New gold plugin interface for getting --wrap symbols
Sriraman Tallam via binutils
binutils@sourceware.org
Sat Dec 2 00:10:00 GMT 2017
On Mon, Nov 27, 2017 at 10:31 PM, Cary Coutant <ccoutant@gmail.com> wrote:
>>> LLVM ThinLTO needs a gold plugin API to get the list of symbols that
>>> are wrapped using the --wrap option to avoid garbage collection of some of
>>> the associated functions like __wrap_symbol and __real_symbol.
>>>
>>> This patch adds an interface, get_wrap_symbols, to get the count and
>>> the list of symbols that are wrapped.
>
> There's a difference between the list of --wrap options passed to the
> linker (which is what this API returns), and a list of which symbols
> actually got wrapped. How is this useful compared to simply
> pattern-matching for symbols whose name begins with "__wrap" and
> "__real" (which will give you the symbols that were actually wrapped)?
>
> Assuming this is what you want...
>
> + std::vector<const char *> wrapped_symbols;
> + uint64_t total = 0;
> +
> + for (options::String_set::const_iterator
> + it = parameters->options().wrap_begin();
> + it != parameters->options().wrap_end(); ++it) {
> + total++;
> + wrapped_symbols.push_back(it->c_str());
> + }
>
> total is redundant -- just use wrapped_symbols.size().
>
> Furthermore, if you add an extra member function to DEFINE_set that
> exposes the String_set::size() method, e.g.:
>
> options::String_set::size_type
> varname__##_size() const
> { return this->varname__##_.value.size(); }
>
> ... you could avoid copying to and from the intermediate vector.
>
> (I *think* all of the various alternative implementations we might use
> for Unordered_set provide a constant-time size() method.)
I have attached the patch with those changes.
* plugin.cc (get_wrap_symbols): New plugin interface.
(load): Add get_wrap_symbols to transfer vector.
* plugin-api.h (ld_plugin_get_wrap_symbols): New plugin interface.
* options.h (options::String_set::size_type): New macro function.
* testsuite/plugin_test.c (onload): Call and check get_wrap_symbols
interface.
* testsuite/plugin_test_wrap_symbols.sh: New test script.
* testsuite/plugin_test_wrap_symbols_1.cc: New file.
* testsuite/plugin_test_wrap_symbols_2.cc: New file.
* testsuite/Makefile.am (plugin_test_wrap_symbols): New test.
* testsuite/Makefile.in: Regenerate.
Thanks
Sri
>
> -cary
-------------- next part --------------
2017-11-21 Sriraman Tallam <tmsriram@google.com>
* plugin.cc (get_wrap_symbols): New plugin interface.
(load): Add get_wrap_symbols to transfer vector.
* plugin-api.h (ld_plugin_get_wrap_symbols): New plugin interface.
* options.h (options::String_set::size_type): New macro function.
* testsuite/plugin_test.c (onload): Call and check get_wrap_symbols
interface.
* testsuite/plugin_test_wrap_symbols.sh: New test script.
* testsuite/plugin_test_wrap_symbols_1.cc: New file.
* testsuite/plugin_test_wrap_symbols_2.cc: New file.
* testsuite/Makefile.am (plugin_test_wrap_symbols): New test.
* testsuite/Makefile.in: Regenerate.
diff --git a/gold/options.h b/gold/options.h
index 2a43e8d4e0..b726f746b2 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -471,7 +471,11 @@ struct Struct_special : public Struct_var
\
options::String_set::const_iterator \
varname__##_end() const \
- { return this->varname__##_.value.end(); }
+ { return this->varname__##_.value.end(); } \
+ \
+ options::String_set::size_type \
+ varname__##_size() const \
+ { return this->varname__##_.value.size(); } \
// When you have a list of possible values (expressed as string)
// After helparg__ should come an initializer list, like
diff --git a/gold/plugin.cc b/gold/plugin.cc
index 5ea23b5bdd..f1c32ecaf5 100644
--- a/gold/plugin.cc
+++ b/gold/plugin.cc
@@ -167,6 +167,9 @@ static enum ld_plugin_status
get_input_section_size(const struct ld_plugin_section section,
uint64_t* secsize);
+static enum ld_plugin_status
+get_wrap_symbols(uint64_t *num_symbols, const char ***wrap_symbol_list);
+
};
#endif // ENABLE_PLUGINS
@@ -211,7 +214,7 @@ Plugin::load()
sscanf(ver, "%d.%d", &major, &minor);
// Allocate and populate a transfer vector.
- const int tv_fixed_size = 29;
+ const int tv_fixed_size = 30;
int tv_size = this->args_.size() + tv_fixed_size;
ld_plugin_tv* tv = new ld_plugin_tv[tv_size];
@@ -345,6 +348,10 @@ Plugin::load()
tv[i].tv_tag = LDPT_GET_INPUT_SECTION_SIZE;
tv[i].tv_u.tv_get_input_section_size = get_input_section_size;
+ ++i;
+ tv[i].tv_tag = LDPT_GET_WRAP_SYMBOLS;
+ tv[i].tv_u.tv_get_wrap_symbols = get_wrap_symbols;
+
++i;
tv[i].tv_tag = LDPT_NULL;
tv[i].tv_u.tv_val = 0;
@@ -1797,6 +1804,25 @@ get_input_section_size(const struct ld_plugin_section section,
return LDPS_OK;
}
+static enum ld_plugin_status
+get_wrap_symbols(uint64_t *count, const char ***wrap_symbols)
+{
+ gold_assert(parameters->options().has_plugins());
+ *count = parameters->options().wrap_size();
+
+ if (*count == 0)
+ return LDPS_OK;
+
+ *wrap_symbols = new const char *[*count];
+ int i = 0;
+ for (options::String_set::const_iterator
+ it = parameters->options().wrap_begin();
+ it != parameters->options().wrap_end(); ++it, ++i) {
+ (*wrap_symbols)[i] = it->c_str();
+ }
+ return LDPS_OK;
+}
+
// Specify the ordering of sections in the final layout. The sections are
// specified as (handle,shndx) pairs in the two arrays in the order in
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index d8426db62f..802cf4446f 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -2318,6 +2318,19 @@ plugin_test_12: export_dynamic_plugin.o gcctestdir/ld plugin_test.so export_dyna
plugin_test_12.err: plugin_test_12
@touch plugin_test_12.err
+check_PROGRAMS += plugin_test_wrap_symbols
+check_SCRIPTS += plugin_test_wrap_symbols.sh
+check_DATA += plugin_test_wrap_symbols.err
+MOSTLYCLEANFILES += plugin_test_wrap_symbols.err
+plugin_test_wrap_symbols_1.o: plugin_test_wrap_symbols_1.cc
+ $(COMPILE) -c -o $@ $<
+plugin_test_wrap_symbols_2.o: plugin_test_wrap_symbols_2.cc
+ $(COMPILE) -c -o $@ $<
+plugin_test_wrap_symbols: plugin_test_wrap_symbols_1.o plugin_test_wrap_symbols_2.o gcctestdir/ld plugin_test.so
+ $(CXXLINK) -Bgcctestdir/ -Wl,--plugin,"./plugin_test.so" -Wl,--wrap=hello,--wrap=jello plugin_test_wrap_symbols_1.o plugin_test_wrap_symbols_2.o 2>plugin_test_wrap_symbols.err
+plugin_test_wrap_symbols.err: plugin_test_wrap_symbols
+ @touch plugin_test_wrap_symbols.err
+
check_PROGRAMS += plugin_test_start_lib
check_SCRIPTS += plugin_test_start_lib.sh
check_DATA += plugin_test_start_lib.err
diff --git a/gold/testsuite/plugin_test.c b/gold/testsuite/plugin_test.c
index e8c8a5dfcf..fbd32977ef 100644
--- a/gold/testsuite/plugin_test.c
+++ b/gold/testsuite/plugin_test.c
@@ -68,6 +68,7 @@ static ld_plugin_get_input_section_name get_input_section_name = NULL;
static ld_plugin_get_input_section_contents get_input_section_contents = NULL;
static ld_plugin_update_section_order update_section_order = NULL;
static ld_plugin_allow_section_ordering allow_section_ordering = NULL;
+static ld_plugin_get_wrap_symbols get_wrap_symbols = NULL;
#define MAXOPTS 10
@@ -158,6 +159,9 @@ onload(struct ld_plugin_tv *tv)
case LDPT_ALLOW_SECTION_ORDERING:
allow_section_ordering = *entry->tv_u.tv_allow_section_ordering;
break;
+ case LDPT_GET_WRAP_SYMBOLS:
+ get_wrap_symbols = *entry->tv_u.tv_get_wrap_symbols;
+ break;
default:
break;
}
@@ -247,6 +251,28 @@ onload(struct ld_plugin_tv *tv)
return LDPS_ERR;
}
+ if (get_wrap_symbols == NULL)
+ {
+ fprintf(stderr, "tv_get_wrap_symbols interface missing\n");
+ return LDPS_ERR;
+ }
+ else
+ {
+ const char **wrap_symbols;
+ uint64_t count = 0;
+ if (get_wrap_symbols(&count, &wrap_symbols) == LDPS_OK)
+ {
+ (*message)(LDPL_INFO, "Number of wrap symbols = %lu", count);
+ for (; count > 0; --count)
+ (*message)(LDPL_INFO, "Wrap symbol %s", wrap_symbols[count - 1]);
+ }
+ else
+ {
+ fprintf(stderr, "tv_get_wrap_symbols interface call failed\n");
+ return LDPS_ERR;
+ }
+ }
+
return LDPS_OK;
}
diff --git a/gold/testsuite/plugin_test_wrap_symbols.sh b/gold/testsuite/plugin_test_wrap_symbols.sh
index e69de29bb2..2133bf0a82 100755
--- a/gold/testsuite/plugin_test_wrap_symbols.sh
+++ b/gold/testsuite/plugin_test_wrap_symbols.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+
+# plugin_test_wrap_symbols.sh -- a test case for the plugin API.
+
+# Copyright (C) 2017 onwards Free Software Foundation, Inc.
+# Written by Teresa Johnson <tejohnson@google.com>.
+
+# This file is part of gold.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+
+# This file goes with plugin_test.c, a simple plug-in library that
+# exercises the basic interfaces and prints out version numbers and
+# options passed to the plugin.
+
+# This checks if the get_wrap_symbols plugin interface works as
+# expected.
+
+check()
+{
+ if ! grep -q "$2" "$1"
+ then
+ echo "Did not find expected output in $1:"
+ echo " $2"
+ echo ""
+ echo "Actual output below:"
+ cat "$1"
+ exit 1
+ fi
+}
+
+check plugin_test_wrap_symbols.err "API version:"
+check plugin_test_wrap_symbols.err "gold version:"
+check plugin_test_wrap_symbols.err "Number of wrap symbols = 2"
+check plugin_test_wrap_symbols.err "Wrap symbol hello"
+check plugin_test_wrap_symbols.err "Wrap symbol jello"
+check plugin_test_wrap_symbols.err "cleanup hook called"
+
+exit 0
diff --git a/gold/testsuite/plugin_test_wrap_symbols_1.cc b/gold/testsuite/plugin_test_wrap_symbols_1.cc
index e69de29bb2..90587efbb9 100644
--- a/gold/testsuite/plugin_test_wrap_symbols_1.cc
+++ b/gold/testsuite/plugin_test_wrap_symbols_1.cc
@@ -0,0 +1,40 @@
+/* plugin_test_wrap_symbols -- a test case for gold
+
+ Copyright (C) 2017 onwards Free Software Foundation, Inc.
+ Written by Sriraman Tallam <tmsriram@google.com>.
+
+ This file is part of gold.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ MA 02110-1301, USA. */
+
+extern "C" {
+int __real_hello();
+int __wrap_hello()
+{
+ return __real_hello();
+}
+int hello();
+int __real_jello();
+int __wrap_jello()
+{
+ return __real_jello();
+}
+int jello();
+int main()
+{
+ return 0;
+}
+}
diff --git a/gold/testsuite/plugin_test_wrap_symbols_2.cc b/gold/testsuite/plugin_test_wrap_symbols_2.cc
index e69de29bb2..902cc3c076 100644
--- a/gold/testsuite/plugin_test_wrap_symbols_2.cc
+++ b/gold/testsuite/plugin_test_wrap_symbols_2.cc
@@ -0,0 +1,33 @@
+/* plugin_test_wrap_symbols -- a test case for gold
+
+ Copyright (C) 2017 onwards Free Software Foundation, Inc.
+ Written by Sriraman Tallam <tmsriram@google.com>.
+
+ This file is part of gold.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ MA 02110-1301, USA. */
+
+extern "C" {
+int hello()
+{
+ return 0;
+}
+
+int jello()
+{
+ return 0;
+}
+}
diff --git a/include/plugin-api.h b/include/plugin-api.h
index 3a3e8b456d..901369ad4d 100644
--- a/include/plugin-api.h
+++ b/include/plugin-api.h
@@ -365,6 +365,11 @@ enum ld_plugin_status
(*ld_plugin_get_input_section_size) (const struct ld_plugin_section section,
uint64_t *secsize);
+typedef
+enum ld_plugin_status
+(*ld_plugin_get_wrap_symbols) (uint64_t *num_symbols,
+ const char ***wrap_symbol_list);
+
enum ld_plugin_level
{
LDPL_INFO,
@@ -407,7 +412,8 @@ enum ld_plugin_tag
LDPT_UNIQUE_SEGMENT_FOR_SECTIONS = 27,
LDPT_GET_SYMBOLS_V3 = 28,
LDPT_GET_INPUT_SECTION_ALIGNMENT = 29,
- LDPT_GET_INPUT_SECTION_SIZE = 30
+ LDPT_GET_INPUT_SECTION_SIZE = 30,
+ LDPT_GET_WRAP_SYMBOLS = 31
};
/* The plugin transfer vector. */
@@ -441,6 +447,7 @@ struct ld_plugin_tv
ld_plugin_unique_segment_for_sections tv_unique_segment_for_sections;
ld_plugin_get_input_section_alignment tv_get_input_section_alignment;
ld_plugin_get_input_section_size tv_get_input_section_size;
+ ld_plugin_get_wrap_symbols tv_get_wrap_symbols;
} tv_u;
};
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