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Re: [PING] [PATCH v2] Make ada_decode not use a static buffer
- From: "Christian Biesinger via gdb-patches" <gdb-patches at sourceware dot org>
- To: gdb-patches <gdb-patches at sourceware dot org>
- Date: Thu, 19 Sep 2019 07:06:09 +0900
- Subject: Re: [PING] [PATCH v2] Make ada_decode not use a static buffer
- References: <20190828204536.251120-1-cbiesinger@google.com> <20190828212442.204696-1-cbiesinger@google.com> <CAPTJ0XH+_j5xpWg1cMwMspw8D+kpC3s6HmCsQL3=i5dLiqFOLA@mail.gmail.com>
- Reply-to: Christian Biesinger <cbiesinger at google dot com>
Ping
On Thu, Sep 12, 2019, 00:04 Christian Biesinger <cbiesinger@google.com>
wrote:
> ping
>
> On Wed, Aug 28, 2019 at 4:24 PM Christian Biesinger
> <cbiesinger@google.com> wrote:
> >
> > [Fixes an issue with the previous version.]
> >
> > This makes it safer to use in general, and also allows using it on a
> > background thread in the future.
> >
> > Inspired by tromey's patch at:
> >
> https://github.com/tromey/gdb/commit/1226cbdfa436297a5dec054d94592c45891afa93
> > (however, implemented in a different way)
> >
> > gdb/ChangeLog:
> >
> > 2019-08-28 Christian Biesinger <cbiesinger@google.com>
> >
> > * ada-exp.y (write_object_remaining): Update.
> > * ada-lang.c (ada_decode): Return a std::string instead of a
> char*
> > and eliminate the static buffer.
> > (ada_decode_symbol): Update.
> > (ada_la_decode): Update.
> > (ada_sniff_from_mangled_name): Update.
> > (is_valid_name_for_wild_match): Update.
> > (ada_lookup_name_info::matches): Update and simplify.
> > (name_matches_regex): Update.
> > (ada_add_global_exceptions): Update.
> > * ada-lang.h (ada_decode): Update signature.
> > * ada-varobj.c (ada_varobj_describe_simple_array_child): Update.
> > ---
> > gdb/ada-exp.y | 2 +-
> > gdb/ada-lang.c | 63 ++++++++++++++++++------------------------------
> > gdb/ada-lang.h | 2 +-
> > gdb/ada-varobj.c | 6 ++++-
> > 4 files changed, 31 insertions(+), 42 deletions(-)
> >
> > diff --git a/gdb/ada-exp.y b/gdb/ada-exp.y
> > index c8a7b9c9c7..160e64bc05 100644
> > --- a/gdb/ada-exp.y
> > +++ b/gdb/ada-exp.y
> > @@ -816,7 +816,7 @@ write_object_renaming (struct parser_state
> *par_state,
> > renamed_entity_len);
> > ada_lookup_encoded_symbol (name, orig_left_context, VAR_DOMAIN,
> &sym_info);
> > if (sym_info.symbol == NULL)
> > - error (_("Could not find renamed variable: %s"), ada_decode (name));
> > + error (_("Could not find renamed variable: %s"), ada_decode
> (name).c_str ());
> > else if (SYMBOL_CLASS (sym_info.symbol) == LOC_TYPEDEF)
> > /* We have a renaming of an old-style renaming symbol. Don't
> > trust the block information. */
> > diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
> > index 609f2d4391..e4e9604294 100644
> > --- a/gdb/ada-lang.c
> > +++ b/gdb/ada-lang.c
> > @@ -1105,22 +1105,16 @@ ada_remove_po_subprogram_suffix (const char
> *encoded, int *len)
> >
> > /* If ENCODED follows the GNAT entity encoding conventions, then return
> > the decoded form of ENCODED. Otherwise, return "<%s>" where "%s" is
> > - replaced by ENCODED.
> > + replaced by ENCODED. */
> >
> > - The resulting string is valid until the next call of ada_decode.
> > - If the string is unchanged by decoding, the original string pointer
> > - is returned. */
> > -
> > -const char *
> > +std::string
> > ada_decode (const char *encoded)
> > {
> > int i, j;
> > int len0;
> > const char *p;
> > - char *decoded;
> > int at_start_name;
> > - static char *decoding_buffer = NULL;
> > - static size_t decoding_buffer_size = 0;
> > + std::string decoded;
> >
> > /* With function descriptors on PPC64, the value of a symbol named
> > ".FN", if it exists, is the entry point of the function "FN". */
> > @@ -1179,8 +1173,7 @@ ada_decode (const char *encoded)
> >
> > /* Make decoded big enough for possible expansion by operator name.
> */
> >
> > - GROW_VECT (decoding_buffer, decoding_buffer_size, 2 * len0 + 1);
> > - decoded = decoding_buffer;
> > + decoded.resize (2 * len0 + 1, 'X');
> >
> > /* Remove trailing __{digit}+ or trailing ${digit}+. */
> >
> > @@ -1217,7 +1210,7 @@ ada_decode (const char *encoded)
> > op_len - 1) == 0)
> > && !isalnum (encoded[i + op_len]))
> > {
> > - strcpy (decoded + j, ada_opname_table[k].decoded);
> > + strcpy (&decoded.front() + j,
> ada_opname_table[k].decoded);
> > at_start_name = 0;
> > i += op_len;
> > j += strlen (ada_opname_table[k].decoded);
> > @@ -1338,27 +1331,22 @@ ada_decode (const char *encoded)
> > j += 1;
> > }
> > }
> > - decoded[j] = '\000';
> > + decoded.resize (j);
> >
> > /* Decoded names should never contain any uppercase character.
> > Double-check this, and abort the decoding if we find one. */
> >
> > - for (i = 0; decoded[i] != '\0'; i += 1)
> > + for (i = 0; i < decoded.length(); ++i)
> > if (isupper (decoded[i]) || decoded[i] == ' ')
> > goto Suppress;
> >
> > - if (strcmp (decoded, encoded) == 0)
> > - return encoded;
> > - else
> > - return decoded;
> > + return decoded;
> >
> > Suppress:
> > - GROW_VECT (decoding_buffer, decoding_buffer_size, strlen (encoded) +
> 3);
> > - decoded = decoding_buffer;
> > if (encoded[0] == '<')
> > - strcpy (decoded, encoded);
> > + decoded = encoded;
> > else
> > - xsnprintf (decoded, decoding_buffer_size, "<%s>", encoded);
> > + decoded = '<' + std::string(encoded) + '>';
> > return decoded;
> >
> > }
> > @@ -1389,13 +1377,13 @@ ada_decode_symbol (const struct
> general_symbol_info *arg)
> >
> > if (!gsymbol->ada_mangled)
> > {
> > - const char *decoded = ada_decode (gsymbol->name);
> > + std::string decoded = ada_decode (gsymbol->name);
> > struct obstack *obstack = gsymbol->language_specific.obstack;
> >
> > gsymbol->ada_mangled = 1;
> >
> > if (obstack != NULL)
> > - *resultp = obstack_strdup (obstack, decoded);
> > + *resultp = obstack_strdup (obstack, decoded.c_str ());
> > else
> > {
> > /* Sometimes, we can't find a corresponding objfile, in
> > @@ -1404,10 +1392,10 @@ ada_decode_symbol (const struct
> general_symbol_info *arg)
> > significant memory leak (FIXME). */
> >
> > char **slot = (char **) htab_find_slot (decoded_names_store,
> > - decoded, INSERT);
> > + decoded.c_str (),
> INSERT);
> >
> > if (*slot == NULL)
> > - *slot = xstrdup (decoded);
> > + *slot = xstrdup (decoded.c_str ());
> > *resultp = *slot;
> > }
> > }
> > @@ -1418,7 +1406,7 @@ ada_decode_symbol (const struct
> general_symbol_info *arg)
> > static char *
> > ada_la_decode (const char *encoded, int options)
> > {
> > - return xstrdup (ada_decode (encoded));
> > + return xstrdup (ada_decode (encoded).c_str ());
> > }
> >
> > /* Implement la_sniff_from_mangled_name for Ada. */
> > @@ -1426,11 +1414,11 @@ ada_la_decode (const char *encoded, int options)
> > static int
> > ada_sniff_from_mangled_name (const char *mangled, char **out)
> > {
> > - const char *demangled = ada_decode (mangled);
> > + std::string demangled = ada_decode (mangled);
> >
> > *out = NULL;
> >
> > - if (demangled != mangled && demangled != NULL && demangled[0] != '<')
> > + if (demangled != mangled && demangled[0] != '<')
> > {
> > /* Set the gsymbol language to Ada, but still return 0.
> > Two reasons for that:
> > @@ -5995,7 +5983,7 @@ is_name_suffix (const char *str)
> > static int
> > is_valid_name_for_wild_match (const char *name0)
> > {
> > - const char *decoded_name = ada_decode (name0);
> > + std::string decoded_name = ada_decode (name0);
> > int i;
> >
> > /* If the decoded name starts with an angle bracket, it means that
> > @@ -6241,13 +6229,10 @@ ada_lookup_name_info::matches
> > that iff we are doing a verbatim match, the decoded version
> > of the symbol name starts with '<'. Otherwise, this symbol
> name
> > is not a suitable completion. */
> > - const char *sym_name_copy = sym_name;
> > - bool has_angle_bracket;
> >
> > - sym_name = ada_decode (sym_name);
> > - has_angle_bracket = (sym_name[0] == '<');
> > + std::string decoded = ada_decode (sym_name);
> > + bool has_angle_bracket = (decoded[0] == '<');
> > match = (has_angle_bracket == m_verbatim_p);
> > - sym_name = sym_name_copy;
> > }
> >
> > if (match && !m_verbatim_p)
> > @@ -6271,7 +6256,7 @@ ada_lookup_name_info::matches
> > /* Since we are doing wild matching, this means that TEXT
> > may represent an unqualified symbol name. We therefore must
> > also compare TEXT against the unqualified name of the symbol.
> */
> > - sym_name = ada_unqualified_name (ada_decode (sym_name));
> > + sym_name = ada_unqualified_name (ada_decode (sym_name).c_str ());
> >
> > if (strncmp (sym_name, text, text_len) == 0)
> > match = true;
> > @@ -13496,7 +13481,7 @@ static bool
> > name_matches_regex (const char *name, compiled_regex *preg)
> > {
> > return (preg == NULL
> > - || preg->exec (ada_decode (name), 0, NULL, 0) == 0);
> > + || preg->exec (ada_decode (name).c_str (), 0, NULL, 0) == 0);
> > }
> >
> > /* Add all exceptions defined globally whose name name match
> > @@ -13529,8 +13514,8 @@ ada_add_global_exceptions (compiled_regex *preg,
> > lookup_name_info::match_any (),
> > [&] (const char *search_name)
> > {
> > - const char *decoded = ada_decode
> (search_name);
> > - return name_matches_regex (decoded, preg);
> > + std::string decoded = ada_decode
> (search_name);
> > + return name_matches_regex (decoded.c_str
> (), preg);
> > },
> > NULL,
> > VARIABLES_DOMAIN);
> > diff --git a/gdb/ada-lang.h b/gdb/ada-lang.h
> > index 2fc3f523ca..c7279d5ac3 100644
> > --- a/gdb/ada-lang.h
> > +++ b/gdb/ada-lang.h
> > @@ -227,7 +227,7 @@ extern struct type *ada_get_decoded_type (struct
> type *type);
> >
> > extern const char *ada_decode_symbol (const struct general_symbol_info
> *);
> >
> > -extern const char *ada_decode (const char*);
> > +extern std::string ada_decode (const char*);
> >
> > extern enum language ada_update_initial_language (enum language);
> >
> > diff --git a/gdb/ada-varobj.c b/gdb/ada-varobj.c
> > index a4d553d378..1a5d0ac239 100644
> > --- a/gdb/ada-varobj.c
> > +++ b/gdb/ada-varobj.c
> > @@ -624,6 +624,7 @@ ada_varobj_describe_simple_array_child (struct value
> *parent_value,
> > of the array index type when such type qualification is
> > needed. */
> > const char *index_type_name = NULL;
> > + std::string decoded;
> >
> > /* If the index type is a range type, find the base type. */
> > while (TYPE_CODE (index_type) == TYPE_CODE_RANGE)
> > @@ -634,7 +635,10 @@ ada_varobj_describe_simple_array_child (struct
> value *parent_value,
> > {
> > index_type_name = ada_type_name (index_type);
> > if (index_type_name)
> > - index_type_name = ada_decode (index_type_name);
> > + {
> > + decoded = ada_decode (index_type_name);
> > + index_type_name = decoded.c_str ();
> > + }
> > }
> >
> > if (index_type_name != NULL)
> > --
> > 2.23.0.187.g17f5b7556c-goog
> >
>