From 0b27c27d0d3060171876736f05c39f9c86a65d3e Mon Sep 17 00:00:00 2001 From: Christian Biesinger Date: Thu, 1 Aug 2019 17:22:28 -0500 Subject: [PATCH] Add block['var'] accessor Currently we support iteration on blocks; this patch extends that to make subscript access work as well. gdb/ChangeLog: 2019-08-05 Christian Biesinger * NEWS: Mention dictionary access on blocks. * python/py-block.c (blpy_getitem): New function. (block_object_as_mapping): New struct. (block_object_type): Use new struct for tp_as_mapping field. gdb/doc/ChangeLog: 2019-08-05 Christian Biesinger * python.texi (Blocks In Python): Document dictionary access on blocks. gdb/testsuite/ChangeLog: 2019-08-05 Christian Biesinger * gdb.python/py-block.exp: Test dictionary access on blocks. --- gdb/ChangeLog | 7 +++++ gdb/NEWS | 3 ++ gdb/doc/ChangeLog | 4 +++ gdb/doc/python.texi | 7 ++++- gdb/python/py-block.c | 45 ++++++++++++++++++++++++++- gdb/testsuite/ChangeLog | 4 +++ gdb/testsuite/gdb.python/py-block.exp | 5 +++ 7 files changed, 73 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index da1d636a244..b17b2526ede 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2019-08-05 Christian Biesinger + + * NEWS: Mention dictionary access on blocks. + * python/py-block.c (blpy_getitem): New function. + (block_object_as_mapping): New struct. + (block_object_type): Use new struct for tp_as_mapping field. + 2019-08-05 Christian Biesinger * objfiles.h (objfile): Add a comment describing partial symbols. diff --git a/gdb/NEWS b/gdb/NEWS index da641cb5980..b4c59e4410d 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -47,6 +47,9 @@ ** gdb.Objfile has new methods 'lookup_global_symbol' and 'lookup_static_symbol' to lookup a symbol from this objfile only. + ** gdb.Block now supports the dictionary syntax for accessing symbols in + this block (e.g. block['local_variable']). + * New commands | [COMMAND] | SHELL_COMMAND diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 95fd22cddd0..6faf5f359d6 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,7 @@ +2019-08-05 Christian Biesinger + + * python.texi (Blocks In Python): Document dictionary access on blocks. + 2019-08-03 Philippe Waroquiers * gdb.texinfo (Symbols): Document new args -dirname and -basename diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi index 3fdccd5e435..832283dede8 100644 --- a/gdb/doc/python.texi +++ b/gdb/doc/python.texi @@ -4722,7 +4722,12 @@ A @code{gdb.Block} is iterable. The iterator returns the symbols should not assume that a specific block object will always contain a given symbol, since changes in @value{GDBN} features and infrastructure may cause symbols move across blocks in a symbol -table. +table. You can also use Python's @dfn{dictionary syntax} to access +variables in this block, e.g.: + +@smallexample +symbol = some_block['variable'] # symbol is of type gdb.Symbol +@end smallexample The following block-related functions are available in the @code{gdb} module: diff --git a/gdb/python/py-block.c b/gdb/python/py-block.c index 90140ebc34a..4dc47ff169d 100644 --- a/gdb/python/py-block.c +++ b/gdb/python/py-block.c @@ -224,6 +224,43 @@ blpy_is_static (PyObject *self, void *closure) Py_RETURN_FALSE; } +/* Given a string, returns the gdb.Symbol representing that symbol in this + block. If such a symbol does not exist, returns NULL with a Python + exception. */ + +static PyObject * +blpy_getitem (PyObject *self, PyObject *key) +{ + const struct block *block; + + BLPY_REQUIRE_VALID (self, block); + + gdb::unique_xmalloc_ptr name = python_string_to_host_string (key); + if (name == nullptr) + return nullptr; + + lookup_name_info lookup_name (name.get(), symbol_name_match_type::FULL); + + /* We use ALL_BLOCK_SYMBOLS_WITH_NAME instead of block_lookup_symbol so + that we can look up symbols irrespective of the domain, matching the + iterator. It would be confusing if the iterator returns symbols you + can't find via getitem. */ + struct block_iterator iter; + struct symbol *sym = nullptr; + ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym) + { + /* Just stop at the first match */ + break; + } + + if (sym == nullptr) + { + PyErr_SetObject (PyExc_KeyError, key); + return nullptr; + } + return symbol_to_symbol_object (sym); +} + static void blpy_dealloc (PyObject *obj) { @@ -440,6 +477,12 @@ static gdb_PyGetSetDef block_object_getset[] = { { NULL } /* Sentinel */ }; +static PyMappingMethods block_object_as_mapping = { + NULL, + blpy_getitem, + NULL +}; + PyTypeObject block_object_type = { PyVarObject_HEAD_INIT (NULL, 0) "gdb.Block", /*tp_name*/ @@ -453,7 +496,7 @@ PyTypeObject block_object_type = { 0, /*tp_repr*/ 0, /*tp_as_number*/ 0, /*tp_as_sequence*/ - 0, /*tp_as_mapping*/ + &block_object_as_mapping, /*tp_as_mapping*/ 0, /*tp_hash */ 0, /*tp_call*/ 0, /*tp_str*/ diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 236c0e2442e..1a2cb0be18e 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2019-08-05 Christian Biesinger + + * gdb.python/py-block.exp: Test dictionary access on blocks. + 2019-08-05 Simon Marchi PR gdb/24863 diff --git a/gdb/testsuite/gdb.python/py-block.exp b/gdb/testsuite/gdb.python/py-block.exp index 20d3968c046..6be1abe7ae0 100644 --- a/gdb/testsuite/gdb.python/py-block.exp +++ b/gdb/testsuite/gdb.python/py-block.exp @@ -43,6 +43,11 @@ gdb_test "python print (block)" "" "check block not No gdb_test "python print (block.function)" "None" "first anonymous block" gdb_test "python print (block.start)" "${decimal}" "check start not None" gdb_test "python print (block.end)" "${decimal}" "check end not None" +gdb_test "python print (block\['f'\].name == 'f')" "True" "check variable access" +gdb_test "python print (block\['nonexistent'\])" ".*KeyError: 'nonexistent'.*" \ + "check nonexistent variable" +gdb_test "python print (block\[42\])" ".*TypeError: Expected a string.*" \ + "check non-string key" # Test global/static blocks gdb_py_test_silent_cmd "python frame = gdb.selected_frame()" "Get Frame" 0 -- 2.30.2