diff options
author | Pedro Alves <pedro@palves.net> | 2022-08-05 16:12:56 +0200 |
---|---|---|
committer | Tom de Vries <tdevries@suse.de> | 2022-08-05 16:12:56 +0200 |
commit | 377c3a9c91785d5df5c0d96121160e6210204cc0 (patch) | |
tree | 9e161fd592615e7cdc45d2d137926d6453236e90 /gdb/unittests | |
parent | 5ee285ca3e5cca998c76ca1c92927008849ff00e (diff) | |
download | binutils-377c3a9c91785d5df5c0d96121160e6210204cc0.zip binutils-377c3a9c91785d5df5c0d96121160e6210204cc0.tar.gz binutils-377c3a9c91785d5df5c0d96121160e6210204cc0.tar.bz2 |
Introduce gdb::make_function_view
This adds gdb::make_function_view, which lets you create a function
view from a callable without specifying the function_view's template
parameter. For example, this:
auto lambda = [&] (int) { ... };
auto fv = gdb::make_function_view (lambda);
instead of:
auto lambda = [&] (int) { ... };
gdb::function_view<void (int)> fv = lambda;
It is particularly useful if you have a template function with an
optional function_view parameter, whose type depends on the function's
template parameters. Like:
template<typename T>
void my_function (T v, gdb::function_view<void(T)> callback = nullptr);
For such a function, the type of the callback argument you pass must
already be a function_view. I.e., this wouldn't compile:
auto lambda = [&] (int) { ... };
my_function (1, lambda);
With gdb::make_function_view, you can write the call like so:
auto lambda = [&] (int) { ... };
my_function (1, gdb::make_function_view (lambda));
Unit tests included.
Tested by building with GCC 9.4, Clang 10, and GCC 4.8.5, on x86_64
GNU/Linux, and running the unit tests.
Change-Id: I5c4b3b4455ed6f0d8878cf1be189bea3ee63f626
Diffstat (limited to 'gdb/unittests')
-rw-r--r-- | gdb/unittests/function-view-selftests.c | 82 |
1 files changed, 81 insertions, 1 deletions
diff --git a/gdb/unittests/function-view-selftests.c b/gdb/unittests/function-view-selftests.c index 7af0245..726c223 100644 --- a/gdb/unittests/function-view-selftests.c +++ b/gdb/unittests/function-view-selftests.c @@ -61,7 +61,7 @@ struct plus_one_int_func_obj }; static void -run_tests () +test_function_view () { /* A simple lambda. */ auto plus_one_lambda = [] (int val) { return ++val; }; @@ -168,6 +168,86 @@ run_tests () SELF_CHECK (!check_op_eq_null); } +/* A template function where the function_view type is dependent on a + template parameter. */ + +template<typename T> +static int +tmpl_func (T val, gdb::function_view<T (T)> callback) +{ + return callback (val) + 1; +} + +static int +make_fv_test_func (int val) +{ + return val + 1; +} + +/* A function object with const operator(). */ + +struct func_obj_const_op +{ + int operator() (int val) const + { + return val + 1; + } +}; + +/* A function object with non-const operator(). */ + +struct func_obj_non_const_op +{ + int operator() (int val) + { + return val + 1; + } +}; + +static void +test_make_function_view () +{ + /* Function reference. */ + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (make_fv_test_func))); + + /* Function pointer. */ + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (&make_fv_test_func))); + + /* Reference to const and non-const function pointers. */ + typedef int (*func_ptr) (int); + func_ptr ptr = make_fv_test_func; + const func_ptr cptr = make_fv_test_func; + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (ptr))); + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (cptr))); + + /* Lambdas. */ + + auto lambda = [] (int val) -> int { return val + 1; }; + + /* This wouldn't compile, since tmpl_func is a template and its + function_view argument's callable type is a dependent type. The + passed argument must be of the exact type of the function's + parameter. */ + // SELF_CHECK (3 == tmpl_func (1, lambda)); + + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (lambda))); + + /* Regular function objects. */ + + func_obj_non_const_op fobj; + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (fobj))); + + func_obj_const_op cfobj; + SELF_CHECK (3 == tmpl_func (1, gdb::make_function_view (cfobj))); +} + +static void +run_tests () +{ + test_function_view (); + test_make_function_view (); +} + } /* namespace function_view */ } /* namespace selftests */ |