From: Pedro Alves Date: Wed, 4 Oct 2017 17:21:09 +0000 (+0100) Subject: Redesign mock environment for gdbarch selftests X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=55b11ddf16b97b9c50ed480bc9da8b3e1c6c4198;p=binutils-gdb.git Redesign mock environment for gdbarch selftests A following patch will remove this hack from within regcache's implementation: struct regcache * get_thread_arch_regcache (ptid_t ptid, struct gdbarch *gdbarch) { struct address_space *aspace; /* For the benefit of "maint print registers" & co when debugging an executable, allow dumping the regcache even when there is no thread selected (target_thread_address_space internal-errors if no address space is found). Note that normal user commands will fail higher up on the call stack due to no target_has_registers. */ aspace = (ptid_equal (null_ptid, ptid) ? NULL : target_thread_address_space (ptid)); i.e., it'll no longer be possible to try to build a regcache for null_ptid. That change alone would regress the gdbarch self tests though, causing this: (gdb) maintenance selftest [...] Running selftest register_to_value. src/gdb/inferior.c:309: internal-error: inferior* find_inferior_pid(int): Assertion `pid != 0' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) FAIL: gdb.gdb/unittest.exp: maintenance selftest (GDB internal error) The problem is that the way the mocking environment for those unit tests is written is a bit fragile: it creates a special purpose regcache (and sentinel's frame), using whatever is the current inferior_ptid (usually null_ptid), and assumes get_current_regcache will find that in the regcache::current_regcache list. This commit changes the way the mock environment is created. It eliminates the special regcache and frame and instead creates a fuller mock environment, with a custom mock target_ops, and then a mock inferior and thread "running" on that target. If there's already a running target when you type "maint selftest", then we error out, instead of pushing a new target on top of the existing one (and thus killing the debug session). This results in: (gdb) maint selftest (...) Self test failed: arch i386: target already pushed Self test failed: arch i386:x86-64: target already pushed Self test failed: arch i386:x64-32: target already pushed Self test failed: arch i8086: target already pushed Self test failed: arch i386:intel: target already pushed Self test failed: arch i386:x86-64:intel: target already pushed Self test failed: arch i386:x64-32:intel: target already pushed Self test failed: arch i386:nacl: target already pushed Self test failed: arch i386:x86-64:nacl: target already pushed Self test failed: arch i386:x64-32:nacl: target already pushed Self test failed: self-test failed at /home/pedro/gdb/mygit/src/gdb/selftest-arch.c:86 (...) Ran 19 unit tests, 1 failed I think that's OK, because self tests are really meant to be run from a clean state right after GDB is started. I'm adding that erroring out just as safe measure just in case someone types "maint selftest" on the command line while already debugging something (as I've done it). (In my multi-target branch, where this patch originated from, we don't actually need to error out, because there each inferior has its own target stack). Also, note that the current code was doing: current_inferior()->gdbarch = gdbarch; without taking care to restore the previous gdbarch. This means that GDB's state was being left inconsistent after running the self tests, further supporting the point that there's probably not much expectation that mixing "maint selftests" and regular debugging in the same GDB invocation really works. This patch fixes that, regardless. gdb/ChangeLog: 2017-10-04 Pedro Alves * frame.c (create_test_frame): Delete. * frame.h (create_test_frame): Delete. * gdbarch-selftests.c: Include gdbthread.h and target.h. (class regcache_test): Delete. (test_target_has_registers, test_target_has_stack) (test_target_has_memory, test_target_prepare_to_store) (test_target_store_registers): New functions. (test_target_ops): New class. (register_to_value_test): Error out if there's already a process_stratum (or higher) target pushed. Create a fuller mock environment, with mock target_ops, inferior, address space, thread and inferior_ptid. * progspace.c (struct address_space): Move to ... * progspace.h (struct address_space): ... here. * regcache.h (regcache::~regcache, regcache::raw_write) [GDB_SELF_TEST]: No longer virtual. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 37d86aee9e6..726dbc787dc 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,22 @@ +2017-10-04 Pedro Alves + + * frame.c (create_test_frame): Delete. + * frame.h (create_test_frame): Delete. + * gdbarch-selftests.c: Include gdbthread.h and target.h. + (class regcache_test): Delete. + (test_target_has_registers, test_target_has_stack) + (test_target_has_memory, test_target_prepare_to_store) + (test_target_store_registers): New functions. + (test_target_ops): New class. + (register_to_value_test): Error out if there's already a + process_stratum (or higher) target pushed. Create a fuller mock + environment, with mock target_ops, inferior, address space, thread + and inferior_ptid. + * progspace.c (struct address_space): Move to ... + * progspace.h (struct address_space): ... here. + * regcache.h (regcache::~regcache, regcache::raw_write) + [GDB_SELF_TEST]: No longer virtual. + 2017-10-04 Simon Marchi * mi/mi-main.c (list_available_thread_groups): Reverse filter logic. diff --git a/gdb/frame.c b/gdb/frame.c index a74deef7ed2..afdc157ebd0 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -1716,23 +1716,6 @@ select_frame (struct frame_info *fi) } } -#if GDB_SELF_TEST -struct frame_info * -create_test_frame (struct regcache *regcache) -{ - struct frame_info *this_frame = XCNEW (struct frame_info); - - sentinel_frame = create_sentinel_frame (NULL, regcache); - sentinel_frame->prev = this_frame; - sentinel_frame->prev_p = 1;; - this_frame->prev_arch.p = 1; - this_frame->prev_arch.arch = get_regcache_arch (regcache); - this_frame->next = sentinel_frame; - - return this_frame; -} -#endif - /* Create an arbitrary (i.e. address specified by user) or innermost frame. Always returns a non-NULL value. */ diff --git a/gdb/frame.h b/gdb/frame.h index 024985762df..1b726108b99 100644 --- a/gdb/frame.h +++ b/gdb/frame.h @@ -833,14 +833,6 @@ extern struct frame_info *deprecated_safe_get_selected_frame (void); extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc); -#if GDB_SELF_TEST - -/* Create a frame for unit test. Its next frame is sentinel frame, - created from REGCACHE. */ - -extern struct frame_info *create_test_frame (struct regcache *regcache); -#endif - /* Return true if the frame unwinder for frame FI is UNWINDER; false otherwise. */ diff --git a/gdb/gdbarch-selftests.c b/gdb/gdbarch-selftests.c index f0b8d5d0563..58ed11287a0 100644 --- a/gdb/gdbarch-selftests.c +++ b/gdb/gdbarch-selftests.c @@ -22,25 +22,57 @@ #include "selftest.h" #include "selftest-arch.h" #include "inferior.h" +#include "gdbthread.h" +#include "target.h" namespace selftests { -/* A read-write regcache which doesn't write the target. */ +/* A mock process_stratum target_ops that doesn't read/write registers + anywhere. */ -class regcache_test : public regcache +static int +test_target_has_registers (target_ops *self) { -public: - explicit regcache_test (struct gdbarch *gdbarch) - : regcache (gdbarch, NULL, false) - { - set_ptid (inferior_ptid); + return 1; +} - current_regcache.push_front (this); - } +static int +test_target_has_stack (target_ops *self) +{ + return 1; +} + +static int +test_target_has_memory (target_ops *self) +{ + return 1; +} + +static void +test_target_prepare_to_store (target_ops *self, regcache *regs) +{ +} + +static void +test_target_store_registers (target_ops *self, regcache *regs, int regno) +{ +} - void raw_write (int regnum, const gdb_byte *buf) override +class test_target_ops : public target_ops +{ +public: + test_target_ops () + : target_ops {} { - raw_set_cached_value (regnum, buf); + to_magic = OPS_MAGIC; + to_stratum = process_stratum; + to_has_memory = test_target_has_memory; + to_has_stack = test_target_has_stack; + to_has_registers = test_target_has_registers; + to_prepare_to_store = test_target_prepare_to_store; + to_store_registers = test_target_store_registers; + + complete_target_initialization (this); } }; @@ -84,15 +116,56 @@ register_to_value_test (struct gdbarch *gdbarch) builtin->builtin_char32, }; - current_inferior()->gdbarch = gdbarch; + /* Error out if debugging something, because we're going to push the + test target, which would pop any existing target. */ + if (current_target.to_stratum >= process_stratum) + error (_("target already pushed")); + + /* Create a mock environment. An inferior with a thread, with a + process_stratum target pushed. */ + + test_target_ops mock_target; + ptid_t mock_ptid (1, 1); + inferior mock_inferior (mock_ptid.pid ()); + address_space mock_aspace {}; + mock_inferior.gdbarch = gdbarch; + mock_inferior.aspace = &mock_aspace; + thread_info mock_thread (&mock_inferior, mock_ptid); + + scoped_restore restore_thread_list + = make_scoped_restore (&thread_list, &mock_thread); + + /* Add the mock inferior to the inferior list so that look ups by + target+ptid can find it. */ + scoped_restore restore_inferior_list + = make_scoped_restore (&inferior_list); + inferior_list = &mock_inferior; + + /* Switch to the mock inferior. */ + scoped_restore_current_inferior restore_current_inferior; + set_current_inferior (&mock_inferior); + + /* Push the process_stratum target so we can mock accessing + registers. */ + push_target (&mock_target); + + /* Pop it again on exit (return/exception). */ + struct on_exit + { + ~on_exit () + { + pop_all_targets_at_and_above (process_stratum); + } + } pop_targets; + + /* Switch to the mock thread. */ + scoped_restore restore_inferior_ptid + = make_scoped_restore (&inferior_ptid, mock_ptid); - struct regcache *regcache = new regcache_test (gdbarch); - struct frame_info *frame = create_test_frame (regcache); + struct frame_info *frame = get_current_frame (); const int num_regs = (gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch)); - SELF_CHECK (regcache == get_current_regcache ()); - /* Test gdbarch methods register_to_value and value_to_register with different combinations of register numbers and types. */ for (const auto &type : types) diff --git a/gdb/progspace.c b/gdb/progspace.c index 41e8cd0e714..ea328c82076 100644 --- a/gdb/progspace.c +++ b/gdb/progspace.c @@ -44,18 +44,6 @@ static int highest_address_space_num; DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD) -/* An address space. It is used for comparing if pspaces/inferior/threads - see the same address space and for associating caches to each address - space. */ - -struct address_space -{ - int num; - - /* Per aspace data-pointers required by other GDB modules. */ - REGISTRY_FIELDS; -}; - /* Keep a registry of per-address_space data-pointers required by other GDB modules. */ diff --git a/gdb/progspace.h b/gdb/progspace.h index f679fe3f711..85c99a62091 100644 --- a/gdb/progspace.h +++ b/gdb/progspace.h @@ -210,6 +210,17 @@ struct program_space REGISTRY_FIELDS; }; +/* An address space. It is used for comparing if + pspaces/inferior/threads see the same address space and for + associating caches to each address space. */ +struct address_space +{ + int num; + + /* Per aspace data-pointers required by other GDB modules. */ + REGISTRY_FIELDS; +}; + /* The object file that the main symbol table was loaded from (e.g. the argument to the "symbol-file" or "file" command). */ diff --git a/gdb/regcache.h b/gdb/regcache.h index 3ecdb3b1a32..6f42fb93769 100644 --- a/gdb/regcache.h +++ b/gdb/regcache.h @@ -252,11 +252,6 @@ public: DISABLE_COPY_AND_ASSIGN (regcache); - /* class regcache is only extended in unit test, so only mark it - virtual when selftest is enabled. */ -#if GDB_SELF_TEST - virtual -#endif ~regcache () { xfree (m_registers); @@ -277,11 +272,6 @@ public: enum register_status raw_read (int regnum, gdb_byte *buf); - /* class regcache is only extended in unit test, so only mark it - virtual when selftest is enabled. */ -#if GDB_SELF_TEST - virtual -#endif void raw_write (int regnum, const gdb_byte *buf); template>