From b7b2e4911328f6b275baafe395a1d2485e158195 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc=20Nieper-Wi=C3=9Fkirchen?= Date: Sun, 19 Dec 2021 22:30:10 +0100 Subject: [PATCH] gcc: pass-manager: Fix memory leak. [PR jit/63854] To: gcc-patches@gcc.gnu.org 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. gcc/ChangeLog: PR jit/63854 * hash-traits.h (struct typed_const_free_remove): New. (struct free_string_hash): New. * pass_manager.h: Use free_string_hash. * passes.cc (pass_manager::register_pass_name): Use free_string_hash. (pass_manager::~pass_manager): Delete allocated m_name_to_pass_map. --- gcc/hash-traits.h | 17 +++++++++++++++++ gcc/pass_manager.h | 3 +-- gcc/passes.cc | 5 +++-- 3 files changed, 21 insertions(+), 4 deletions(-) diff --git a/gcc/hash-traits.h b/gcc/hash-traits.h index b16975cfeb3..bef0bd42d04 100644 --- a/gcc/hash-traits.h +++ b/gcc/hash-traits.h @@ -28,6 +28,11 @@ struct typed_free_remove static inline void remove (Type *p); }; +template +struct typed_const_free_remove +{ + static inline void remove (const Type *p); +}; /* Remove with free. */ @@ -38,6 +43,13 @@ typed_free_remove ::remove (Type *p) free (p); } +template +inline void +typed_const_free_remove ::remove (const Type *p) +{ + free (const_cast (p)); +} + /* Helpful type for removing with delete. */ template @@ -305,6 +317,11 @@ struct ggc_ptr_hash : pointer_hash , ggc_remove {}; template struct ggc_cache_ptr_hash : pointer_hash , ggc_cache_remove {}; +/* Traits for string elements that should be freed when an element is + deleted. */ + +struct free_string_hash : string_hash, typed_const_free_remove {}; + /* Traits for string elements that should not be freed when an element is deleted. */ diff --git a/gcc/pass_manager.h b/gcc/pass_manager.h index 6484d2c8ebc..43484da2700 100644 --- a/gcc/pass_manager.h +++ b/gcc/pass_manager.h @@ -106,7 +106,7 @@ private: private: context *m_ctxt; - hash_map *m_name_to_pass_map; + hash_map *m_name_to_pass_map; /* References to all of the individual passes. These fields are generated via macro expansion. @@ -146,4 +146,3 @@ private: } // namespace gcc #endif /* ! GCC_PASS_MANAGER_H */ - diff --git a/gcc/passes.cc b/gcc/passes.cc index 00f856e0754..36e5b4ac45f 100644 --- a/gcc/passes.cc +++ b/gcc/passes.cc @@ -903,7 +903,7 @@ void pass_manager::register_pass_name (opt_pass *pass, const char *name) { if (!m_name_to_pass_map) - m_name_to_pass_map = new hash_map (256); + m_name_to_pass_map = new hash_map (256); if (m_name_to_pass_map->get (name)) return; /* Ignore plugin passes. */ @@ -1674,6 +1674,7 @@ pass_manager::~pass_manager () GCC_PASS_LISTS #undef DEF_PASS_LIST + delete m_name_to_pass_map; } /* If we are in IPA mode (i.e., current_function_decl is NULL), call @@ -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) { -- 2.32.0