Install some sanity checks that sibling DIE offsets are not beyond the
defined limits of the DWARF input buffer in read_partial_die and skip_one_die.
2014-03-20 Keith Seitz <keiths@redhat.com>
PR gdb/15827
* dwarf2read.c (skip_one_die): Check that all relative-offset
sibling DIEs fall within range of the current reader's buffer.
(read_partial_die): Likewise.
2014-03-20 Keith Seitz <keiths@redhat.com>
PR gdb/15827
* gdb.dwarf2/corrupt.c: New file.
* gdb.dwarf2/corrupt.exp: New file.
[forgot to commit/push these with previous push]
If lookup_symbol_file tries to locate a member variable with NULL name:
/* A simple lookup failed. Check if the symbol was defined in
a base class. */
cleanup = make_cleanup (null_cleanup, NULL);
/* Find the name of the class and the name of the method,
variable, etc. */
prefix_len = cp_entire_prefix_len (name);
/* If no prefix was found, search "this". */
if (prefix_len == 0)
{
struct type *type;
struct symbol *this;
this = lookup_language_this (language_def (language_cplus), block);
if (this == NULL)
{
do_cleanups (cleanup);
return NULL;
}
type = check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (this)));
klass = xstrdup (TYPE_NAME (type));
nested = xstrdup (name);
}
TYPE_NAME (type) is NULL, so xstrdup (NULL) and boom!
This can happen, e.g., with clang++. See testsuite/gdb.cp/namelessclass.exp
or the bugzilla report.
This patch simply adds a fencepost against this case, allowing the caller
of lookup_symbol_file to search other blocks for the right symbol.
If lookup_symbol_file tries to locate a member variable with NULL name:
/* A simple lookup failed. Check if the symbol was defined in
a base class. */
cleanup = make_cleanup (null_cleanup, NULL);
/* Find the name of the class and the name of the method,
variable, etc. */
prefix_len = cp_entire_prefix_len (name);
/* If no prefix was found, search "this". */
if (prefix_len == 0)
{
struct type *type;
struct symbol *this;
this = lookup_language_this (language_def (language_cplus), block);
if (this == NULL)
{
do_cleanups (cleanup);
return NULL;
}
type = check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (this)));
klass = xstrdup (TYPE_NAME (type));
nested = xstrdup (name);
}
TYPE_NAME (type) is NULL, so xstrdup (NULL) and boom!
This can happen, e.g., with clang++. See testsuite/gdb.cp/namelessclass.exp
or the bugzilla report.
This patch simply adds a fencepost against this case, allowing the caller
of lookup_symbol_file to search other blocks for the right symbol.
* lib/gdbserver-support.exp (gdbserver_default_get_remote_address):
Add comment.
(gdbserver_default_get_comm_port): New function.
(gdbserver_start): Check if board file provided
"gdbserver,get_comm_port" and use it if so.
* boards/native-stdio-gdbserver.exp (sockethost): Set to "".
(gdb,socketport): Set to "stdio".
(gdbserver,get_comm_port): Set to ${board}_get_comm_port.
(stdio_gdbserver_template): Delete.
(${board}_get_remote_address): Update.
(${board}_build_remote_cmd): Delete.
(${board}_get_comm_port): New function.
(${board}_spawn): Update.
* boards/remote-stdio-gdbserver.exp (${board}_build_remote_cmd):
Delete.
(${board}_get_remote_address): Update.
(${board}_get_comm_port): New function.
https://sourceware.org/ml/gdb-patches/2014-04/msg00210.html
Improve the regexp used in the memattr.exp test so allow for different
memory regions (.data / .bss) being laid out in different orders.
gdb/testsuite/ChangeLog:
* gdb.base/memattr.exp: Improve regexps to handle memory regions
appearing in any order.
This test uses a simple custom elf loader, implemented in
gdb.base/sym-file-loader.h|c. This loader doesn't have a dlclose-like
function today, but I'll need one. But, I found that the guts of the
loader are exposed too much to the client, making the interface more
complicated than necessary. It's simpler if the loader just exports a
few dlopen/dlsym -style functions. That's what this patch does.
Tested on x86_86 Fedora 17, native and gdbserver.
gdb/testsuite/
2014-04-15 Pedro Alves <palves@redhat.com>
* gdb.base/sym-file-loader.h: Move inclusion of <inttypes.h>,
<ansidecl.h>, <elf/common.h> and <elf/external.h> to
sym-file-loader.c.
(Elf_External_Phdr, Elf_External_Ehdr, Elf_External_Shdr)
(Elf_External_Sym, Elf_Addr, GET, GETADDR, struct segment): Move
to sym-file-loader.c.
(struct library): Forward declare.
(load_shlib, lookup_function): Change prototypes.
(find_shstrtab, find_strtab, find_shdr, find_symtab)
(translate_offset): Remove declarations.
(get_text_addr): New declaration.
* gdb.base/sym-file-loader.c: Move inclusion of <inttypes.h>,
<ansidecl.h>, <elf/common.h> and <elf/external.h> here from
sym-file-loader.h.
(Elf_External_Phdr, Elf_External_Ehdr, Elf_External_Shdr)
(Elf_External_Sym, Elf_Addr, GET, GETADDR, struct segment): Move
here from sym-file-loader.h.
(struct library): New structure.
(load_shlib, lookup_function): Change prototypes and adjust to
work with a struct library.
(find_shstrtab, find_strtab, find_shdr, find_symtab)
(translate_offset): Make static.
(get_text_addr): New function.
* gdb.base/sym-file-main.c (main): Adjust to new loader interface.
SELF_LINK, not SELK_LINK...
gdb/testsuite/
2014-04-15 Pedro Alves <palves@redhat.com>
* gdb.base/sym-file-loader.c: Fix typo. SELF_LINK, not SELK_LINK.
The main issue here is that this test passes the host's absolute path
to the library to load to the "dlopen"-like routine, which doesn't
work when either the target or the host are remote, unless a shared
filesystem has been set up.
Tests that dynamically load a library solve this by dlopen'ing by
basename, and setting rpath to $ORIGIN. See gdb_compile.
This test doesn't use dlopen, but instead uses its own simple elf
loader. The fix is to pass this loader the library basename, and
teach it to look up the library by basename in the executable's
directory as well, i.e., assuming/emulating RPATH=$ORIGIN.
Tested on x86_64 Fedora 17, native and gdbserver.
I looked around in the web to figure out Linux's /proc/self/exe
equivalents in other ELF OSs. I think I covered all relevant, but if
not, I think it'll be simple enough to add more. (Note the test is
skipped on non-ELF targets.)
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/testsuite/
2014-04-15 Pedro Alves <palves@redhat.com>
* gdb.base/sym-file-loader.c: Include <limits.h>.
(SELF_LINK): New define.
(get_origin): New function.
(load_shlib): Use it.
* gdb.base/sym-file.exp: Don't early return if the target is
remote. Use runto_main, and issue fail is that fails. Use
gdb_load_shlibs.
(shlib_name): Delete.
(lib_so, lib_syms, lib_dlopen): New globals. Use them throughout.
Remove regex characters from test message, and don't refer to
breakpoint numbers in test messages (subsequent patches will add more
breakpoints, changing these numbers). Result:
-PASS: gdb.base/sym-file.exp: add-symbol-file .*sym-file-lib\.so addr
+PASS: gdb.base/sym-file.exp: add-symbol-file sym-file-lib.so addr
-PASS: gdb.base/sym-file.exp: check if Breakpoint 2 is pending.
-PASS: gdb.base/sym-file.exp: check if Breakpoint 3 is pending.
+PASS: gdb.base/sym-file.exp: breakpoint at foo is pending
+PASS: gdb.base/sym-file.exp: breakpoint at bar is pending
gdb/testsuite/
2014-04-15 Pedro Alves <palves@redhat.com>
* gdb.base/sym-file.exp: Remove regex characters from test
message. Don't refer to breakpoint numbers in test messages.
PR c++/16253.
symbol_matches_domain was permitting searches for a VAR_DOMAIN
symbol to also match STRUCT_DOMAIN symbols for languages like C++
where STRUCT_DOMAIN symbols also define a typedef of the same name,
e.g., "struct foo {}" introduces a typedef of the name "foo".
Problems occur if there exists both a VAR_DOMAIN and STRUCT_DOMAIN
symbol of the same name. Then it is essentially a race between which
symbol is found first. The other symbol is obscurred.
[This is a relatively common idiom: enum e { ... } e;]
This patchset moves this "language defines a typedef" logic to
lookup_symbol[_in_language], looking first for a symbol in the given
domain and falling back to searching STRUCT_DOMAIN when/if appropriate.
2014-04-14 Keith Seitz <keiths@redhat.com>
PR c++/16253
* ada-lang.c (ada_symbol_matches_domain): Moved here and renamed
from symbol_matches_domain in symtab.c. All local callers
of symbol_matches_domain updated.
(standard_lookup): If DOMAIN is VAR_DOMAIN and no symbol is found,
search STRUCT_DOMAIN.
(ada_find_any_type_symbol): Do not search STRUCT_DOMAIN
independently. standard_lookup will do that automatically.
* cp-namespace.c (cp_lookup_symbol_nonlocal): Explain when/why
VAR_DOMAIN searches may return a STRUCT_DOMAIN match.
(cp_lookup_symbol_in_namespace): Likewise.
If no VAR_DOMAIN symbol is found, search STRUCT_DOMAIN.
(cp_lookup_symbol_exports): Explain when/why VAR_DOMAIN searches
may return a STRUCT_DOMAIN match.
(lookup_symbol_file): Search for the class name in STRUCT_DOMAIN.
* cp-support.c: Include language.h.
(inspect_type): Explicitly search STRUCT_DOMAIN before searching
VAR_DOMAIN.
* psymtab.c (match_partial_symbol): Compare the requested
domain with the symbol's domain directly.
(lookup_partial_symbol): Likewise.
* symtab.c (lookup_symbol_in_language): Explain when/why
VAR_DOMAIN searches may return a STRUCT_DOMAIN match.
If no VAR_DOMAIN symbol is found, search STRUCT_DOMAIN for
appropriate languages.
(symbol_matches_domain): Renamed `ada_symbol_matches_domain'
and moved to ada-lang.c
(lookup_block_symbol): Explain that this function only returns
symbol matching the requested DOMAIN.
Compare the requested domain with the symbol's domain directly.
(iterate_over_symbols): Compare the requested domain with the
symbol's domain directly.
* symtab.h (symbol_matches_domain): Remove.
2014-04-14 Keith Seitz <keiths@redhat.com>
PR c++/16253
* gdb.cp/var-tag.cc: New file.
* gdb.cp/var-tag.exp: New file.
* gdb.dwarf2/dw2-ada-ffffffff.exp: Set the language to C++.
* gdb.dwarf2/dw2-anon-mptr.exp: Likewise.
* gdb.dwarf2/dw2-double-set-die-type.exp: Likewise.
* gdb.dwarf2/dw2-inheritance.exp: Likewise.
This adds support for the C++11 "enum class" feature. This is
PR c++/15246.
I chose to use the existing TYPE_DECLARED_CLASS rather than introduce
a new type code. This seemed both simple and clear to me.
I made overloading support for the new enum types strict. This is how
it works in C++; and it didn't seem like an undue burden to keep this,
particularly because enum constants are printed symbolically by gdb.
Built and regtested on x86-64 Fedora 20.
2014-04-14 Tom Tromey <tromey@redhat.com>
PR c++/15246:
* c-exp.y (type_aggregate_p): New function.
(qualified_name, classify_inner_name): Use it.
* c-typeprint.c (c_type_print_base): Handle TYPE_DECLARED_CLASS
and TYPE_TARGET_TYPE of an enum type.
* dwarf2read.c (read_enumeration_type): Set TYPE_DECLARED_CLASS on
an enum type.
(determine_prefix) <case DW_TAG_enumeration_type>: New case;
handle TYPE_DECLARED_CLASS.
* gdbtypes.c (rank_one_type): Handle TYPE_DECLARED_CLASS on enum
types.
* gdbtypes.h (TYPE_DECLARED_CLASS): Update comment.
* valops.c (enum_constant_from_type): New function.
(value_aggregate_elt): Use it.
* cp-namespace.c (cp_lookup_nested_symbol): Handle
TYPE_CODE_ENUM.
2014-04-14 Tom Tromey <tromey@redhat.com>
* gdb.cp/classes.exp (test_enums): Handle underlying type.
* gdb.dwarf2/enum-type.exp: Add test for enum with underlying
type.
* gdb.cp/enum-class.exp: New file.
* gdb.cp/enum-class.cc: New file.
While working on another patch I realized that value_aggregate_elt's
"name" parameter ought to be const. This patch implements this.
2014-04-14 Tom Tromey <tromey@redhat.com>
* valops.c (value_aggregate_elt, value_struct_elt_for_reference)
(value_namespace_elt, value_maybe_namespace_elt): Make "name"
const.
* value.h (value_aggregate_elt): Update.
DWARF allows an enumeration type to have a DW_AT_type. GDB doesn't
recognize this, but there is a patch to change GCC to emit it, and a
DWARF proposal to further allow an enum type with a DW_AT_type to omit
the DW_AT_byte_size. This patch changes gdb to implement this.
Built and regtested on x86-64 Fedora 20.
2014-04-14 Tom Tromey <tromey@redhat.com>
* dwarf2read.c (read_enumeration_type): Handle DW_AT_type.
2014-04-14 Tom Tromey <tromey@redhat.com>
* gdb.dwarf2/enum-type.exp: New file.
The dwarf attribute DW_AT_count specifies the elements of a subrange.
This test covers subranges with present count but absent upper bound
attribute, both with static and dynamic attribute values.
testsuite/ChangeLog:
* gdb.dwarf2/count.exp: New file.
The c99 standard in "6.5.3.4 The sizeof operator" states:
If the type of the operand is a variable length array type, the operand
is evaluated;[...]
This patch mirrors the following c99 semantic in gdb:
1| int vla[n][m];
2| int i = 1;
3| sizeof(vla[i++][0]); // No sideffect
4| assert (i == 1);
5| sizeof(vla[i++]); // With sideffect
6| assert (i == 2);
Note: ptype/whatis still do not allow any sideeffects.
This patch was motivated by:
https://sourceware.org/ml/gdb-patches/2014-01/msg00732.html
gdb/ChangeLog:
* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
(evaluate_subexp_standard): Pass noside argument.
(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
if noside equals EVAL_NORMAL. If the subscript yields a vla type
re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.
testsuite/ChangeLog:
* gdb.base/vla-sideeffect.c: New file.
* gdb.base/vla-sideeffect.exp: New file.
A variable location might be a constant value and therefore no inferior memory
access is needed to read the content. In this case try to resolve the type
bounds.
gdb/ChangeLog:
* findvar.c (default_read_var_value): Resolve dynamic bounds if location
points to a constant blob.
This patch adds support for DW_AT_count as requested in the code review:
https://sourceware.org/ml/gdb-patches/2013-11/msg00200.html
gdb/ChangeLog:
* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
property and store it as the high bound and flag the range accordingly.
* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
* gdbtypes.h (enum range_flags): New enum.
(struct range_bounds): Add flags member.
1| void foo (size_t n) {
2| int vla[n];
3| }
Given the following expression
(gdb) ptype &vla
Gdb evaluates the expression with EVAL_AVOID_SIDE_EFFECTS and thus
does not resolve the bounds information and misinterprets the high
bound as a constant. The current output is:
type = int (*)[1289346]
this patch deals with this case and prints:
type = int (*)[variable length]
instead.
gdb/ChangeLog:
* c-typeprint.c (c_type_print_varspec_suffix): Added
check for not yet resolved high bound. If unresolved, print
"variable length" string to the console instead of random
length.
Constructing a value based on a type and address might change the type
of the newly constructed value. Thus re-fetch type via value_type to ensure
we have the correct type at hand.
gdb/ChangeLog
* ada-lang.c (ada_value_primitive_packed_val): Re-fetch type from value.
(ada_template_to_fixed_record_type_1): Likewise.
(ada_to_fixed_type_1): Likewise.
* cp-valprint.c (cp_print_value_fields_rtti): Likewise.
(cp_print_value): Likewise.
* d-valprint.c (dynamic_array_type): Likewise.
* findvar.c (address_of_variable): Likewise.
* jv-valprint.c (java_value_print): Likewise.
* valops.c (value_ind): Likewise.
* value.c (coerce_ref): Likewise.
This patch enables the sizeof operator for indirections:
1| void foo (size_t n) {
2| int vla[n];
3| int *vla_ptr = &vla;
4| }
(gdb) p sizeof(*vla_ptr)
yields sizeof (size_t) * n.
gdb/ChangeLog:
* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
value and retrieve the dynamic type size.
In C99 the sizeof operator computes the size of a variable length array
at runtime (6.5.3.4 The sizeof operator). This patch reflects the semantic
change in the debugger.
We now are able to get the size of a vla:
1| void foo (size_t n) {
2| int vla[n];
3| }
(gdb) p sizeof(vla)
yields N * sizeof(int).
gdb/ChangeLog:
* eval.c (evaluate_subexp_for_sizeof) <OP_VAR_VALUE>: If the type
passed to sizeof is dynamic evaluate the argument to compute the length.
The dwarf standard allow certain attributes to be expressed as dwarf
expressions rather than constants. For instance upper-/lowerbound attributes.
In case of a c99 variable length array the upperbound is a dynamic attribute.
With this change c99 vla behave the same as with static arrays.
1| void foo (size_t n) {
2| int ary[n];
3| memset(ary, 0, sizeof(ary));
4| }
(gdb) print ary
$1 = {0 <repeats 42 times>}
gdb/ChangeLog:
* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
(dwarf2_evaluate_property): New function.
* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
* dwarf2read.c (attr_to_dynamic_prop): New function.
(read_subrange_type): Use attr_to_dynamic_prop to read high bound
attribute.
* gdbtypes.c: Include dwarf2loc.h.
(is_dynamic_type): New function.
(resolve_dynamic_type): New function.
(resolve_dynamic_bounds): New function.
(get_type_length): New function.
(check_typedef): Use get_type_length to compute type length.
* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
(TYPE_LOW_BOUND_KIND): New macro.
(is_dynamic_type): New function prototype.
* value.c (value_from_contents_and_address): Call resolve_dynamic_type
to resolve dynamic properties of the type. Update comment.
* valops.c (get_value_at, value_at, value_at_lazy): Update comment.
Clang defaults this warning to an error, breaking the build & causing
these tests not to run.
gdb/testsuite/
* gdb.mi/non-stop.c: Add return value for non-void function return
statement.
* gdb.threads/staticthreads.c: Ditto.
* guile/scm-value.c (gdbscm_value_dynamic_type): Use coerce_ref to
dereference TYPE_CODE_REF values.
testsuite/
* gdb.guile/scm-value.c: Improve test case.
* gdb.guile/scm-value.exp: Add new test.
This reverts the following patch series, as they cause some regresssions.
commit 37c1ab67a3
type: add c99 variable length array support
gdb/
* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
(dwarf2_evaluate_property): New function.
* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
* dwarf2read.c (attr_to_dynamic_prop): New function.
(read_subrange_type): Use attr_to_dynamic_prop to read high bound
attribute.
* gdbtypes.c: Include dwarf2loc.h.
(is_dynamic_type): New function.
(resolve_dynamic_type): New function.
(resolve_dynamic_bounds): New function.
(get_type_length): New function.
(check_typedef): Use get_type_length to compute type length.
* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
(TYPE_LOW_BOUND_KIND): New macro.
(is_dynamic_type): New function prototype.
* value.c (value_from_contents_and_address): Call resolve_dynamic_type
to resolve dynamic properties of the type. Update comment.
* valops.c (get_value_at, value_at, value_at_lazy): Update comment.
commit 26cb189f8b
vla: enable sizeof operator to work with variable length arrays
gdb/
* eval.c (evaluate_subexp_for_sizeof) <OP_VAR_VALUE>: If the type
passed to sizeof is dynamic evaluate the argument to compute the length.
commit 04b19544ef
vla: enable sizeof operator for indirection
gdb/
* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
value and retrieve the dynamic type size.
commit bcd629a44f
vla: update type from newly created value
gdb/
* ada-lang.c (ada_value_primitive_packed_val): Re-fetch type from value.
(ada_template_to_fixed_record_type_1): Likewise.
(ada_to_fixed_type_1): Likewise.
* cp-valprint.c (cp_print_value_fields_rtti): Likewise.
(cp_print_value): Likewise.
* d-valprint.c (dynamic_array_type): Likewise.
* eval.c (evaluate_subexp_with_coercion): Likewise.
* findvar.c (address_of_variable): Likewise.
* jv-valprint.c (java_value_print): Likewise.
* valops.c (value_ind): Likewise.
* value.c (coerce_ref): Likewise.
commit b86138fb04
vla: print "variable length" for unresolved dynamic bounds
gdb/
* c-typeprint.c (c_type_print_varspec_suffix): Added
check for not yet resolved high bound. If unresolved, print
"variable length" string to the console instead of random
length.
commit e1969afbd4
vla: support for DW_AT_count
gdb/
* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
property and store it as the high bound and flag the range accordingly.
* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
* gdbtypes.h (enum range_flags): New enum.
(struct range_bounds): Add flags member.
commit 92b09522dc
vla: resolve dynamic bounds if value contents is a constant byte-sequence
gdb/
* findvar.c (default_read_var_value): Resolve dynamic bounds if location
points to a constant blob.
commit 3bce82377f
vla: evaluate operand of sizeof if its type is a vla
gdb/
* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
(evaluate_subexp_standard): Pass noside argument.
(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
if noside equals EVAL_NORMAL. If the subscript yields a vla type
re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.
gdb/testsuite
* gdb.base/vla-sideeffect.c: New file.
* gdb.base/vla-sideeffect.exp: New file.
commit 504f34326e
test: cover subranges with present DW_AT_count attribute
gdb/testsuite/
* gdb.dwarf2/count.exp: New file.
commit 1a237e0ee5
test: multi-dimensional c99 vla.
gdb/testsuite/
* gdb.base/vla-multi.c: New file.
* gdb.base/vla-multi.exp: New file.
commit 024e13b46f
test: evaluate pointers to C99 vla correctly.
gdb/testsuite/
* gdb.base/vla-ptr.c: New file.
* gdb.base/vla-ptr.exp: New file.
commit c8655f75e2
test: basic c99 vla tests for C primitives
gdb/testsuite/
* gdb.base/vla-datatypes.c: New file.
* gdb.base/vla-datatypes.exp: New file.
commit 58a84dcf29
test: add mi vla test
gdb/testsuite/
* gdb.mi/mi-vla-c99.exp: New file.
* gdb.mi/vla.c: New file.
The dwarf attribute DW_AT_count specifies the elements of a subrange.
This test covers subranges with present count but absent upper bound
attribute, both with static and dynamic attribute values.
testsuite:
* gdb.dwarf2/count.exp: New file.
The c99 standard in "6.5.3.4 The sizeof operator" states:
If the type of the operand is a variable length array type, the operand
is evaluated;[...]
This patch mirrors the following c99 semantic in gdb:
1| int vla[n][m];
2| int i = 1;
3| sizeof(vla[i++][0]); // No sideffect
4| assert (i == 1);
5| sizeof(vla[i++]); // With sideffect
6| assert (i == 2);
Note: ptype/whatsis still do not allow any sideeffects.
This patch was motivated by:
https://sourceware.org/ml/gdb-patches/2014-01/msg00732.html
* eval.c (evaluate_subexp_for_sizeof): Add enum noside argument.
(evaluate_subexp_standard): Pass noside argument.
(evaluate_subexp_for_sizeof) <BINOP_SUBSCRIPT>: Handle subscript case
if noside equals EVAL_NORMAL. If the subscript yields a vla type
re-evaluate subscript operation with EVAL_NORMAL to enable sideffects.
* gdbtypes.c (resolve_dynamic_bounds): Mark bound as evaluated.
* gdbtypes.h (enum range_flags): Add RANGE_EVALUATED case.
testsuite/gdb.base/
* vla-sideeffect.c: New file.
* vla-sideeffect.exp: New file.
A variable location might be a constant value and therefore no inferior memory
access is needed to read the content. In this case try to resolve the type
bounds.
* findvar.c (default_read_var_value): Resolve dynamic bounds if location
points to a constant blob.
This patch adds support for DW_AT_count as requested in the code review:
https://sourceware.org/ml/gdb-patches/2013-11/msg00200.html
* dwarf2read.c (read_subrange_type): Convert DW_AT_count to a dynamic
property and store it as the high bound and flag the range accordingly.
* gdbtypes.c (resolve_dynamic_bounds): If range is flagged as
RANGE_UPPER_BOUND_IS_COUNT assign low + high - 1 as the new high bound.
* gdbtypes.h (enum range_flags): New enum.
(struct range_bounds): Add flags member.
1| void foo (size_t n) {
2| int vla[n];
3| }
Given the following expression
(gdb) ptype &vla
Gdb evaluates the expression with EVAL_AVOID_SIDE_EFFECTS and thus
does not resolve the bounds information and misinterprets the high
bound as a constant. The current output is:
type = int (*)[1289346]
this patch deals with this case and prints:
type = int (*)[variable length]
instead.
* c-typeprint.c (c_type_print_varspec_suffix): Added
check for not yet resolved high bound. If unresolved, print
"variable length" string to the console instead of random
length.
Constructing a value based on a type and address might change the type
of the newly constructed value. Thus re-fetch type via value_type to ensure
we have the correct type at hand.
* ada-lang.c (ada_value_primitive_packed_val): Re-fetch type from value.
(ada_template_to_fixed_record_type_1): Likewise.
(ada_to_fixed_type_1): Likewise.
* cp-valprint.c (cp_print_value_fields_rtti): Likewise.
(cp_print_value): Likewise.
* d-valprint.c (dynamic_array_type): Likewise.
* eval.c (evaluate_subexp_with_coercion): Likewise.
* findvar.c (address_of_variable): Likewise.
* jv-valprint.c (java_value_print): Likewise.
* valops.c (value_ind): Likewise.
* value.c (coerce_ref): Likewise.
This patch enables the sizeof operator for indirections:
1| void foo (size_t n) {
2| int vla[n];
3| int *vla_ptr = &vla;
4| }
(gdb) p sizeof(*vla_ptr)
yields sizeof (size_t) * n.
* eval.c (evaluate_subexp_for_sizeof) <UNOP_IND>: Create an indirect
value and retrieve the dynamic type size.
In C99 the sizeof operator computes the size of a variable length array
at runtime (6.5.3.4 The sizeof operator). This patch reflects the semantic
change in the debugger.
We now are able to get the size of a vla:
1| void foo (size_t n) {
2| int vla[n];
3| }
(gdb) p sizeof(vla)
yields N * sizeof(int).
* eval.c (evaluate_subexp_for_sizeof) <OP_VAR_VALUE>: If the type
passed to sizeof is dynamic evaluate the argument to compute the length.
The dwarf standard allow certain attributes to be expressed as dwarf
expressions rather than constants. For instance upper-/lowerbound attributes.
In case of a c99 variable length array the upperbound is a dynamic attribute.
With this change c99 vla behave the same as with static arrays.
1| void foo (size_t n) {
2| int ary[n];
3| memset(ary, 0, sizeof(ary));
4| }
(gdb) print ary
$1 = {0 <repeats 42 times>}
* dwarf2loc.c (dwarf2_locexpr_baton_eval): New function.
(dwarf2_evaluate_property): New function.
* dwarf2loc.h (dwarf2_evaluate_property): New function prototype.
* dwarf2read.c (attr_to_dynamic_prop): New function.
(read_subrange_type): Use attr_to_dynamic_prop to read high bound
attribute.
* gdbtypes.c: Include dwarf2loc.h.
(is_dynamic_type): New function.
(resolve_dynamic_type): New function.
(resolve_dynamic_bounds): New function.
(get_type_length): New function.
(check_typedef): Use get_type_length to compute type length.
* gdbtypes.h (TYPE_HIGH_BOUND_KIND): New macro.
(TYPE_LOW_BOUND_KIND): New macro.
(is_dynamic_type): New function prototype.
* value.c (value_from_contents_and_address): Call resolve_dynamic_type
to resolve dynamic properties of the type. Update comment.
* valops.c (get_value_at, value_at, value_at_lazy): Update comment.
The rational behind this patch is to get started to implement the feature
described in dwarf4 standard (2.19) Static and Dynamic Values of Attributes.
It adds new BOUND_PROP to store either a constant, exprloc, or reference to
describe an upper-/lower bound of a subrange. Other than that no new features
are introduced.
* dwarf2read.c (read_subrange_type): Use struct bound_prop for
declaring high/low bounds and change uses accordingly. Call
create_range_type instead of create_static_range_type.
* gdbtypes.c (create_range_type): New function.
(create_range_type): Convert bounds into struct bound_prop and pass
them to create_range_type.
* gdbtypes.h (struct bound_prop): New struct.
(create_range_type): New function prototype.
(struct range_bounds): Use struct bound_prop instead of LONGEST for
high/low bounds. Remove low_undefined/high_undefined and adapt all uses.
(TYPE_LOW_BOUND,TYPE_HIGH_BOUND): Adapt macros to refer to the static
part of the bound.
* parse.c (follow_types): Set high bound kind to BOUND_UNDEFINED.
