From 57a91ca28fa903375bfc829d8f6ad3fb8f34e1b0 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Tue, 30 Jul 2024 10:37:01 -0400 Subject: [PATCH] gdb: some global_block improvements Some refactors around struct global_block, all in one patch because they all tie in together and are relatively trivial. - Make block::global_block() and blockvector::global_block() return `global_block *`, instead of `block *`. There is no cost in doing so, and it's a bit more precise. Callers of these methods that need a `global_block *` won't need to cast themselves. - Add some block::as_global_block methods, as a way to get a `global_block *` from a `block *` when you know it's a global block. This is basically a static cast with an assert. - Move set_compunit_symtab to global_block, since it requires the block to be a global block anyway. Rename to just `set_compunit` (I think that compunit_symtab should just be renamed compunit...). - Move the get_block_compunit_symtab free function to be a method of global_block. - Make global_block::compunit_symtab private and rename. - Simplify initialize_block_iterator. Change-Id: I1667a86b5c1a02d0d460cfad55b5d3d48867583d Approved-By: Tom Tromey --- gdb/block.c | 75 ++++++++++++++++++++------------------------------ gdb/block.h | 48 +++++++++++++++++++++++--------- gdb/buildsym.c | 6 +--- gdb/jit.c | 3 +- 4 files changed, 68 insertions(+), 64 deletions(-) diff --git a/gdb/block.c b/gdb/block.c index acf21e26fc8..d4baaae4a5f 100644 --- a/gdb/block.c +++ b/gdb/block.c @@ -41,13 +41,10 @@ struct block_namespace_info : public allocate_on_obstack struct objfile * block::objfile () const { - const struct global_block *global_block; - if (function () != nullptr) return function ()->objfile (); - global_block = (struct global_block *) this->global_block (); - return global_block->compunit_symtab->objfile (); + return this->global_block ()->compunit ()->objfile (); } /* See block. */ @@ -364,7 +361,7 @@ block::static_block () const /* See block.h. */ -const struct block * +const struct global_block * block::global_block () const { const block *block = this; @@ -372,33 +369,40 @@ block::global_block () const while (block->superblock () != NULL) block = block->superblock (); - return block; + return block->as_global_block (); } /* See block.h. */ -const struct block * -block::function_block () const +struct global_block * +block::as_global_block () { - const block *block = this; + gdb_assert (this->is_global_block ()); - while (block != nullptr && block->function () == nullptr) - block = block->superblock (); + return static_cast(this); +} - return block; +/* See block.h. */ + +const struct global_block * +block::as_global_block () const +{ + gdb_assert (this->is_global_block ()); + + return static_cast(this); } /* See block.h. */ -void -block::set_compunit_symtab (struct compunit_symtab *cu) +const struct block * +block::function_block () const { - struct global_block *gb; + const block *block = this; - gdb_assert (superblock () == NULL); - gb = (struct global_block *) this; - gdb_assert (gb->compunit_symtab == NULL); - gb->compunit_symtab = cu; + while (block != nullptr && block->function () == nullptr) + block = block->superblock (); + + return block; } /* See block.h. */ @@ -416,21 +420,6 @@ block::static_link () const return (struct dynamic_prop *) objfile_lookup_static_link (objfile, this); } -/* Return the compunit of the global block. */ - -static struct compunit_symtab * -get_block_compunit_symtab (const struct block *block) -{ - struct global_block *gb; - - gdb_assert (block->superblock () == NULL); - gb = (struct global_block *) block; - gdb_assert (gb->compunit_symtab != NULL); - return gb->compunit_symtab; -} - - - /* Initialize a block iterator, either to iterate over a single block, or, for static and global blocks, all the included symtabs as well. */ @@ -441,30 +430,26 @@ initialize_block_iterator (const struct block *block, const lookup_name_info *name) { enum block_enum which; - struct compunit_symtab *cu; iter->idx = -1; iter->name = name; - if (block->superblock () == NULL) - { - which = GLOBAL_BLOCK; - cu = get_block_compunit_symtab (block); - } - else if (block->superblock ()->superblock () == NULL) - { - which = STATIC_BLOCK; - cu = get_block_compunit_symtab (block->superblock ()); - } + if (block->is_global_block ()) + which = GLOBAL_BLOCK; + else if (block->is_static_block ()) + which = STATIC_BLOCK; else { iter->d.block = block; + /* A signal value meaning that we're iterating over a single block. */ iter->which = FIRST_LOCAL_BLOCK; return; } + compunit_symtab *cu = block->global_block ()->compunit (); + /* If this is an included symtab, find the canonical includer and use it instead. */ while (cu->user != NULL) diff --git a/gdb/block.h b/gdb/block.h index ae676c4ba67..c3babad52f3 100644 --- a/gdb/block.h +++ b/gdb/block.h @@ -264,25 +264,26 @@ struct block : public allocate_on_obstack return sup->is_global_block (); } - /* Return the static block associated with block. */ + /* Return the global block associated with block. */ - const struct block *global_block () const; + const struct global_block *global_block () const; /* Return true if this block is a global block. */ bool is_global_block () const { return superblock () == nullptr; } + /* Return this block as a global_block. This block must be a global + block. */ + struct global_block *as_global_block (); + const struct global_block *as_global_block () const; + /* Return the function block for this block. Returns nullptr if there is no enclosing function, i.e., if this block is a static or global block. */ const struct block *function_block () const; - /* Set the compunit of this block, which must be a global block. */ - - void set_compunit_symtab (struct compunit_symtab *); - /* Return a property to evaluate the static link associated to this block. @@ -346,13 +347,31 @@ private: }; /* The global block is singled out so that we can provide a back-link - to the compunit symtab. */ + to the compunit. */ struct global_block : public block { - /* This holds a pointer to the compunit symtab holding this block. */ + /* Set the compunit of this global block. + + The compunit must not have been set previously. */ + void set_compunit (compunit_symtab *cu) + { + gdb_assert (m_compunit == nullptr); + m_compunit = cu; + } + + /* Return the compunit of this global block. - struct compunit_symtab *compunit_symtab = nullptr; + The compunit must have been set previously. */ + compunit_symtab *compunit () const + { + gdb_assert (m_compunit != nullptr); + return m_compunit; + } + +private: + /* This holds a pointer to the compunit holding this block. */ + compunit_symtab *m_compunit = nullptr; }; struct blockvector @@ -394,12 +413,15 @@ struct blockvector { return m_num_blocks; } /* Return the global block of this blockvector. */ - struct block *global_block () - { return this->block (GLOBAL_BLOCK); } + struct global_block *global_block () + { return static_cast (this->block (GLOBAL_BLOCK)); } /* Const version of the above. */ - const struct block *global_block () const - { return this->block (GLOBAL_BLOCK); } + const struct global_block *global_block () const + { + return static_cast + (this->block (GLOBAL_BLOCK)); + } /* Return the static block of this blockvector. */ struct block *static_block () diff --git a/gdb/buildsym.c b/gdb/buildsym.c index 1c762ad81bf..02d6848f3a4 100644 --- a/gdb/buildsym.c +++ b/gdb/buildsym.c @@ -951,11 +951,7 @@ buildsym_compunit::end_compunit_symtab_with_blockvector cu->set_producer (m_producer); cu->set_blockvector (blockvector); - { - struct block *b = blockvector->global_block (); - - b->set_compunit_symtab (cu); - } + blockvector->global_block ()->set_compunit (cu); cu->set_macro_table (release_macros ()); diff --git a/gdb/jit.c b/gdb/jit.c index d4513325190..89c967db615 100644 --- a/gdb/jit.c +++ b/gdb/jit.c @@ -613,6 +613,7 @@ finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile) new_block = new (&objfile->objfile_obstack) global_block; else new_block = new (&objfile->objfile_obstack) block; + new_block->set_multidict (mdict_create_linear (&objfile->objfile_obstack, NULL)); new_block->set_superblock (block_iter); @@ -624,7 +625,7 @@ finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile) bv->set_block (i, new_block); if (i == GLOBAL_BLOCK) - new_block->set_compunit_symtab (cust); + new_block->as_global_block ()->set_compunit (cust); } /* Fill up the superblock fields for the real blocks, using the -- 2.39.5