ the default priority)?
Patch survives: make check -k -j10 RUNTESTFLAGS="gcov.exp" make check -k -j10 RUNTESTFLAGS="tree-prof.exp" I've just also verified that a DSO gcov dump works as before. I'm attaching a test-case which tests both static ctors/dtors, as well as C++ ctors/dtors. Thoughts? Martin
>From 0e7f660b77628533679e6302a3f4b444166fc365 Mon Sep 17 00:00:00 2001 From: marxin <mli...@suse.cz> Date: Wed, 10 Aug 2016 12:18:45 +0200 Subject: [PATCH] gcov: dump in a static dtor instead of in an atexit handler gcc/testsuite/ChangeLog: 2016-08-10 Martin Liska <mli...@suse.cz> PR gcov-profile/7970 PR gcov-profile/16855 PR gcov-profile/44779 * g++.dg/gcov/pr16855.C: New test. gcc/ChangeLog: 2016-08-10 Martin Liska <mli...@suse.cz> PR gcov-profile/7970 PR gcov-profile/16855 PR gcov-profile/44779 * coverage.c (build_gcov_exit_decl): New function. (coverage_obj_init): Call the function and generate __gcov_exit destructor. libgcc/ChangeLog: 2016-08-10 Martin Liska <mli...@suse.cz> PR gcov-profile/7970 PR gcov-profile/16855 PR gcov-profile/44779 * libgcov-driver.c (__gcov_init): Do not register a atexit handler. (__gcov_exit): Rename from gcov_exit. * libgcov.h (__gcov_exit): Declare. --- gcc/coverage.c | 27 +++++++++++++++++++++++++-- gcc/testsuite/g++.dg/gcov/pr16855.C | 37 +++++++++++++++++++++++++++++++++++++ libgcc/libgcov-driver.c | 5 ++--- libgcc/libgcov.h | 3 +++ 4 files changed, 67 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/g++.dg/gcov/pr16855.C diff --git a/gcc/coverage.c b/gcc/coverage.c index d4d371e..da7f915 100644 --- a/gcc/coverage.c +++ b/gcc/coverage.c @@ -1054,8 +1054,30 @@ build_init_ctor (tree gcov_info_type) stmt = build_call_expr (init_fn, 1, stmt); append_to_statement_list (stmt, &ctor); - /* Generate a constructor to run it. */ - cgraph_build_static_cdtor ('I', ctor, DEFAULT_INIT_PRIORITY); + /* Generate a constructor to run it (with priority 99). */ + cgraph_build_static_cdtor ('I', ctor, DEFAULT_INIT_PRIORITY - 1); +} + +/* Generate the destructor function to call __gcov_exit. */ + +static void +build_gcov_exit_decl (void) +{ + tree init_fn = build_function_type_list (void_type_node, void_type_node, + NULL); + init_fn = build_decl (BUILTINS_LOCATION, FUNCTION_DECL, + get_identifier ("__gcov_exit"), init_fn); + TREE_PUBLIC (init_fn) = 1; + DECL_EXTERNAL (init_fn) = 1; + DECL_ASSEMBLER_NAME (init_fn); + + /* Generate a call to __gcov_exit (). */ + tree dtor = NULL; + tree stmt = build_call_expr (init_fn, 0); + append_to_statement_list (stmt, &dtor); + + /* Generate a destructor to run it (with priority 99). */ + cgraph_build_static_cdtor ('D', dtor, DEFAULT_INIT_PRIORITY - 1); } /* Create the gcov_info types and object. Generate the constructor @@ -1113,6 +1135,7 @@ coverage_obj_init (void) DECL_NAME (gcov_info_var) = get_identifier (name_buf); build_init_ctor (gcov_info_type); + build_gcov_exit_decl (); return true; } diff --git a/gcc/testsuite/g++.dg/gcov/pr16855.C b/gcc/testsuite/g++.dg/gcov/pr16855.C new file mode 100644 index 0000000..ec72e99 --- /dev/null +++ b/gcc/testsuite/g++.dg/gcov/pr16855.C @@ -0,0 +1,37 @@ +/* { dg-options "-fprofile-arcs -ftest-coverage" } */ +/* { dg-do run { target native } } */ + +#include <iostream> +using namespace std; +class Test { +public: + Test(void){ + cout<< "In Test ctor" << endl; /* count(1) */ + } + ~Test(void){ + cout<< "In Test dtor" << endl; /* count(1) */ + } +}T1; + +void uncalled(void){ + cout<< "In uncalled" << endl; /* count(#####) */ +} +int main(void){ +// Test T2; +cout<< "In main" << endl; /* count(1) */ +return 0; +} + +#include <stdio.h> + +__attribute__((constructor)) +static void construct_navigationBarImages() { + fprintf (stderr, "((construct_navigationBarImages))"); /* count(1) */ +} + +__attribute__((destructor)) +static void destroy_navigationBarImages() { + fprintf (stderr, "((destroy_navigationBarImages))"); /* count(1) */ +} + +/* { dg-final { run-gcov branches { -b pr16855.C } } } */ diff --git a/libgcc/libgcov-driver.c b/libgcc/libgcov-driver.c index d51397e..84471bd 100644 --- a/libgcc/libgcov-driver.c +++ b/libgcc/libgcov-driver.c @@ -872,8 +872,8 @@ struct gcov_root __gcov_root; struct gcov_master __gcov_master = {GCOV_VERSION, 0}; -static void -gcov_exit (void) +void +__gcov_exit (void) { __gcov_dump_one (&__gcov_root); if (__gcov_root.next) @@ -906,7 +906,6 @@ __gcov_init (struct gcov_info *info) __gcov_master.root->prev = &__gcov_root; __gcov_master.root = &__gcov_root; } - atexit (gcov_exit); } info->next = __gcov_root.list; diff --git a/libgcc/libgcov.h b/libgcc/libgcov.h index 80f13e2..113f877 100644 --- a/libgcc/libgcov.h +++ b/libgcc/libgcov.h @@ -235,6 +235,9 @@ extern void __gcov_dump_one (struct gcov_root *) ATTRIBUTE_HIDDEN; /* Register a new object file module. */ extern void __gcov_init (struct gcov_info *) ATTRIBUTE_HIDDEN; +/* GCOV exit function registered via a static destructor. */ +extern void __gcov_exit (void) ATTRIBUTE_HIDDEN; + /* Called before fork, to avoid double counting. */ extern void __gcov_flush (void) ATTRIBUTE_HIDDEN; -- 2.9.2