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2023-05-15Correctly handle forward DIE references in scannerTom Tromey1-3/+2
The cooked index scanner has special code to handle forward DIE references. However, a bug report lead to the discovery that this code does not work -- the "deferred_entry::spec_offset" field is written to but never used, i.e., the lookup is done using the wrong key. This patch fixes the bug and adds a regression test. The test in the bug itself used a thread_local variable, which provoked a failure at runtime. This test instead uses "maint print objfiles" and then inspects to ensure that the entry in question has a parent. This lets us avoid a clang dependency in the test. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30271
2023-05-12Handle Ada Pragma Import and Pragma ExportTom Tromey3-0/+252
Ada can import C APIs and also export Ada constructs to C via Pragma Import and Pragma Export. This patch adds support for these to gdb, by arranging to either defer some aspects of a symbol to the underlying C symbol (for Import) or by introducing a second symbol (for Export). A somewhat tricky approach is needed, both because gdb doesn't generally handle symbol aliasing, and because Ada treats symbol names in an unusual way (as compared to the rest of gdb).
2023-05-12Add dynamic_prop::is_constantTom Tromey1-5/+5
I noticed many spots checking whether a dynamic property's kind is PROP_CONST. Some spots, I think, are doing a slightly incorrect check -- checking for != PROP_UNDEFINED where == PROP_CONST is actually required, the key thing being that const_val may only be called for PROP_CONST properties. This patch adds dynamic::is_constant and then updates these checks to use it. Regression tested on x86-64 Fedora 36.
2023-05-11Do not print <synthetic pointer> when piece is optimized outTom Tromey1-6/+13
A user reported a bug where printing a certain array of integer types would result in the nonsensical: (gdb) p l_126 $1 = {6639779683436459270, <synthetic pointer>, <synthetic pointer>, <synthetic pointer>} I tracked this down to some issues in the DWARF expression code. First, check_pieced_synthetic_pointer did not account for the situation where a location expression does not describe all the bits of a value -- in this case it returned true, meaning there is a synthetic pointer, but in fact these bits are optimized out. (It turns out this incorrect output had already been erroneously tested for as well.) Next, rw_pieced_value did not mark these bits as optimized-out, either. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30296
2023-05-05Simplify decode_locdescTom Tromey1-137/+66
While looking into another bug, I noticed that the DWARF cooked indexer picks up an address for this symbol: <1><82>: Abbrev Number: 2 (DW_TAG_variable) <83> DW_AT_specification: <0x9f> <87> DW_AT_location : 10 byte block: e 0 0 0 0 0 0 0 0 e0 (DW_OP_const8u: 0 0; DW_OP_GNU_push_tls_address or DW_OP_HP_unknown) <92> DW_AT_linkage_name: (indirect string, offset: 0x156): _ZN9container8tlsvar_0E This happens because decode_locdesc allows the use of DW_OP_GNU_push_tls_address. This didn't make sense to me. I looked into it a bit more, and I think decode_locdesc is used in three ways: 1. Find a constant address of a symbol that happens to be encoded as a location expression. 2. Find the offset of a function in a virtual table. (This one should probably be replaced by code to just evaluate the expression in gnu-v3-abi.c -- but there's no point yet because no compiler actually seems to emit correct DWARF here, see the bug linked in the patch.) 3. Find the offset of a field, if the offset is a constant. None of these require TLS. This patch simplifies decode_locdesc by removing any opcodes that don't fit into the above. It also changes the API a little, to make it less difficult to use. Regression tested on x86-64 Fedora 36.
2023-04-29gdb: Fix building with latest libc++Manoj Gupta1-1/+1
Latest libc++[1] causes transitive include to <locale> when <mutex> or <thread> header is included. This causes gdb to not build[2] since <locale> defines isupper/islower etc. functions that are explicitly macroed-out in safe-ctype.h to prevent their use. Use the suggestion from libc++ to include <locale> internally when building in C++ mode to avoid build errors. Use safe-gdb-ctype.h as the include instead of "safe-ctype.h" to keep this isolated to gdb since rest of binutils does not seem to use much C++. [1]: https://reviews.llvm.org/D144331 [2]: https://issuetracker.google.com/issues/277967395
2023-04-21Handle function descriptors in call_site_targetTom Tromey1-1/+5
call_site_target::iterate_over_addresses may look up a minimal symbol. On platforms like PPC64 that use function descriptors, this may find an unexpected address. The fix is to use gdbarch_convert_from_func_ptr_addr to convert from a function descriptor to the address recorded at the call site. I've added a new test case that is based on the internal AdaCore test that provoked this bug. However, I'm unable to test it as-is on PPC64.
2023-04-18PowerPC: fix _Float128 type output stringCarl Love1-4/+19
PowerPC supports two 128-bit floating point formats, the IBM long double and IEEE 128-bit float. The issue is the DWARF information does not distinguish between the two. There have been proposals of how to extend the DWARF information as discussed in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104194 but has not been fully implemented. GCC introduced the _Float128 internal type as a work around for the issue. The workaround is not transparent to GDB. The internal _Float128 type name is printed rather then the user specified long double type. This patch adds a new gdbarch method to allow PowerPC to detect the GCC workaround. The workaround checks for "_Float128" name when reading the base typedef from the die_info. If the workaround is detected, the type and format fields from the _Float128 typedef are copied to the long double typedef. The same is done for the complex long double typedef. This patch fixes 74 regression test failures in gdb.base/whatis-ptype-typedefs.exp on PowerPC with IEEE float 128 as the default on GCC. It fixes one regression test failure in gdb.base/complex-parts.exp. The patch has been tested on Power 10 where GCC defaults to IEEE Float 128-bit and on Power 10 where GCC defaults to the IBM 128-bit float. The patch as also been tested on X86-64 with no new regression failures.
2023-04-17[gdb/symtab] Handle empty file name in .debug_line sectionTom de Vries1-0/+4
With DWARF 5, it's possible to produce an empty file name in the File Name Table of the .debug_line section: ... The File Name Table (offset 0x112, lines 1, columns 2): Entry Dir Name 0 1 (indirect line string, offset: 0x2d): ... Currently, when gdb reads an exec containing such debug info, it segfaults: ... Thread 1 "gdb" received signal SIGSEGV, Segmentation fault. 0x000000000072cd38 in dwarf2_start_subfile (cu=0x2badc50, fe=..., lh=...) at \ gdb/dwarf2/read.c:18716 18716 if (!IS_ABSOLUTE_PATH (filename) && dirname != NULL) ... because read_direct_string transforms "" into a nullptr, and we end up dereferencing the nullptr. Note that the behaviour of read_direct_string has been present since repo creation. Fix this in read_formatted_entries, by transforming nullptr filenames in to "" filenames. Tested on x86_64-linux. Reviewed-By: Tom Tromey <tom@tromey.com> PR symtab/30357 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30357
2023-04-10gdb/dwarf: Fix MinGW buildThiago Jung Bauermann1-1/+1
Unfortunately MinGW doesn't support std::future yet, so this causes the build to fail. Use GDB's version which provides a fallback for this case. Tested for regressions on native aarch64-linux. Approved-By: Tom Tromey <tromey@adacore.com>
2023-03-31Fix race in background index-cache writingTom Tromey3-11/+24
Tom de Vries pointed out a bug in the index-cache background writer -- sometimes it will fail. He also noted that it fails when the number of worker threads is set to zero. These turn out to be the same problem -- the cache can't be written to until the per-BFD's "index_table" member is set. This patch avoids the race by rearranging the code slightly, to ensure the cache cannot possibly be written before the member is set. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30261
2023-03-31GDB: Bring back the handling of DW_CC_programMaciej W. Rozycki1-1/+27
Fix a functional regression and restore the handling of DW_CC_program code of DW_AT_calling_convention attribute for determining the name of the starting function of the program where the DW_AT_main_subprogram attribute has not been provided, such as with Fortran code compiled with GCC versions 4.5.4 and below, or where DWARF version 3 or below has been requested. Without it "main" is considered the starting function. Cf. GCC PR fortran/43414. Original code was removed with commit 6209cde4ddb8 ("Delete DWARF psymtab code"), and then an update to complement commit 81873cc81eff ("[gdb/symtab] Support DW_AT_main_subprogram with -readnow.") has also been included here.
2023-03-29Use the correct frame when evaluating a dynamic propertyTom Tromey1-2/+2
The test case in this patch shows an unusual situation: an Ada array has a dynamic bound, but the bound comes from a frame that's referred to by the static link. This frame is correctly found when evaluating the array variable itself, but is lost when evaluating the array's bounds. This patch fixes the problem by passing this frame through to value_at_lazy in the DWARF expression evaluator.
2023-03-27Populate seen_names hash in cooked_index_shard::do_finalizeTom Tromey1-0/+1
Hannes pointed out that cooked_index_shard::do_finalize never populates the seen_names hash table. This patch adds the necessary store. This reduces memory use a little for "gdb gdb": (before) Space used: 28909568 (+0 for this command) (after) Space used: 28884992 (+0 for this command) What this means, btw, is that in gdb there are not many symbols that are both mentioned in many CUs and that also require name canonicalization. It's possible this would differ in other programs.
2023-03-24[gdb/symtab] Fix line number of static const class memberTom de Vries1-2/+1
Since commit 6d263fe46e0 ("Avoid bad breakpoints with --gc-sections"), there was a silent regression on openSUSE Leap 15.4 for test-case gdb.cp/m-static.exp, from: ... (gdb) info variable everywhere^M All variables matching regular expression "everywhere":^M ^M File /home/vries/tmp.local-remote-host-native/m-static.h:^M 8: const int gnu_obj_4::everywhere;^M (gdb) ... to: ... (gdb) info variable everywhere^M All variables matching regular expression "everywhere":^M ^M File /data/vries/gdb/src/gdb/testsuite/gdb.cp/m-static.h:^M 8: const int gnu_obj_4::everywhere;^M ^M File /data/vries/gdb/src/gdb/testsuite/gdb.cp/m-static1.cc:^M 8: const int gnu_obj_4::everywhere;^M (gdb) ... Another regression was found due to that commit, and it was fixed in commit 99d679e7b30 ("[gdb/symtab] Fix "file index out of range" complaint") by limiting the scope of the fix in the original commit. Fix this regression by yet further limiting the scope of that fix, making sure that this bit in dwarf_decode_lines is executed again for m-static1.cc: ... /* Make sure a symtab is created for every file, even files which contain only variables (i.e. no code with associated line numbers). */ ... Tested on x86_64-linux. PR symtab/30265 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30265
2023-03-22Remove unnecessary castTom Tromey1-2/+1
I found an upcast from template_symbol to symbol. This was necessary long ago, but since symbols use inheritance now, it is not. This patch removes it. Tested by rebuilding.
2023-03-18Rename objfile_type to builtin_typeTom Tromey2-9/+9
This renames objfile_type to be an overload of builtin_type, in preparation for their unification. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Use type allocator for set typesTom Tromey1-1/+2
This changes the set type creation function to accept a type allocator, and updates all the callers. Note that symbol readers should generally allocate on the relevant objfile, regardless of the underlying type of the set, which is what this patch implements. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Use type allocator for array typesTom Tromey1-4/+5
This changes the array type creation functions to accept a type allocator, and updates all the callers. Note that symbol readers should generally allocate on the relevant objfile, regardless of the placement of the index type of the array, which is what this patch implements. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Use type allocator for range typesTom Tromey1-7/+11
This changes the range type creation functions to accept a type allocator, and updates all the callers. Note that symbol readers should generally allocate on the relevant objfile, regardless of the underlying type of the range, which is what this patch implements. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Unify arch_pointer_type and init_pointer_typeTom Tromey1-1/+1
This unifies arch_pointer_type and init_pointer_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Unify arch_decfloat_type and init_decfloat_typeTom Tromey1-1/+1
This unifies arch_decfloat_type and init_decfloat_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Unify arch_float_type and init_float_typeTom Tromey1-1/+1
This unifies arch_float_type and init_float_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Unify arch_boolean_type and init_boolean_typeTom Tromey1-1/+1
This unifies arch_boolean_type and init_boolean_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Unify arch_character_type and init_character_typeTom Tromey1-4/+4
This unifies arch_character_type and init_character_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Unify arch_integer_type and init_integer_typeTom Tromey2-4/+10
This unifies arch_integer_type and init_integer_type by using a type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Remove init_typeTom Tromey1-13/+18
This removes init_type, replacing all uses with the new type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-18Remove alloc_typeTom Tromey1-7/+8
This removes alloc_type, replacing all uses with the new type allocator. Reviewed-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-17Fix line table regressionTom Tromey1-1/+2
Simon pointed out a line table regression, and after a couple of false starts, I was able to reproduce it by hand using his instructions. The bug is that most of the code in do_mixed_source_and_assembly uses unrelocated addresses, but one spot does: pc = low; ... after the text offset has been removed. This patch fixes the problem by introducing a new type to represent unrelocated addresses in the line table. This prevents this sort of bug to some degree (it's still possible to manipulate a CORE_ADDR in a bad way, this is unavoidable). However, this did let the compiler flag a few spots in that function, and now it's not possible to compare an unrelocated address from a line table with an ordinary CORE_ADDR. Regression tested on x86-64 Fedora 36, though note this setup never reproduced the bug in the first place. I also tested it by hand on the disasm-optim test program.
2023-03-14Add methods and operators to gdb_mpzTom Tromey1-26/+20
This adds various methods and operators to gdb_mpz, as a step toward hiding the implementation. This only adds the operators that were needed. Many more could be added as required.
2023-03-11Change linetables to be objfile-independentTom Tromey1-3/+2
This changes linetables to not add the text offset to the addresses they contain. I did this in a few steps, necessarily combined together in one patch: I renamed the 'pc' member to 'm_pc', added the appropriate accessors, and then recompiled. Then I fixed all the errors. Where possible I generally chose to use the raw_pc accessor, as it is less expensive. Note that this patch discounts the possibility that the text section offset might cause wraparound in the addresses in the line table. However, this was already discounted -- in particular, objfile_relocate1 did not re-sort the table in this scenario. (There was a bug open about this, but as far as I can tell this has never happened, it's not even clear what inspired that bug.) Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-09gdb, gdbserver, gdbsupport: fix whitespace issuesSimon Marchi2-15/+15
Replace spaces with tabs in a bunch of places. Change-Id: If0f87180f1d13028dc178e5a8af7882a067868b0
2023-03-07Clean up attribute reprocessingTom Tromey1-104/+101
I ran across the attribute reprocessing code recently and noticed that it unconditionally sets members of the CU when reading a DIE. Also, each spot reading attributes needs to be careful to "reprocess" them as a separate step. This seemed excessive to me, because while reprocessing applies to any DIE, setting the CU members is only necessary for the toplevel DIE in any given CU. This patch introduces a new read_toplevel_die function and changes a few spots to call it. This is easily done because reading the toplevel DIE is already special. I left the reprocessing flag and associated checks in attribute. It could be stripped out, but I am not sure it would provide much value (maybe some iota of performance). Regression tested on x86-64 Fedora 36.
2023-03-07Fix selfcheck regression due to new maint commandTom Tromey1-2/+2
Simon points out that the new maint command, intended to fix a regression, also introduces a new regression in "maint selftest". This patch fixes the error. I did a full regression test on x86-64 Fedora 36.
2023-03-07Ensure index cache entry written in testTom Tromey1-0/+15
Now that index cache files are written in the background, one test in index-cache.exp is racy -- it assumes that the cache file will have been written during startup. This patch fixes the problem by introducing a new maintenance command to wait for all pending writes to the index cache. Approved-By: Simon Marchi <simon.marchi@efficios.com> Reviewed-By: Eli Zaretskii <eliz@gnu.org>
2023-03-01gdb: update some copyright years (2022 -> 2023)Simon Marchi2-2/+2
The copyright years in the ROCm files (e.g. solib-rocm.c) are wrong, they end in 2022 instead of 2023. I suppose because I posted (or at least prepared) the patches in 2022 but merged them in 2023, and forgot to update the year. I found a bunch of other files that are in the same situation. Fix them all up. Change-Id: Ia55f5b563606c2ba6a89046f22bc0bf1c0ff2e10 Reviewed-By: Tom Tromey <tom@tromey.com>
2023-03-01Use const for dwarf2_property_batonTom Tromey2-5/+5
Once a baton is stored in a struct type, it doesn't make sense to modify it. This patch constifies the API. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-03-01Make gdb property batons type-safeTom Tromey1-8/+4
gdbtypes treats dynamic property batons as 'void *', but in actuality the only users all use dwarf2_property_baton. This patch changes this code to be type-safe. If a new type is needed here, it seems like that too could be done in a type-safe way. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-02-27gdb: don't treat empty enums as flag enumsAndrew Burgess1-0/+2
In C++ it is possible to use an empty enum as a strong typedef. For example, a user could write: enum class my_type : unsigned char {}; Now my_type can be used like 'unsigned char' except the compiler will not allow implicit conversion too and from the native 'unsigned char' type. This is used in the standard library for things like std::byte. Currently, when GDB prints a value of type my_type, it looks like this: (gdb) print my_var $1 = (unknown: 0x4) Which isn't great. This gets worse when we consider something like: std::vector<my_type> vec; When using a pretty-printer, this could look like this: std::vector of length 2, capacity 2 = {(unknown: 0x2), (unknown: 0x4)} Clearly not great. This is described in PR gdb/30148. The problem here is in dwarf2/read.c, we assume all enums are flag enums unless we find an enumerator with a non-flag like value. Clearly an empty enum contains no non-flag values, so we assume the enum is a flag enum. I propose adding an extra check here; that is, an empty enum should never be a flag enum. With this the above cases look more like: (gdb) print my_var $1 = 4 and: std::vector of length 2, capacity 2 = {2, 4} Which look much better. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30148 Reviewed-By: Tom Tromey <tom@tromey.com>
2023-02-24Write the DWARF index in the backgroundTom Tromey4-19/+101
The new DWARF cooked indexer interacts poorly with the DWARF index cache. In particular, the cache will require gdb to wait for the cooked index to be finalized. As this happens in the foreground, it means that users with this setting enabled will see a slowdown. This patch changes gdb to write the cache entry a worker thread. (As usual, in the absence of threads, this work is simply done immediately in the main thread.) Some care is taken to ensure that this can't crash, and that gdb will not exit before the task is complete. To avoid use-after-free problems, the DWARF per-BFD object explicitly waits for the index cache task to complete. To avoid gdb exiting early, an exit observer is used to wait for all such pending tasks. In normal use, neither of these waits will be very visible. For users using "-batch" to pre-generate the index, though, it would be. However I don't think there is much to be done about this, as it was the status quo ante.
2023-02-24Only use the per-BFD object to write a DWARF indexTom Tromey5-60/+48
The DWARF index does not need access to the objfile or per-objfile objects when writing -- it's entirely based on the objfile-independent per-BFD data. This patch implements this idea by changing the entire API to only be passed the per-BFD object. This simplifies some lifetime reasoning for the next patch. This patch removes some code that ensures that the BFD came from a file. It seems to me that checking for the existence of a build-id is good enough for the index cache.
2023-02-20[gdb/symtab] Trust epilogue unwind info for unknown or non-gcc producerTom de Vries1-1/+7
Currently we only trust epilogue unwind info only for gcc >= 4.5.0. This has the effect that we don't trust epilogue unwind info for: - unknown producers (CU without DW_AT_producer attribute) - non-gcc producers (say, clang). Instead, only distrust epilogue unwind info only for gcc < 4.5.0.
2023-02-19Convert block_linkage_function to methodTom Tromey2-4/+4
This converts block_linkage_function to be a method. This was mostly written by script.
2023-02-19Convert more block functions to methodsTom Tromey1-2/+2
This converts block_scope, block_set_scope, block_using, and block_set_using to be methods. These are all done at once to make it easier to also convert block_initialize_namespace at the same time. This was mostly written by script.
2023-02-18Fix "start" for D, Rust, etcTom Tromey3-24/+62
The new DWARF indexer broke "start" for some languages. For D, it is broken because, while the code in cooked_index_shard::add specifically excludes Ada, it fails to exclude D. This means that the C "main" will be detected as "main" here -- whereas what is intended is for the code in find_main_name to use d_main_name to find the name. The Rust compiler, on the other hand, uses DW_AT_main_subprogram. However, the code in dwarf2_build_psymtabs_hard fails to create a fully-qualified name, so the name always ends up as plain "main". For D and Ada, a very simple approach suffices: remove the check against "main" from cooked_index_shard::add. This also has the benefit of slightly speeding up DWARF indexing. I assume this approach will work for Pascal and Modula-2 as well, but I don't have a way to test those at present. For Rust, though, this is not sufficient. And, computing the fully-qualified name in dwarf2_build_psymtabs_hard will crash, because cooked_index_entry::full_name uses the canonical name -- and that is not computed until after canonicalization. However, we don't want to wait for canonicalization to be done before computing the main name. That would remove any benefit from doing canonicalization is the background. This patch solves this dilemma by noticing that languages using DW_AT_main_subprogram are, currently, disjoint from languages requiring canonicalization. Because of this, we can add a parameter to full_name to let us avoid crashes, slowdowns, and races here. This is kind of tricky and ugly, so I've tried to comment it sufficiently. While doing this, I had to change gdb.dwarf2/main-subprogram.exp. A different possibility here would be to ignore the canonicalization needs of C in this situation, because those only affect certain types. However, I chose this approach because the test case is artificial anyhow. A long time ago, in an earlier threading attempt, I changed the global current_language to be a function (hidden behind a macro) to let us attempt lazily computing the current language. Perhaps this approach could still be made to work. However, that also seemed rather tricky, more so than this patch. Reviewed-By: Andrew Burgess <aburgess@redhat.com> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30116
2023-02-17Avoid manual memory management in go-lang.cTom Tromey1-1/+1
I noticed a couple of spots in go-lang.c that could be improved by using unique_ptr. Reviewed-By: Andrew Burgess <aburgess@redhat.com>
2023-02-15Have value::bits_synthetic_pointer return boolTom Tromey1-3/+3
This changes value::bits_synthetic_pointer to return bool and fixes up some fallout from this. Reviewed-By: Bruno Larsen <blarsen@redhat.com>
2023-02-15Change value::m_stack to boolTom Tromey1-1/+1
This changes value::m_stack to be a bool and updates the various uses. Reviewed-By: Bruno Larsen <blarsen@redhat.com>
2023-02-15Change value::m_initialized to boolTom Tromey2-5/+5
This changes value::m_initialized to be a bool and updates the various uses. Reviewed-By: Bruno Larsen <blarsen@redhat.com>
2023-02-15Change value::m_lazy to boolTom Tromey1-1/+1
This changes value::m_lazy to be a bool and updates the various uses. Reviewed-By: Bruno Larsen <blarsen@redhat.com>