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16 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
| 213516ef31 |
Update copyright year range in header of all files managed by GDB
This commit is the result of running the gdb/copyright.py script, which automated the update of the copyright year range for all source files managed by the GDB project to be updated to include year 2023. |
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| 4749b84b51 |
gdb/riscv: better support for fflags and frm registers
First, some background on the RISC-V registers fflags, frm, and fcsr. These three registers all relate to the floating-point status and control mechanism on RISC-V. The fcsr is the floatint-point control status register, and consists of two parts, the flags (bits 0 to 4) and the rounding-mode (bits 5 to 7). The fcsr register is just one of many control/status registers (or CSRs) available on RISC-V. The fflags and frm registers are also CSRs. These CSRs are aliases for the relevant parts of the fcsr register. So fflags is an alias for bits 0 to 4 of fcsr, and frm is an alias for bits 5 to 7 of fcsr. This means that a user can change the floating-point rounding mode either, by writing a complete new value into fcsr, or by writing just the rounding mode into frm. How this impacts on GDB is like this: a target description could, legitimately include all three registers, fcsr, fflags, and frm. The QEMU target currently does this, and this makes sense. The target is emulating the complete system, and has all three CSRs available, so why not tell GDB about this. In contrast, the RISC-V native Linux target only has access to the fcsr. This is because the ptrace data structure that the kernel uses for reading and writing floating point state only contains a copy of the fcsr, after all, this one field really contains both the fflags and frm fields, so why carry around duplicate data. So, we might expect that the target description for the RISC-V native Linux GDB would only contain the fcsr register. Unfortunately, this is not the case. The RISC-V native Linux target uses GDB's builtin target descriptions by calling riscv_lookup_target_description, this will then add an fpu feature from gdb/features/riscv, either 32bit-fpu.xml or 64bit-fpu.xml. The problem, is that these features include an entry for fcsr, fflags, and frm. This means that GDB expects the target to handle reading and writing these registers. And the RISC-V native Linux target currently doesn't. In riscv_linux_nat_target::store_registers and riscv_linux_nat_target::fetch_registers only the fcsr register is handled, this means that, for RISC-V native Linux, the fflags and frm registers always show up as <unavailable> - they are present in the target description, but the target doesn't know how to access the registers. A final complication relating to these floating pointer CSRs is which target description feature the registers appear in. These registers are CSRs, so it would seem sensible that these registers should appear in the CSR target description feature. However, when I first added RISC-V target description support, I was using a RISC-V simulator that didn't support any CSRs other than the floating point related ones. This simulator bundled all the float related CSRs into the fpu target feature. This didn't feel completely unreasonable to me, and so I had GDB check for these registers in either target feature. In this commit I make some changes relating to how GDB handles the three floating point CSR: 1. Remove fflags and frm from 32bit-fpu.xml and 64bit-fpu.xml. This means that the default RISC-V target description (which RISC-V native FreeBSD), and the target descriptions created for RISC-V native Linux, will not include these registers. There's nothing stopping some other target (e.g. QEMU) from continuing to include all three of these CSRs, the code in riscv-tdep.c continues to check for all three of these registers, and will handle them correctly if they are present. 2. If a target supplied fcsr, but does not supply fflags and/or frm, then RISC-V GDB will now create two pseudo registers in order to emulate the two missing CSRs. These new pseudo-registers do the obvious thing of just reading and writing the fcsr register. 3. With the new pseudo-registers we can no longer make use of the GDB register numbers RISCV_CSR_FFLAGS_REGNUM and RISCV_CSR_FRM_REGNUM. These will be the numbers used if the target supplies the registers in its target description, but, if GDB falls back to using pseudo-registers, then new, unique numbers will be used. To handle this I've added riscv_gdbarch_tdep::fflags_regnum and riscv_gdbarch_tdep::frm_regnum, I've then updated the RISC-V code to compare against these fields. When adding the pseudo-register support, it is important that the pseudo-register numbers are calculated after the call to tdesc_use_registers. This is because we don't know the total number of physical registers until after this call, and the psuedo-register numbers must follow on from the real (target supplied) registers. I've updated some tests to include more testing of the fflags and frm registers, as well as adding a new test. |
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| 4a94e36819 |
Automatic Copyright Year update after running gdb/copyright.py
This commit brings all the changes made by running gdb/copyright.py as per GDB's Start of New Year Procedure. For the avoidance of doubt, all changes in this commits were performed by the script. |
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| 96f842cbdb |
gdb/riscv: add support for vector registers in target descriptions
This commit adds support to RISC-V GDB for vector registers in the incoming target description. The vector registers should be described in a feature called "org.gnu.gdb.riscv.vector", and should contain the register v0 to v31. There's no restriction on the size or type of these registers, so the target description can set these up as it requires. However, if the target feature is present then all of the registers must be present, and they must all be the same size, these requirements are, I believe, inline with the RISC-V vector extension. The DWARF register numbers for the vector registers have been added, and the code to map between GDB's internal numbering and the DWARF numbering has been updated. I have not yet added a feature/riscv/*.xml file for the vector extension, the consequence of this is that we can't, right now, detect vector registers on a native target, this patch is all about supporting vectors on a remote target. It is worth noting that I don't actually have access to a RISC-V target with vectors, so the only testing that this patch has had has been done using 'set tdesc filename ....' to load a target description to which I have manually added the vector feature. This has shown that the vector register feature can be successfully parsed, and that the registers show up in the expected register groups. Additionally, the RISC-V vector extension is currently at v0.10, which is also the v1.0 draft release. However, this extension is not yet finalised. It is possible (but unlikely I think) that the register set could change between now and the final release of the vector extension. If this were to happen then we would potentially end up changing the requirements for the new org.gnu.gdb.riscv.vector feature. I really don't think it is likely that the register set will change this late in the process, and even if it did, changing the feature requirements will not be a problem as far as I am concerned (when the alternative is GDB just continues without this feature for now). gdb/ChangeLog: * NEWS: Mention new target feature name. * arch/riscv.c (riscv_create_target_description): GDB doesn't currently create target descriptions containing vector registers. * arch/riscv.h (struct riscv_gdbarch_features) <vlen>: New member variable. <operator==>: Also compare vlen. <hash>: Also include vlen. * riscv-tdep.c (riscv_feature_name_vector): New static global. (struct riscv_vector_feature): New struct. (riscv_vector_feature): New static global. (riscv_register_reggroup_p): Ensure vector registers are part of the 'all' group, and part of the 'vector' group. (riscv_dwarf_reg_to_regnum): Handle vector registers. (riscv_gdbarch_init): Check vector register feature. * riscv-tdep.h: Add vector registers to GDB's internal register numbers, and to the DWARF register numbers. gdb/doc/ChangeLog: * gdb.texinfo (RISC-V Features): Mention vector register feature. |
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| 3666a04883 |
Update copyright year range in all GDB files
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
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| 2542804022 |
gdb/riscv: rewrite target description validation, add rv32e support
This commit started as adding rv32e support to gdb. The rv32e architecture is a cut-down rv32i, it only has 16 x-registers compared to the usual 32, and an rv32e target should not have any floating point registers. In order to add this I needed to adjust the target description validation checks that are performed from riscv_gdbarch_init, and I finally got fed up with the current scheme of doing these checks and rewrote this code. Unfortunately the rv32e changes are currently mixed in with the rewrite of the validation scheme. I could split these apart if anyone is really interested in seeing these two ideas as separate patches. The main idea behind this change is that where previously I tried to have a purely data driven approach, a set of tables one for each expected feature, and then a single generic function that would validate a feature given a table, I have created a new class for each feature. Each class has its own check member function which allows the logic for how to check each feature to be different. I think the new scheme is much easier to follow. There are some other changes that I made to the validation code as part of this commit. I've relaxed some of the checks related to the floating point CSRs. Previously the 3 CSRs fflags, frm, and fcsr all had to be present in either the fpu feature or the csr feature. This requirement is now relaxed, if the CSRs are not present then gdb will not reject the target description. My thinking here is that there's no gdb functionality that specifically requires these registers, and so, if a target offers a description without these registers nothing else in gdb should stop working. And as part of the rv32e support targets now only have to provide the first 16 x-registers and $pc. The second half of the x-registers (x16 -> x31) are now optional. gdb/ChangeLog: * arch/riscv.c: Include 'rv32e-xregs.c'. (riscv_create_target_description): Update to handle rv32e. * arch/riscv.h (struct riscv_gdbarch_features) <embedded>: New member variable. <operator==>: Update to account for new field. <hash>: Likewise. * features/Makefile (FEATURE_XMLFILES): Add riscv/rv32e-xregs.xml. * features/riscv/rv32e-xregs.c: Generated. * features/riscv/rv32e-xregs.xml: New file. * riscv-tdep.c (riscv_debug_breakpoints): Move from later in the file. (riscv_debug_infcall): Likewise. (riscv_debug_unwinder): Likewise. (riscv_debug_gdbarch): Likewise. (enum riscv_register_required_status): Delete. (struct riscv_register_feature): Add constructor, delete default constructor, copy, and assign constructors. (struct riscv_register_feature::register_info) <required>: Delete. <check>: Update comment and arguments. (struct riscv_register_feature) <name>: Change to member function. <prefer_first_name>: Delete. <tdesc_feature>: New member function. <registers>: Rename to... <m_registers>: ...this. <m_feature_name>: New member variable. (riscv_register_feature::register_info::check): Update arguments. (riscv_xreg_feature): Rewrite as class, create a single static instance of the class. (riscv_freg_feature): Likewise. (riscv_virtual_feature): Likewise. (riscv_csr_feature): Likewise. (riscv_create_csr_aliases): Has become a member function inside riscv_csr_feature class. (riscv_abi_embedded): New function definition. (riscv_register_name): Adjust to use new feature objects. (struct riscv_call_info) <riscv_call_info>: Check for rv32e abi, and adjust available argument registers. (riscv_features_from_gdbarch_info): Check for EF_RISCV_RVE flag. (riscv_check_tdesc_feature): Delete. (riscv_tdesc_unknown_reg): Adjust to use new feature objects. (riscv_gdbarch_init): Delete target description checking code, and instead call to the new feature objects to perform the checks. Reorder handling of no abi information case, allows small code simplification. (_initialize_riscv_tdep): Remove call, this is now done in the riscv_csr_feature constructor. * riscv-tdep.h (riscv_abi_embedded): Declare. |
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| bbb826f5e9 |
gdb: Delay releasing target_desc_up in more cases
After commit:
commit 51a948fdf0e14fb69ab9e0c79ae8b2415801f9a3
Date: Mon Jul 20 14:18:04 2020 +0100
gdb: Have allocate_target_description return a unique_ptr
There were a few places where we could (should?) have delayed
releasing the target_desc_up until a little later. This commit
catches these cases.
In the case of ARC, the target_desc_up is now exposed right out to
gdbserver, which means making a small change there too.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* arch/aarch32.c (aarch32_create_target_description): Release the
target_desc_up as late as possible.
* arch/aarch64.c (aarch64_create_target_description): Likewise.
* arch/amd64.c (amd64_create_target_description): Likewise.
* arch/arc.c (arc_create_target_description): Return a
target_desc_up, don't release it.
* arch/arc.h (arc_create_target_description): Update declaration.
(arc_lookup_target_description): Move target_desc_up into the
cache, and return a borrowed pointer.
* arch/arm.c (arm_create_target_description): Release the
target_desc_up as late as possible.
* arch/i386.c (i386_create_target_description): Likewise.
* arch/riscv.h (riscv_create_target_description): Update
declaration to match definition.
* arch/tic6x.c (tic6x_create_target_description): Release the
target_desc_up as late as possible.
gdbserver/ChangeLog:
* linux-arc-low.cc (arc_linux_read_description): Release the
unique_ptr returned from arc_create_target_description.
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| d1c9b20ff9 |
gdb/riscv: Update API for looking up target descriptions
In preparation for adding the RISC-V gdbserver, this commit restructures the API for looking up target descriptions. The current API is riscv_create_target_description, which creates a target description from a riscv_gdbarch_features, but also caches the created target descriptions so that for a given features object we always get back the same target description object. This is important for GDB due to the way gdbarch objects are reused. As the same target description is always returned to GDB, and can be returned multiple times, it is returned as a const, however, the current cache actually stores a non-const target description. This is improved in this patch so that the cache holds a const target description. For gdbsever, this caching of the target descriptions is not needed, the gdbserver looks up one target description to describe the target it is actually running on and that is it. Further the gdbserver actually needs to modify the target description that is looked up, so for the gdbsever, returning a const target description is not acceptable. This commit aims to address this by creating two parallel target description APIs, on is the old riscv_create_target_description, however, this no longer performs any caching, and just creates a new target description, and returns it as non-const. The second API is riscv_lookup_target_description, this one performs the caching, and calls riscv_create_target_description to create a target description when needed. In order to make sure the correct API is used in the correct place I have guarded the code using the GDBSERVER define. For GDB the riscv_create_target_description is static, and not generally usable throughout GDB, only the lookup API is global. In gdbserver, the lookup functions, and the cache are not defined or created at all, only the riscv_create_target_description API is available. There should be no user visible changes after this commit. gdb/ChangeLog: * arch/riscv.c (struct riscv_gdbarch_features_hasher): Only define if GDBSERVER is not defined. (riscv_tdesc_cache): Likewise, also store const target_desc. (STATIC_IN_GDB): Define. (riscv_create_target_description): Update declaration with STATIC_IN_GDB. (riscv_lookup_target_description): New function, only define if GDBSERVER is not defined. * arch/riscv.h (riscv_create_target_description): Declare only when GDBSERVER is defined. (riscv_lookup_target_description): New declaration when GDBSERVER is not defined. * nat/riscv-linux-tdesc.c (riscv_linux_read_description): Rename to... (riscv_linux_read_features): ...this, and return riscv_gdbarch_features instead of target_desc. * nat/riscv-linux-tdesc.h: Include 'arch/riscv.h'. (riscv_linux_read_description): Rename to... (riscv_linux_read_features): ...this. * riscv-linux-nat.c (riscv_linux_nat_target::read_description): Update to use riscv_gdbarch_features and riscv_lookup_target_description. * riscv-tdep.c (riscv_find_default_target_description): Use riscv_lookup_target_description instead of riscv_create_target_description. |
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| b811d2c292 |
Update copyright year range in all GDB files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
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| 268a13a5a3 |
Rename common to gdbsupport
This is the next patch in the ongoing series to move gdbsever to the top level. This patch just renames the "common" directory. The idea is to do this move in two parts: first rename the directory (this patch), then move the directory to the top. This approach makes the patches a bit more tractable. I chose the name "gdbsupport" for the directory. However, as this patch was largely written by sed, we could pick a new name without too much difficulty. Tested by the buildbot. gdb/ChangeLog 2019-07-09 Tom Tromey <tom@tromey.com> * contrib/ari/gdb_ari.sh: Change common to gdbsupport. * configure: Rebuild. * configure.ac: Change common to gdbsupport. * gdbsupport: Rename from common. * acinclude.m4: Change common to gdbsupport. * Makefile.in (CONFIG_SRC_SUBDIR, COMMON_SFILES) (HFILES_NO_SRCDIR, stamp-version, ALLDEPFILES): Change common to gdbsupport. * aarch64-tdep.c, ada-lang.c, ada-lang.h, agent.c, alloc.c, amd64-darwin-tdep.c, amd64-dicos-tdep.c, amd64-fbsd-nat.c, amd64-fbsd-tdep.c, amd64-linux-nat.c, amd64-linux-tdep.c, amd64-nbsd-tdep.c, amd64-obsd-tdep.c, amd64-sol2-tdep.c, amd64-tdep.c, amd64-windows-tdep.c, arch-utils.c, arch/aarch64-insn.c, arch/aarch64.c, arch/aarch64.h, arch/amd64.c, arch/amd64.h, arch/arm-get-next-pcs.c, arch/arm-linux.c, arch/arm.c, arch/i386.c, arch/i386.h, arch/ppc-linux-common.c, arch/riscv.c, arch/riscv.h, arch/tic6x.c, arm-tdep.c, auto-load.c, auxv.c, ax-gdb.c, ax-general.c, ax.h, breakpoint.c, breakpoint.h, btrace.c, btrace.h, build-id.c, build-id.h, c-lang.h, charset.c, charset.h, cli/cli-cmds.c, cli/cli-cmds.h, cli/cli-decode.c, cli/cli-dump.c, cli/cli-option.h, cli/cli-script.c, coff-pe-read.c, command.h, compile/compile-c-support.c, compile/compile-c.h, compile/compile-cplus-symbols.c, compile/compile-cplus-types.c, compile/compile-cplus.h, compile/compile-loc2c.c, compile/compile.c, completer.c, completer.h, contrib/ari/gdb_ari.sh, corefile.c, corelow.c, cp-support.c, cp-support.h, cp-valprint.c, csky-tdep.c, ctf.c, darwin-nat.c, debug.c, defs.h, disasm-selftests.c, disasm.c, disasm.h, dtrace-probe.c, dwarf-index-cache.c, dwarf-index-cache.h, dwarf-index-write.c, dwarf2-frame.c, dwarf2expr.c, dwarf2loc.c, dwarf2read.c, event-loop.c, event-top.c, exceptions.c, exec.c, extension.h, fbsd-nat.c, features/aarch64-core.c, features/aarch64-fpu.c, features/aarch64-pauth.c, features/aarch64-sve.c, features/i386/32bit-avx.c, features/i386/32bit-avx512.c, features/i386/32bit-core.c, features/i386/32bit-linux.c, features/i386/32bit-mpx.c, features/i386/32bit-pkeys.c, features/i386/32bit-segments.c, features/i386/32bit-sse.c, features/i386/64bit-avx.c, features/i386/64bit-avx512.c, features/i386/64bit-core.c, features/i386/64bit-linux.c, features/i386/64bit-mpx.c, features/i386/64bit-pkeys.c, features/i386/64bit-segments.c, features/i386/64bit-sse.c, features/i386/x32-core.c, features/riscv/32bit-cpu.c, features/riscv/32bit-csr.c, features/riscv/32bit-fpu.c, features/riscv/64bit-cpu.c, features/riscv/64bit-csr.c, features/riscv/64bit-fpu.c, features/tic6x-c6xp.c, features/tic6x-core.c, features/tic6x-gp.c, filename-seen-cache.h, findcmd.c, findvar.c, fork-child.c, gcore.c, gdb_bfd.c, gdb_bfd.h, gdb_proc_service.h, gdb_regex.c, gdb_select.h, gdb_usleep.c, gdbarch-selftests.c, gdbthread.h, gdbtypes.h, gnu-nat.c, go32-nat.c, guile/guile.c, guile/scm-ports.c, guile/scm-safe-call.c, guile/scm-type.c, i386-fbsd-nat.c, i386-fbsd-tdep.c, i386-go32-tdep.c, i386-linux-nat.c, i386-linux-tdep.c, i386-tdep.c, i387-tdep.c, ia64-libunwind-tdep.c, ia64-linux-nat.c, inf-child.c, inf-ptrace.c, infcall.c, infcall.h, infcmd.c, inferior-iter.h, inferior.c, inferior.h, inflow.c, inflow.h, infrun.c, infrun.h, inline-frame.c, language.h, linespec.c, linux-fork.c, linux-nat.c, linux-tdep.c, linux-thread-db.c, location.c, machoread.c, macrotab.h, main.c, maint.c, maint.h, memattr.c, memrange.h, mi/mi-cmd-break.h, mi/mi-cmd-env.c, mi/mi-cmd-stack.c, mi/mi-cmd-var.c, mi/mi-interp.c, mi/mi-main.c, mi/mi-parse.h, minsyms.c, mips-linux-tdep.c, namespace.h, nat/aarch64-linux-hw-point.c, nat/aarch64-linux-hw-point.h, nat/aarch64-linux.c, nat/aarch64-sve-linux-ptrace.c, nat/amd64-linux-siginfo.c, nat/fork-inferior.c, nat/linux-btrace.c, nat/linux-btrace.h, nat/linux-namespaces.c, nat/linux-nat.h, nat/linux-osdata.c, nat/linux-personality.c, nat/linux-procfs.c, nat/linux-ptrace.c, nat/linux-ptrace.h, nat/linux-waitpid.c, nat/mips-linux-watch.c, nat/mips-linux-watch.h, nat/ppc-linux.c, nat/x86-dregs.c, nat/x86-dregs.h, nat/x86-linux-dregs.c, nat/x86-linux.c, nto-procfs.c, nto-tdep.c, objfile-flags.h, objfiles.c, objfiles.h, obsd-nat.c, observable.h, osdata.c, p-valprint.c, parse.c, parser-defs.h, ppc-linux-nat.c, printcmd.c, probe.c, proc-api.c, procfs.c, producer.c, progspace.h, psymtab.h, python/py-framefilter.c, python/py-inferior.c, python/py-ref.h, python/py-type.c, python/python.c, record-btrace.c, record-full.c, record.c, record.h, regcache-dump.c, regcache.c, regcache.h, remote-fileio.c, remote-fileio.h, remote-sim.c, remote.c, riscv-tdep.c, rs6000-aix-tdep.c, rust-exp.y, s12z-tdep.c, selftest-arch.c, ser-base.c, ser-event.c, ser-pipe.c, ser-tcp.c, ser-unix.c, skip.c, solib-aix.c, solib-target.c, solib.c, source-cache.c, source.c, source.h, sparc-nat.c, spu-linux-nat.c, stack.c, stap-probe.c, symfile-add-flags.h, symfile.c, symfile.h, symtab.c, symtab.h, target-descriptions.c, target-descriptions.h, target-memory.c, target.c, target.h, target/waitstatus.c, target/waitstatus.h, thread-iter.h, thread.c, tilegx-tdep.c, top.c, top.h, tracefile-tfile.c, tracefile.c, tracepoint.c, tracepoint.h, tui/tui-io.c, ui-file.c, ui-out.h, unittests/array-view-selftests.c, unittests/child-path-selftests.c, unittests/cli-utils-selftests.c, unittests/common-utils-selftests.c, unittests/copy_bitwise-selftests.c, unittests/environ-selftests.c, unittests/format_pieces-selftests.c, unittests/function-view-selftests.c, unittests/lookup_name_info-selftests.c, unittests/memory-map-selftests.c, unittests/memrange-selftests.c, unittests/mkdir-recursive-selftests.c, unittests/observable-selftests.c, unittests/offset-type-selftests.c, unittests/optional-selftests.c, unittests/parse-connection-spec-selftests.c, unittests/ptid-selftests.c, unittests/rsp-low-selftests.c, unittests/scoped_fd-selftests.c, unittests/scoped_mmap-selftests.c, unittests/scoped_restore-selftests.c, unittests/string_view-selftests.c, unittests/style-selftests.c, unittests/tracepoint-selftests.c, unittests/unpack-selftests.c, unittests/utils-selftests.c, unittests/xml-utils-selftests.c, utils.c, utils.h, valarith.c, valops.c, valprint.c, value.c, value.h, varobj.c, varobj.h, windows-nat.c, x86-linux-nat.c, xml-support.c, xml-support.h, xml-tdesc.h, xstormy16-tdep.c, xtensa-linux-nat.c, dwarf2read.h: Change common to gdbsupport. gdb/gdbserver/ChangeLog 2019-07-09 Tom Tromey <tom@tromey.com> * configure: Rebuild. * configure.ac: Change common to gdbsupport. * acinclude.m4: Change common to gdbsupport. * Makefile.in (SFILES, OBS, GDBREPLAY_OBS, IPA_OBJS) (version-generated.c, gdbsupport/%-ipa.o, gdbsupport/%.o): Change common to gdbsupport. * ax.c, event-loop.c, fork-child.c, gdb_proc_service.h, gdbreplay.c, gdbthread.h, hostio-errno.c, hostio.c, i387-fp.c, inferiors.c, inferiors.h, linux-aarch64-tdesc-selftest.c, linux-amd64-ipa.c, linux-i386-ipa.c, linux-low.c, linux-tic6x-low.c, linux-x86-low.c, linux-x86-tdesc-selftest.c, linux-x86-tdesc.c, lynx-i386-low.c, lynx-low.c, mem-break.h, nto-x86-low.c, regcache.c, regcache.h, remote-utils.c, server.c, server.h, spu-low.c, symbol.c, target.h, tdesc.c, tdesc.h, thread-db.c, tracepoint.c, win32-i386-low.c, win32-low.c: Change common to gdbsupport. |
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| 113b7b8142 |
gdb/riscv: Split ISA and ABI features
The goal of this commit is to allow RV64 binaries compiled for the 'F'
extension to run on a target that supports both the 'F' and 'D'
extensions.
The 'D' extension depends on the 'F' extension and chapter 9 of the
RISC-V ISA manual implies that running a program compiled for 'F' on
a 'D' target should be fine.
To support this the gdbarch now holds two feature sets, one represents
the features that are present on the target, and one represents the
features requested in the ELF flags.
The existing error checks are relaxed slightly to allow binaries
compiled for 32-bit 'F' extension to run on targets with the 64-bit
'D' extension.
A new set of functions called riscv_abi_{xlen,flen} are added to
compliment the existing riscv_isa_{xlen,flen}, and some callers to the
isa functions now call the abi functions when that is appropriate.
In riscv_call_arg_struct two asserts are removed, these asserts no
longer make sense. The asserts were both like this:
gdb_assert (TYPE_LENGTH (ainfo->type)
<= (cinfo->flen + cinfo->xlen));
And were made in two cases, when passing structures like these:
struct {
integer field1;
float field2;
};
or,
struct {
float field1;
integer field2;
};
When running on an RV64 target which only has 32-bit float then the
integer field could be 64-bits, while if the float field is 32-bits
the overall size of the structure can be 128-bits (with 32-bits of
padding). In this case the assertion would fail, however, the code
isn't incorrect, so its safe to just remove the assertion.
This was tested by running on an RV64IMFDC target using a compiler
configured for RV64IMFC, and comparing the results with those obtained
when using a compiler configured for RV64IMFDC. The only regressions
I see (now) are in gdb.base/store.exp and are related too different
code generation choices GCC makes between the two targets.
Finally, this commit does not make any attempt to support running
binaries compiled for RV32 on an RV64 target, though nothing in here
should prevent that being supported in the future.
gdb/ChangeLog:
* arch/riscv.h (struct riscv_gdbarch_features) <hw_float_abi>:
Delete.
<operator==>: Update with for removed field.
<hash>: Likewise.
* riscv-tdep.h (struct gdbarch_tdep) <features>: Renamed to...
<isa_features>: ...this.
<abi_features>: New field.
(riscv_isa_flen): Update comment.
(riscv_abi_xlen): New declaration.
(riscv_abi_flen): New declaration.
* riscv-tdep.c (riscv_isa_xlen): Update to get answer from
isa_features.
(riscv_abi_xlen): New function.
(riscv_isa_flen): Update to get answer from isa_features.
(riscv_abi_flen): New function.
(riscv_has_fp_abi): Update to get answer from abi_features.
(riscv_call_info::riscv_call_info): Use abi xlen and flen, not isa
xlen and flen.
(riscv_call_info) <xlen, flen>: Update comment.
(riscv_call_arg_struct): Remove invalid assertions
(riscv_features_from_gdbarch_info): Update now hw_float_abi field
is removed.
(riscv_gdbarch_init): Gather isa features and abi features
separately, ensure both match on the gdbarch when reusing an old
gdbarch. Relax an error check to allow 32-bit abi float to run on
a target with 64-bit float hardware.
|
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| 42a4f53d2b |
Update copyright year range in all GDB files.
This commit applies all changes made after running the gdb/copyright.py script. Note that one file was flagged by the script, due to an invalid copyright header (gdb/unittests/basic_string_view/element_access/char/empty.cc). As the file was copied from GCC's libstdc++-v3 testsuite, this commit leaves this file untouched for the time being; a patch to fix the header was sent to gcc-patches first. gdb/ChangeLog: Update copyright year range in all GDB files. |
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| 634494366c |
gdb/riscv: Create each unique target description only once
GDB relies on the fact that if two target descriptions have the same contents, then they will be the same object instance (having the same address). One place where this is a requirement is in GDBARCH_LIST_LOOKUP_BY_INFO which is used to find previously created gdbarch objects. In GDBARCH_LIST_LOOKUP_BY_INFO a pointer comparison is made on the gdbarch's target description, if the pointers are different then it is assumed the gdbarches have different, non-compatible target descriptions. Previously we would create duplicate target descriptions in the belief that RISCV_GDBARCH_INIT would spot this duplication and discard the second instance. However, this was incorrect, and instead we ended up creating duplicate gdbarch objects. With this commit every unique feature set will create one and only one target description, the feature set and resulting target description is then cached so that the same target description object can be returned later. Many other target avoid this problem by creating a small number of named target descriptions, and returning one of these. However, we currently have 8 possible target descriptions (32 vs 64 bit for x-reg and f-reg, and h/w or s/w float abi) and creating each of these just to avoid a dynamic cache seems pointless. gdb/ChangeLog: * arch/riscv.h (riscv_gdbarch_features::hash): New method. * arch/riscv.c (struct riscv_gdbarch_features_hasher): New. (riscv_tdesc_cache): New global. (riscv_create_target_description): Look in the cache before creating a new target description. |
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| 65a4b37326 |
gdb/riscv: Add equality operators to riscv_gdb_features
Add '==' and '!=' operators for the struct riscv_gdb_features, allowing a small simplification. gdb/ChangeLog: * arch/riscv.h (riscv_gdb_features::operator==): New. (riscv_gdb_features::operator!=): New. * riscv-tdep.c (riscv_gdbarch_init): Make use of the inequality operator. |
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| 0ff80bf7b9 |
gdb/riscv: Make some target description functions constant
Makes more of the interface related to fetching target descriptions constant. gdb/ChangeLog: * arch/riscv.h (riscv_create_target_description): Make return type const. * arch/riscv.c (riscv_create_target_description): Likewise. * riscv-tdep.c (riscv_find_default_target_description): Likewise. |
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| b5ffee3181 |
gdb/riscv: Add target description support
This commit adds target description support for riscv. I've used the split feature approach for specifying the architectural features, and the CSR feature is auto-generated from the riscv-opc.h header file. If the target doesn't provide a suitable target description then GDB will build one by looking at the bfd headers. This commit does not implement target description creation for the Linux or FreeBSD native targets, both of these will need to add read_description methods into their respective target classes, which probe the target features, and then call riscv_create_target_description to build a suitable target description. Until this is done Linux and FreeBSD will get the same default target description based on the bfd that bare-metal targets get. I've only added feature descriptions for 32 and 64 bit registers, 128 bit registers (for RISC-V) are not supported in the reset of GDB yet. This commit removes the special reading of the MISA register in order to establish the target features, this was only used for figuring out the f-register size, and even that wasn't done consistently. We now rely on the target to tell us what size of registers it has (or look in the BFD as a last resort). The result of this is that we should now support RV64 targets with 32-bit float, though I have not extensively tested this combination yet. * Makefile.in (ALL_TARGET_OBS): Add arch/riscv.o. (HFILES_NO_SRCDIR): Add arch/riscv.h. * arch/riscv.c: New file. * arch/riscv.h: New file. * configure.tgt: Add cpu_obs list of riscv, move riscv-tdep.o into this list, and add arch/riscv.o. * features/Makefile: Add riscv features. * features/riscv/32bit-cpu.c: New file. * features/riscv/32bit-cpu.xml: New file. * features/riscv/32bit-csr.c: New file. * features/riscv/32bit-csr.xml: New file. * features/riscv/32bit-fpu.c: New file. * features/riscv/32bit-fpu.xml: New file. * features/riscv/64bit-cpu.c: New file. * features/riscv/64bit-cpu.xml: New file. * features/riscv/64bit-csr.c: New file. * features/riscv/64bit-csr.xml: New file. * features/riscv/64bit-fpu.c: New file. * features/riscv/64bit-fpu.xml: New file. * features/riscv/rebuild-csr-xml.sh: New file. * riscv-tdep.c: Add 'arch/riscv.h' include. (riscv_gdb_reg_names): Delete. (csr_reggroup): New global. (struct riscv_register_alias): Delete. (struct riscv_register_feature): New structure. (riscv_register_aliases): Delete. (riscv_xreg_feature): New global. (riscv_freg_feature): New global. (riscv_virtual_feature): New global. (riscv_csr_feature): New global. (riscv_create_csr_aliases): New function. (riscv_read_misa_reg): Delete. (riscv_has_feature): Delete. (riscv_isa_xlen): Simplify, just return cached xlen. (riscv_isa_flen): Simplify, just return cached flen. (riscv_has_fp_abi): Update for changes in struct gdbarch_tdep. (riscv_register_name): Update to make use of tdesc_register_name. Look up xreg and freg names in the new globals riscv_xreg_feature and riscv_freg_feature. Don't supply csr aliases here. (riscv_fpreg_q_type): Delete. (riscv_register_type): Use tdesc_register_type in almost all cases, override the returned type in a few specific cases only. (riscv_print_one_register_info): Handle errors reading registers. (riscv_register_reggroup_p): Use tdesc_register_in_reggroup_p for registers that are otherwise unknown to GDB. Also check the csr_reggroup. (riscv_print_registers_info): Remove assert about upper register number, and use gdbarch_register_reggroup_p instead of short-cutting. (riscv_find_default_target_description): New function. (riscv_check_tdesc_feature): New function. (riscv_add_reggroups): New function. (riscv_setup_register_aliases): New function. (riscv_init_reggroups): New function. (_initialize_riscv_tdep): Add calls to setup CSR aliases, and setup register groups. Register new riscv debug variable. * riscv-tdep.h: Add 'arch/riscv.h' include. (struct gdbarch_tdep): Remove abi union, and add riscv_gdbarch_features field. Remove cached quad floating point type, and provide initialisation for double type field. * target-descriptions.c (maint_print_c_tdesc_cmd): Add riscv to the list of targets using the feature based target descriptions. * NEWS: Mention target description support. gdb/doc/ChangeLog: * gdb.texinfo (Standard Target Features): Add RISC-V Features sub-section. |
