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author | Tom Tromey <tom@tromey.com> | 2016-06-03 14:11:08 -0600 |
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committer | Tom Tromey <tom@tromey.com> | 2016-07-26 13:43:27 -0600 |
commit | 0b31a4bcec2efec9bc8ca40deb61123c52690a2e (patch) | |
tree | 174c97fc33b15c671836a0d5f8744b8981dbb7bf /gdb/symtab.h | |
parent | 8484fb75874eb9ef35710ac6579433f062ddba18 (diff) | |
download | gdb-0b31a4bcec2efec9bc8ca40deb61123c52690a2e.zip gdb-0b31a4bcec2efec9bc8ca40deb61123c52690a2e.tar.gz gdb-0b31a4bcec2efec9bc8ca40deb61123c52690a2e.tar.bz2 |
PR python/20190 - compute TLS symbol without a frame
PR python/20190 arose from an exception I noticed when trying to use
the Python unwinder for Spider Monkey in Firefox.
The problem is that the unwinder wants to examine the value of a
thread-local variable. However, sympy_value rejects this because
symbol_read_needs_frame returns true for a TLS variable.
This problem arose once before, though in a different context:
https://sourceware.org/bugzilla/show_bug.cgi?id=11803
At the time Pedro and Daniel pointed out a simpler way to fix that bug
(see links in 20190 if you are interested); but for this new bug I
couldn't think of a similar fix and ended up implementing Daniel's
other suggestion:
https://sourceware.org/ml/gdb-patches/2010-07/msg00393.html
That is, this patch makes it possible to detect whether a symbol needs
a specific frame, or whether it just needs the inferior to have
registers.
Built and regtested on x86-64 Fedora 24.
2016-07-26 Tom Tromey <tom@tromey.com>
* symtab.c (register_symbol_computed_impl): Update.
PR python/20190:
* value.h (symbol_read_needs): Declare.
(symbol_read_needs_frame): Add comment.
* symtab.h (struct symbol_computed_ops) <read_variable>: Update
comment.
<get_symbol_read_needs>: Rename. Change return type.
* findvar.c (symbol_read_needs): New function.
(symbol_read_needs_frame): Rewrite.
(default_read_var_value): Use symbol_read_needs.
* dwarf2loc.c (struct symbol_needs_baton): Rename.
<needs>: Renamed from needs_frame. Changed type.
(needs_frame_read_addr_from_reg, symbol_needs_get_reg_value)
(symbol_needs_read_mem, symbol_needs_frame_base)
(symbol_needs_frame_cfa, symbol_needs_tls_address)
(symbol_needs_dwarf_call): Rename.
(needs_dwarf_reg_entry_value): Update.
(symbol_needs_ctx_funcs, dwarf2_loc_desc_get_symbol_read_needs):
Rename and update.
(locexpr_get_symbol_read_needs, loclist_symbol_needs): Likewise.
(dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Update.
* defs.h (enum symbol_needs_kind): New.
2016-07-26 Tom Tromey <tom@tromey.com>
PR python/20190:
* gdb.threads/tls.exp (check_thread_local): Add python symbol
test.
Diffstat (limited to 'gdb/symtab.h')
-rw-r--r-- | gdb/symtab.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/gdb/symtab.h b/gdb/symtab.h index 6f00baf..9df4efb 100644 --- a/gdb/symtab.h +++ b/gdb/symtab.h @@ -629,7 +629,8 @@ struct symbol_computed_ops frame FRAME. If the variable has been optimized out, return zero. - Iff `read_needs_frame (SYMBOL)' is zero, then FRAME may be zero. */ + Iff `read_needs_frame (SYMBOL)' is not SYMBOL_NEEDS_FRAME, then + FRAME may be zero. */ struct value *(*read_variable) (struct symbol * symbol, struct frame_info * frame); @@ -640,8 +641,11 @@ struct symbol_computed_ops struct value *(*read_variable_at_entry) (struct symbol *symbol, struct frame_info *frame); - /* Return non-zero if we need a frame to find the value of the SYMBOL. */ - int (*read_needs_frame) (struct symbol * symbol); + /* Find the "symbol_needs_kind" value for the given symbol. This + value determines whether reading the symbol needs memory (e.g., a + global variable), just registers (a thread-local), or a frame (a + local variable). */ + enum symbol_needs_kind (*get_symbol_read_needs) (struct symbol * symbol); /* Write to STREAM a natural-language description of the location of SYMBOL, in the context of ADDR. */ |