From 1b61f46da5e55bf2df243215f34ffbca4bcf6d9e Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 16 Dec 2019 16:30:49 -0500 Subject: [PATCH] jit: make gdb_object::symtabs an std::forward_list Replace the manual linked list with an std::forward_list, simplifying the memory management. This requires allocating gdb_object with new and free'ing it with delete. gdb/ChangeLog: * jit.c: Include forward_list. (struct gdb_symtab) : Remove field. (struct gdb_object) : Change type to std::forward_list. (jit_object_open_impl): Allocate gdb_object with new. (jit_symtab_open_impl): Adjust to std::forward_list. (finalize_symtab): Don't delete symtab. (jit_object_close_impl): Adjust to std::forward_list. Free gdb_object with delete. --- gdb/ChangeLog | 12 ++++++++++++ gdb/jit.c | 34 ++++++++++++++++------------------ 2 files changed, 28 insertions(+), 18 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 86718ad83e..b70f3fa04f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2019-12-16 Simon Marchi + + * jit.c: Include forward_list. + (struct gdb_symtab) : Remove field. + (struct gdb_object) : Change type to + std::forward_list. + (jit_object_open_impl): Allocate gdb_object with new. + (jit_symtab_open_impl): Adjust to std::forward_list. + (finalize_symtab): Don't delete symtab. + (jit_object_close_impl): Adjust to std::forward_list. Free + gdb_object with delete. + 2019-12-16 Simon Marchi * jit.c (struct gdb_symtab): Add constructor, destructor, diff --git a/gdb/jit.c b/gdb/jit.c index 07767275f5..a731edd870 100644 --- a/gdb/jit.c +++ b/gdb/jit.c @@ -41,6 +41,7 @@ #include "gdb_bfd.h" #include "readline/tilde.h" #include "completer.h" +#include static std::string jit_reader_dir; @@ -481,15 +482,19 @@ struct gdb_symtab /* The source file for this symtab. */ std::string file_name; - - struct gdb_symtab *next = nullptr; }; /* Proxy object for building an object. */ struct gdb_object { - struct gdb_symtab *symtabs; + /* Symtabs of this object. + + This is specifically a linked list, instead of, for example, a vector, + because the pointers are returned to the user's debug info reader. So + it's important that the objects don't change location during their + lifetime (which would happen with a vector of objects getting resized). */ + std::forward_list symtabs; }; /* The type of the `private' data passed around by the callback @@ -521,7 +526,7 @@ jit_object_open_impl (struct gdb_symbol_callbacks *cb) /* CB is not required right now, but sometime in the future we might need a handle to it, and we'd like to do that without breaking the ABI. */ - return XCNEW (struct gdb_object); + return new gdb_object; } /* Readers call into this function to open a new gdb_symtab, which, @@ -534,10 +539,8 @@ jit_symtab_open_impl (struct gdb_symbol_callbacks *cb, { /* CB stays unused. See comment in jit_object_open_impl. */ - gdb_symtab *ret = new gdb_symtab (file_name); - ret->next = object->symtabs; - object->symtabs = ret; - return ret; + object->symtabs.emplace_front (file_name); + return &object->symtabs.front (); } /* Returns true if the block corresponding to old should be placed @@ -774,8 +777,6 @@ finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile) BLOCKVECTOR_BLOCK (bv, STATIC_BLOCK); } } - - delete stab; } /* Called when closing a gdb_objfile. Converts OBJ to a proper @@ -785,7 +786,6 @@ static void jit_object_close_impl (struct gdb_symbol_callbacks *cb, struct gdb_object *obj) { - struct gdb_symtab *i, *j; struct objfile *objfile; jit_dbg_reader_data *priv_data; @@ -795,14 +795,12 @@ jit_object_close_impl (struct gdb_symbol_callbacks *cb, OBJF_NOT_FILENAME); objfile->per_bfd->gdbarch = target_gdbarch (); - j = NULL; - for (i = obj->symtabs; i; i = j) - { - j = i->next; - finalize_symtab (i, objfile); - } + for (gdb_symtab &symtab : obj->symtabs) + finalize_symtab (&symtab, objfile); + add_objfile_entry (objfile, *priv_data); - xfree (obj); + + delete obj; } /* Try to read CODE_ENTRY using the loaded jit reader (if any). -- 2.34.1