libdrgn: build with bundled elfutils

Now that we have the bundled version of elfutils, build it from libdrgn
and link to it. We can also get rid of the elfutils version checks from
the libdrgn code.

Author: osandov

.travis.yml

@@ -10,13 +10,10 @@ script: python setup.py test
 env:
   global:
     - OMP_NUM_THREADS=4
-  matrix:
-    - CC=gcc
-    - CC=clang
 
 addons:
   apt:
     packages:
-      - libelf-dev
-      - libdw-dev
-      - libomp-dev
+      - libbz2-dev
+      - liblzma-dev
+      - zlib1g-dev

README.rst

@@ -42,17 +42,33 @@ Documentation can be found at `drgn.readthedocs.io
 Installation
 ------------
 
-Install the following dependencies:
+.. start-install-dependencies
 
-* Python 3.6 or newer
-* elfutils development libraries (libelf and libdw)
-* GNU autotools (autoconf, automake, and libtool) and pkgconf
+Install dependencies:
+
+Arch Linux::
+
+    $ sudo pacman -S --needed autoconf automake bison bzip2 flex gawk gcc libtool make pkgconf python python-setuptools xz zlib
+
+Debian/Ubuntu::
+
+    $ sudo apt-get install autoconf automake bison flex gawk gcc libbz2-dev liblzma-dev libtool make pkgconf python3 python3-dev python3-setuptools zlib1g-dev
+
+Note that Debian Stretch, Ubuntu Trusty, and Ubuntu Xenial (and older) ship
+Python versions which are too old. Python 3.6 or newer must be installed
+manually.
+
+Fedora::
+
+    $ sudo dnf install autoconf automake bison bzip2-devel flex gawk gcc libtool make pkgconf python3 python3-devel python3-setuptools xz-devel zlib-devel
 
 Optionally, install:
 
 * `libkdumpfile <https://github.com/ptesarik/libkdumpfile>`_ if you want
   support for kdump-compressed kernel core dumps
 
+.. end-install-dependencies
+
 Then, run:
 
 .. code-block:: console

docs/installation.rst

@@ -3,37 +3,32 @@ Installation
 
 .. highlight:: console
 
-drgn depends on `Python <https://www.python.org/>`_ 3.6 or newer as well as
-`elfutils <https://sourceware.org/elfutils/>`_. The build requires `GCC
-<https://gcc.gnu.org/>`_ or `Clang <https://clang.llvm.org/>`_, `GNU Make
-<https://www.gnu.org/software/make/>`_, `pkgconf <http://pkgconf.org/>`_, and
-`setuptools <https://pypi.org/project/setuptools/>`_. A build from a Git
-checkout also requires the GNU Autotools (`autoconf
-<https://www.gnu.org/software/autoconf/>`_, `automake
-<https://www.gnu.org/software/automake/automake.html>`_, and `libtool
-<https://www.gnu.org/software/libtool/libtool.html>`_). Install those
-dependencies:
-
-Arch Linux::
-
-    $ sudo pacman -S --needed autoconf automake libtool make gcc pkgconf libelf python python-setuptools
-
-Debian/Ubuntu::
-
-    $ sudo apt-get install autoconf automake libtool make gcc pkgconf libelf-dev libdw-dev python3 python3-dev python3-setuptools
-
-Note that Debian, Ubuntu Trusty, and Ubuntu Xenial ship Python versions which
-are too old, so a newer version must be installed manually.
-
-Due to a packaging `bug
-<https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=885071>`_, the following may
-also be required::
-
-    $ sudo apt-get install liblzma-dev zlib1g-dev
-
-Fedora::
-
-    $ sudo dnf install autoconf automake libtool make gcc pkgconf elfutils-devel python3 python3-devel python3-setuptools
+drgn depends on:
+
+- `Python <https://www.python.org/>`_ 3.6 or newer
+- `zlib <https://www.zlib.net>`_
+- `xz <https://tukaani.org/xz/>`_
+- `bzip2 <http://www.bzip.org>`_
+
+A version of `elfutils <https://sourceware.org/elfutils/>`_ is bundled with
+drgn.
+
+The build requires:
+
+- `GCC <https://gcc.gnu.org/>`_
+- `GNU Make <https://www.gnu.org/software/make/>`_
+- `pkgconf <http://pkgconf.org/>`_
+- `setuptools <https://pypi.org/project/setuptools/>`_
+- `autoconf <https://www.gnu.org/software/autoconf/>`_
+- `automake <https://www.gnu.org/software/automake/>`_
+- `libtool <https://www.gnu.org/software/libtool/>`_
+- `flex <https://github.com/westes/flex>`_
+- `GNU bison <https://www.gnu.org/software/bison/>`_
+- `GNU awk <https://www.gnu.org/software/gawk/>`_
+
+.. include:: ../README.rst
+    :start-after: start-install-dependencies
+    :end-before: end-install-dependencies
 
 Then, drgn can be built and installed::
 

libdrgn/Makefile.am

@@ -1,5 +1,9 @@
 ACLOCAL_AMFLAGS = -I m4
 
+SUBDIRS = elfutils include
+
+AM_CPPFLAGS = -Iinclude -D_GNU_SOURCE
+
 include_HEADERS = drgn.h
 
 noinst_LTLIBRARIES = libdrgnimpl.la
@@ -51,22 +55,21 @@ libdrgnimpl_la_SOURCES = arch_x86_64.c \
 			 vector.c \
 			 vector.h
 
-libdrgnimpl_la_CFLAGS = -fvisibility=hidden -fopenmp $(libelf_CFLAGS) \
-			$(libdw_CFLAGS)
-libdrgnimpl_la_CPPFLAGS = -D_GNU_SOURCE
-libdrgnimpl_la_LIBADD = $(libelf_LIBS) $(libdw_LIBS)
+libdrgnimpl_la_CFLAGS = -fvisibility=hidden -fopenmp
 
 if WITH_LIBKDUMPFILE
 libdrgnimpl_la_SOURCES += kdump.c
 libdrgnimpl_la_CFLAGS += $(libkdumpfile_CFLAGS)
-libdrgnimpl_la_LIBADD += $(libkdumpfile_LIBS)
+libdrgnimpl_la_LIBADD = $(libkdumpfile_LIBS)
 endif
 
+elfutils_LIBS = elfutils/libdw/libdw.a elfutils/libelf/libelf.a -lz -llzma -lbz2
+
 lib_LTLIBRARIES = libdrgn.la
 
 libdrgn_la_SOURCES =
 libdrgn_la_LDFLAGS = -version-info 0:0:0
-libdrgn_la_LIBADD = libdrgnimpl.la
+libdrgn_la_LIBADD = libdrgnimpl.la $(elfutils_LIBS)
 
 if WITH_PYTHON
 noinst_LTLIBRARIES += _drgn.la
@@ -90,10 +93,10 @@ _drgn_la_SOURCES = python/docstrings.h \
 nodist__drgn_la_SOURCES = python/constants.c python/docstrings.c
 
 _drgn_la_CFLAGS = -fvisibility=hidden
-_drgn_la_CPPFLAGS = $(PYTHON_CPPFLAGS) -D_GNU_SOURCE
+_drgn_la_CPPFLAGS = $(AM_CPPFLAGS) $(PYTHON_CPPFLAGS)
 _drgn_la_LDFLAGS = -Wl,--exclude-libs,ALL -avoid-version -module -shared \
 		   -rpath $(pkgpyexecdir)
-_drgn_la_LIBADD = libdrgnimpl.la
+_drgn_la_LIBADD = libdrgnimpl.la $(elfutils_LIBS)
 
 if WITH_LIBKDUMPFILE
 _drgn_la_CFLAGS += $(libkdumpfile_CFLAGS)

libdrgn/configure.ac

@@ -48,6 +48,7 @@ python3-devel or python3-dev) or specify the location of the Python development
 headers by setting the PYTHON_CPPFLAGS environment variable.])])
 	    CPPFLAGS="$save_CPPFLAGS"])
 
+PKG_PROG_PKG_CONFIG
 AC_ARG_WITH([libkdumpfile],
 	    [AS_HELP_STRING([--with-libkdumpfile],
 			    [build with support for the makedumpfile kernel
@@ -62,14 +63,13 @@ AS_CASE(["x$with_libkdumpfile"],
 AM_CONDITIONAL([WITH_LIBKDUMPFILE], [test "x$with_libkdumpfile" = xyes])
 AM_COND_IF([WITH_LIBKDUMPFILE], [AC_DEFINE(WITH_LIBKDUMPFILE)])
 
-PKG_PROG_PKG_CONFIG
-PKG_CHECK_MODULES(libelf, [libelf])
-AC_SUBST([libelf_CFLAGS])
-AC_SUBST([libelf_LIBS])
-dnl We need dwarf_cu_getdwarf() which was added in elfutils 0.160.
-PKG_CHECK_MODULES(libdw, [libdw >= 0.160])
-AC_SUBST([libdw_CFLAGS])
-AC_SUBST([libdw_LIBS])
+AX_SUBDIRS_CONFIGURE([elfutils],
+		     [[--enable-maintainer-mode],
+		      [--disable-nls],
+		      [--disable-programs],
+		      [--disable-shared]],
+		     [CFLAGS=-fPIC -Wno-error], [],
+		     [--disable-static])
 
-AC_CONFIG_FILES([Makefile])
+AC_CONFIG_FILES([Makefile include/Makefile])
 AC_OUTPUT

libdrgn/dwarf_index.c

@@ -1825,20 +1825,9 @@ static int drgn_dwfl_module_removed(Dwfl_Module *module, void *userdatap,
 
 static void drgn_remove_dwfl_modules(Dwfl *dwfl, bool unindexed)
 {
-	int fd;
-
-	/*
-	 * Work around a libdwfl bug that causes it to close stdin when it frees
-	 * some modules which are reported by dwfl_core_file_report().
-	 */
-	fd = dup(0);
 	dwfl_report_begin(dwfl);
 	dwfl_report_end(dwfl, drgn_dwfl_module_removed,
 			unindexed ? dwfl : NULL);
-	if (fd != -1) {
-		dup2(fd, 0);
-		close(fd);
-	}
 }
 
 void drgn_remove_unindexed_dwfl_modules(Dwfl *dwfl)

libdrgn/dwarf_info_cache.c

@@ -14,13 +14,6 @@
 #include "type_index.h"
 #include "vector.h"
 
-#if !_ELFUTILS_PREREQ(0, 162)
-#define DW_TAG_atomic_type 0x47
-#endif
-#if !_ELFUTILS_PREREQ(0, 171)
-#define DW_FORM_implicit_const 0x21
-#endif
-
 DEFINE_HASH_TABLE_FUNCTIONS(dwarf_type_map, hash_pair_ptr_type,
 			    hash_table_scalar_eq)
 

libdrgn/include/.gitignore

@@ -0,0 +1,3 @@
+*
+!/.gitignore
+!/Makefile.am

libdrgn/include/Makefile.am

@@ -0,0 +1,31 @@
+# "Install" the elfutils headers to the build directory.
+
+BUILT_SOURCES = dwarf.h \
+		elf.h \
+		elfutils/elf-knowledge.h \
+		elfutils/known-dwarf.h \
+		elfutils/libasm.h \
+		elfutils/libdw.h \
+		elfutils/libdwelf.h \
+		elfutils/libdwfl.h \
+		elfutils/version.h \
+		gelf.h \
+		libelf.h \
+		nlist.h
+
+dwarf.h: ../elfutils/libdw/dwarf.h
+elf.h: ../elfutils/libelf/elf.h
+elfutils/elf-knowledge.h: ../elfutils/libelf/elf-knowledge.h
+elfutils/known-dwarf.h: ../elfutils/libdw/known-dwarf.h
+elfutils/libasm.h: ../elfutils/libasm/libasm.h
+elfutils/libdw.h: ../elfutils/libdw/libdw.h
+elfutils/libdwelf.h: ../elfutils/libdwelf/libdwelf.h
+elfutils/libdwfl.h: ../elfutils/libdwfl/libdwfl.h
+elfutils/version.h: ../elfutils/version.h
+gelf.h: ../elfutils/libelf/gelf.h
+libelf.h: ../elfutils/libelf/libelf.h
+nlist.h: ../elfutils/libelf/nlist.h
+
+$(BUILT_SOURCES):
+	mkdir -p $$(dirname $@)
+	cp $< $@

libdrgn/internal.c

@@ -43,13 +43,8 @@ struct drgn_error *read_elf_section(Elf_Scn *scn, Elf_Data **ret)
 	if (!shdr)
 		return drgn_error_libelf();
 	if (shdr->sh_flags & SHF_COMPRESSED) {
-#if _ELFUTILS_PREREQ(0, 165)
 		if (elf_compress(scn, 0, 0) < 0)
 			return drgn_error_libelf();
-#else
-		return drgn_error_create(DRGN_ERROR_ELF_FORMAT,
-					 "section is compressed but libelf does not support decompression");
-#endif
 	}
 	data = elf_getdata(scn, NULL);
 	if (!data)

libdrgn/m4/.gitignore

@@ -1,2 +1,3 @@
 *
 !/.gitignore
+!/ax_subdirs_configure.m4