From 62ce266b0b261def2c6329be9814ffdcc11964d6 Mon Sep 17 00:00:00 2001 From: Martin Galvan Date: Fri, 8 Jul 2016 20:01:55 +0530 Subject: Add pretty printers for the NPTL lock types This patch adds pretty printers for the following NPTL types: - pthread_mutex_t - pthread_mutexattr_t - pthread_cond_t - pthread_condattr_t - pthread_rwlock_t - pthread_rwlockattr_t To load the pretty printers into your gdb session, do the following: python import sys sys.path.insert(0, '/path/to/glibc/build/nptl/pretty-printers') end source /path/to/glibc/source/pretty-printers/nptl-printers.py You can check which printers are registered and enabled by issuing the 'info pretty-printer' gdb command. Printers should trigger automatically when trying to print a variable of one of the types mentioned above. The printers are architecture-independent, and were manually tested on both the gdb CLI and Eclipse CDT. In order to work, the printers need to know the values of various flags that are scattered throughout pthread.h and pthreadP.h as enums and #defines. Since replicating these constants in the printers file itself would create a maintenance burden, I wrote a script called gen-py-const.awk that Makerules uses to extract the constants. This script is pretty much the same as gen-as-const.awk, except it doesn't cast the constant values to 'long' and is thorougly documented. The constants need only to be enumerated in a .pysym file, which is then referenced by a Make variable called gen-py-const-headers. As for the install directory, I discussed this with Mike Frysinger and Siddhesh Poyarekar, and we agreed that it can be handled in a separate patch, and it shouldn't block merging of this one. In addition, I've written a series of test cases for the pretty printers. Each lock type (mutex, condvar and rwlock) has two test programs, one for itself and other for its related 'attributes' object. Each test program in turn has a PExpect-based Python script that drives gdb and compares its output to the expected printer's. The tests run on the glibc host, which is assumed to have both gdb and PExpect; if either is absent the tests will fail with code 77 (UNSUPPORTED). For cross-testing you should use cross-test-ssh.sh as test-wrapper. I've tested the printers on both a native build and a cross build using a Beaglebone Black, with the build system's filesystem shared with the board through NFS. Finally, I've written a README that explains all this and more. Hopefully this should be good to go in now. Thanks. ChangeLog: 2016-07-04 Martin Galvan * Makeconfig (build-hardcoded-path-in-tests): Set to 'yes' for shared builds if tests-need-hardcoded-path is defined. (all-subdirs): Add pretty-printers. * Makerules ($(py-const)): New rule. * Rules (others): Add $(py-const), if defined. * nptl/Makefile (gen-py-const-headers): Define. * nptl/nptl-printers.py: New file. * nptl/nptl_lock_constants.pysym: Likewise. * pretty-printers/Makefile: Likewise. * pretty-printers/README: Likewise. * pretty-printers/test-condvar-attributes.c: Likewise. * pretty-printers/test-condvar-attributes.p: Likewise. * pretty-printers/test-condvar-printer.c: Likewise. * pretty-printers/test-condvar-printer.py: Likewise. * pretty-printers/test-mutex-attributes.c: Likewise. * pretty-printers/test-mutex-attributes.py: Likewise. * pretty-printers/test-mutex-printer.c: Likewise. * pretty-printers/test-mutex-printer.py: Likewise. * pretty-printers/test-rwlock-attributes.c: Likewise. * pretty-printers/test-rwlock-attributes.py: Likewise. * pretty-printers/test-rwlock-printer.c: Likewise. * pretty-printers/test-rwlock-printer.py: Likewise. * pretty-printers/test_common.py: Likewise. * scripts/gen-py-const.awk: Likewise. --- scripts/gen-py-const.awk | 118 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 scripts/gen-py-const.awk (limited to 'scripts') diff --git a/scripts/gen-py-const.awk b/scripts/gen-py-const.awk new file mode 100644 index 0000000000..4586f59d89 --- /dev/null +++ b/scripts/gen-py-const.awk @@ -0,0 +1,118 @@ +# Script to generate constants for Python pretty printers. +# +# Copyright (C) 2016 Free Software Foundation, Inc. +# This file is part of the GNU C Library. +# +# The GNU C Library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# The GNU C Library 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 +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with the GNU C Library; if not, see +# . + +# This script is a smaller version of the clever gen-asm-const.awk hack used to +# generate ASM constants from .sym files. We'll use this to generate constants +# for Python pretty printers. +# +# The input to this script are .pysym files that look like: +# #C_Preprocessor_Directive... +# NAME1 +# NAME2 expression... +# +# A line giving just a name implies an expression consisting of just that name. +# Comments start with '--'. +# +# The output of this script is a 'dummy' function containing 'asm' declarations +# for each non-preprocessor line in the .pysym file. The expression values +# will appear as input operands to the 'asm' declaration. For example, if we +# have: +# +# /* header.h */ +# #define MACRO 42 +# +# struct S { +# char c1; +# char c2; +# char c3; +# }; +# +# enum E { +# ZERO, +# ONE +# }; +# +# /* symbols.pysym */ +# #include +# #include "header.h" +# -- This is a comment +# MACRO +# C3_OFFSET offsetof(struct S, c3) +# E_ONE ONE +# +# the output will be: +# +# #include +# #include "header.h" +# void dummy(void) +# { +# asm ("@name@MACRO@value@%0@" : : "i" (MACRO)); +# asm ("@name@C3_OFFSET@value@%0@" : : "i" (offsetof(struct S, c3))); +# asm ("@name@E_ONE@value@%0@" : : "i" (ONE)); +# } +# +# We'll later feed this output to gcc -S. Since '-S' tells gcc to compile but +# not assemble, gcc will output something like: +# +# dummy: +# ... +# @name@MACRO@value@$42@ +# @name@C3_OFFSET@value@$2@ +# @name@E_ONE@value@$1@ +# +# Finally, we can process that output to extract the constant values. +# Notice gcc may prepend a special character such as '$' to each value. + +# found_symbol indicates whether we found a non-comment, non-preprocessor line. +BEGIN { found_symbol = 0 } + +# C preprocessor directives go straight through. +/^#/ { print; next; } + +# Skip comments. +/--/ { next; } + +# Trim leading whitespace. +{ sub(/^[[:blank:]]*/, ""); } + +# If we found a non-comment, non-preprocessor line, print the 'dummy' function +# header. +NF > 0 && !found_symbol { + print "void dummy(void)\n{"; + found_symbol = 1; +} + +# If the line contains just a name, duplicate it so we can use that name +# as the value of the expression. +NF == 1 { sub(/^.*$/, "& &"); } + +# If a line contains a name and an expression... +NF > 1 { + name = $1; + + # Remove any characters before the second field. + sub(/^[^[:blank:]]+[[:blank:]]+/, ""); + + # '$0' ends up being everything that appeared after the first field + # separator. + printf " asm (\"@name@%s@value@%0@\" : : \"i\" (%s));\n", name, $0; +} + +# Close the 'dummy' function. +END { if (found_symbol) print "}"; } -- cgit v1.2.1