On Thu, 2022-01-06 at 08:53 -0500, David Malcolm wrote: > On Sun, 2021-12-19 at 22:30 +0100, Marc Nieper-Wißkirchen wrote: > > This patch fixes a memory leak in the pass manager. In the existing > > code, > > the m_name_to_pass_map is allocated in > > pass_manager::register_pass_name, but > > never deallocated. This is fixed by adding a deletion in > > pass_manager::~pass_manager. Moreover the string keys in > > m_name_to_pass_map are > > all dynamically allocated. To free them, this patch adds a new hash > > trait for > > string hashes that are to be freed when the corresponding hash entry > > is removed. > > > > This fix is particularly relevant for using GCC as a library through > > libgccjit. > > The memory leak also occurs when libgccjit is instructed to use an > > external > > driver. > > > > Before the patch, compiling the hello world example of libgccjit with > > the external driver under Valgrind shows a loss of 12,611 (48 direct) > > bytes. After the patch, no memory leaks are reported anymore. > > (Memory leaks occurring when using the internal driver are mostly in > > the driver code in gcc/gcc.c and have to be fixed separately.) > > > > The patch has been tested by fully bootstrapping the compiler with > > the > > frontends C, C++, Fortran, LTO, ObjC, JIT and running the test suite > > under a x86_64-pc-linux-gnu host. > > Thanks for the patch. > > It looks correct to me, given that pass_manager::register_pass_name > does an xstrdup and puts the result in the map. > > That said: > - I'm not officially a reviewer for this part of gcc (though I probably > touched this code last) > - is it cleaner to instead change m_name_to_pass_map's key type from > const char * to char *, to convey that the map "owns" the name? That > way we probably wouldn't need struct typed_const_free_remove, and (I > hope) works better with the type system.
[...snip...] > > > diff --git a/gcc/passes.c b/gcc/passes.c > > index 4bea6ae5b6a..0c70ece5321 100644 > > --- a/gcc/passes.c > > +++ b/gcc/passes.c [...snip...] > > @@ -1943,7 +1944,7 @@ pass_manager::dump_profile_report () const > > " |in count |out > > prob " > > "|in count |out prob " > > "|size |time |\n"); > > - > > + > > for (int i = 1; i < passes_by_id_size; i++) > > if (profile_record[i].run) > > { > ...and there's a stray whitespace change here (in pass_manager::dump_profile_report), which probably shouldn't be in the patch. Dave