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bug#19973: [PATCH 2/2] grafts: Add (guix build debug-link) and use it.
|
From: |
Ludovic Courtès |
|
Subject: |
bug#19973: [PATCH 2/2] grafts: Add (guix build debug-link) and use it. |
|
Date: |
Tue, 21 Aug 2018 22:56:39 +0200 |
Fixes <https://bugs.gnu.org/19973>.
Reported by Mark H Weaver <address@hidden>.
* guix/build/debug-link.scm: New file.
* guix/build/graft.scm (%graft-hooks): New variable.
(graft): Add #:hooks and honor it.
* guix/grafts.scm (graft-derivation/shallow): Add (guix build
debug-link) and (guix elf) to #:modules.
* tests/debug-link.scm: New file.
* Makefile.am (MODULES): Add guix/build/debug-link.scm.
(SCM_TESTS): Add tests/debug-link.scm.
---
Makefile.am | 2 +
guix/build/debug-link.scm | 210 ++++++++++++++++++++++++++++++++++++++
guix/build/graft.scm | 14 ++-
guix/grafts.scm | 4 +-
tests/debug-link.scm | 154 ++++++++++++++++++++++++++++
5 files changed, 381 insertions(+), 3 deletions(-)
create mode 100644 guix/build/debug-link.scm
create mode 100644 tests/debug-link.scm
diff --git a/Makefile.am b/Makefile.am
index bdf1c63ce..324674a60 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -171,6 +171,7 @@ MODULES = \
guix/build/svn.scm \
guix/build/syscalls.scm \
guix/build/gremlin.scm \
+ guix/build/debug-link.scm \
guix/build/emacs-utils.scm \
guix/build/java-utils.scm \
guix/build/lisp-utils.scm \
@@ -363,6 +364,7 @@ SCM_TESTS = \
tests/syscalls.scm \
tests/inferior.scm \
tests/gremlin.scm \
+ tests/debug-link.scm \
tests/bournish.scm \
tests/lint.scm \
tests/publish.scm \
diff --git a/guix/build/debug-link.scm b/guix/build/debug-link.scm
new file mode 100644
index 000000000..9167737fb
--- /dev/null
+++ b/guix/build/debug-link.scm
@@ -0,0 +1,210 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 Ludovic Courtès <address@hidden>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; GNU Guix 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 GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build debug-link)
+ #:use-module (guix elf)
+ #:use-module ((guix build utils)
+ #:select (find-files elf-file? make-file-writable))
+ #:use-module (rnrs bytevectors)
+ #:use-module (rnrs io ports)
+ #:use-module (srfi srfi-1)
+ #:use-module (system foreign)
+ #:use-module (ice-9 match)
+ #:export (debuglink-crc32
+ elf-debuglink
+ set-debuglink-crc
+
+ graft-debug-links))
+
+;;; Commentary:
+;;;
+;;; This module provides tools to deal with '.gnu_debuglink' sections in ELF
+;;; files. These sections are created by 'objcopy --add-gnu-debuglink' to
+;;; create separate debug files (info "(gdb) Separate Debug Files").
+;;;
+;;; The main facility of this module is 'graft-debug-links', which allows us
+;;; to update the CRC that appears in '.gnu_debuglink' sections when grafting,
+;;; such that separate debug files remain usable after grafting. Failing to
+;;; do that, GDB would complain about CRC mismatch---see
+;;; <https://bugs.gnu.org/19973>.
+;;;
+;;; Code:
+
+(define %crc32-table
+ ;; CRC table taken from "(gdb) Separate Debug Files".
+ ;; TODO: Wouldn't it be nice to generate it "from source" with a macro?
+ #(#x00000000 #x77073096 #xee0e612c #x990951ba #x076dc419
+ #x706af48f #xe963a535 #x9e6495a3 #x0edb8832 #x79dcb8a4
+ #xe0d5e91e #x97d2d988 #x09b64c2b #x7eb17cbd #xe7b82d07
+ #x90bf1d91 #x1db71064 #x6ab020f2 #xf3b97148 #x84be41de
+ #x1adad47d #x6ddde4eb #xf4d4b551 #x83d385c7 #x136c9856
+ #x646ba8c0 #xfd62f97a #x8a65c9ec #x14015c4f #x63066cd9
+ #xfa0f3d63 #x8d080df5 #x3b6e20c8 #x4c69105e #xd56041e4
+ #xa2677172 #x3c03e4d1 #x4b04d447 #xd20d85fd #xa50ab56b
+ #x35b5a8fa #x42b2986c #xdbbbc9d6 #xacbcf940 #x32d86ce3
+ #x45df5c75 #xdcd60dcf #xabd13d59 #x26d930ac #x51de003a
+ #xc8d75180 #xbfd06116 #x21b4f4b5 #x56b3c423 #xcfba9599
+ #xb8bda50f #x2802b89e #x5f058808 #xc60cd9b2 #xb10be924
+ #x2f6f7c87 #x58684c11 #xc1611dab #xb6662d3d #x76dc4190
+ #x01db7106 #x98d220bc #xefd5102a #x71b18589 #x06b6b51f
+ #x9fbfe4a5 #xe8b8d433 #x7807c9a2 #x0f00f934 #x9609a88e
+ #xe10e9818 #x7f6a0dbb #x086d3d2d #x91646c97 #xe6635c01
+ #x6b6b51f4 #x1c6c6162 #x856530d8 #xf262004e #x6c0695ed
+ #x1b01a57b #x8208f4c1 #xf50fc457 #x65b0d9c6 #x12b7e950
+ #x8bbeb8ea #xfcb9887c #x62dd1ddf #x15da2d49 #x8cd37cf3
+ #xfbd44c65 #x4db26158 #x3ab551ce #xa3bc0074 #xd4bb30e2
+ #x4adfa541 #x3dd895d7 #xa4d1c46d #xd3d6f4fb #x4369e96a
+ #x346ed9fc #xad678846 #xda60b8d0 #x44042d73 #x33031de5
+ #xaa0a4c5f #xdd0d7cc9 #x5005713c #x270241aa #xbe0b1010
+ #xc90c2086 #x5768b525 #x206f85b3 #xb966d409 #xce61e49f
+ #x5edef90e #x29d9c998 #xb0d09822 #xc7d7a8b4 #x59b33d17
+ #x2eb40d81 #xb7bd5c3b #xc0ba6cad #xedb88320 #x9abfb3b6
+ #x03b6e20c #x74b1d29a #xead54739 #x9dd277af #x04db2615
+ #x73dc1683 #xe3630b12 #x94643b84 #x0d6d6a3e #x7a6a5aa8
+ #xe40ecf0b #x9309ff9d #x0a00ae27 #x7d079eb1 #xf00f9344
+ #x8708a3d2 #x1e01f268 #x6906c2fe #xf762575d #x806567cb
+ #x196c3671 #x6e6b06e7 #xfed41b76 #x89d32be0 #x10da7a5a
+ #x67dd4acc #xf9b9df6f #x8ebeeff9 #x17b7be43 #x60b08ed5
+ #xd6d6a3e8 #xa1d1937e #x38d8c2c4 #x4fdff252 #xd1bb67f1
+ #xa6bc5767 #x3fb506dd #x48b2364b #xd80d2bda #xaf0a1b4c
+ #x36034af6 #x41047a60 #xdf60efc3 #xa867df55 #x316e8eef
+ #x4669be79 #xcb61b38c #xbc66831a #x256fd2a0 #x5268e236
+ #xcc0c7795 #xbb0b4703 #x220216b9 #x5505262f #xc5ba3bbe
+ #xb2bd0b28 #x2bb45a92 #x5cb36a04 #xc2d7ffa7 #xb5d0cf31
+ #x2cd99e8b #x5bdeae1d #x9b64c2b0 #xec63f226 #x756aa39c
+ #x026d930a #x9c0906a9 #xeb0e363f #x72076785 #x05005713
+ #x95bf4a82 #xe2b87a14 #x7bb12bae #x0cb61b38 #x92d28e9b
+ #xe5d5be0d #x7cdcefb7 #x0bdbdf21 #x86d3d2d4 #xf1d4e242
+ #x68ddb3f8 #x1fda836e #x81be16cd #xf6b9265b #x6fb077e1
+ #x18b74777 #x88085ae6 #xff0f6a70 #x66063bca #x11010b5c
+ #x8f659eff #xf862ae69 #x616bffd3 #x166ccf45 #xa00ae278
+ #xd70dd2ee #x4e048354 #x3903b3c2 #xa7672661 #xd06016f7
+ #x4969474d #x3e6e77db #xaed16a4a #xd9d65adc #x40df0b66
+ #x37d83bf0 #xa9bcae53 #xdebb9ec5 #x47b2cf7f #x30b5ffe9
+ #xbdbdf21c #xcabac28a #x53b39330 #x24b4a3a6 #xbad03605
+ #xcdd70693 #x54de5729 #x23d967bf #xb3667a2e #xc4614ab8
+ #x5d681b02 #x2a6f2b94 #xb40bbe37 #xc30c8ea1 #x5a05df1b
+ #x2d02ef8d))
+
+(define (debuglink-crc32 port)
+ "Compute the 32-bit CRC used in in '.gnu_debuglink' over the data read from
+PORT and return it." ;(info "(gdb) Separate Debug Files")
+ (let loop ((crc #xffffffff))
+ (let ((byte (get-u8 port)))
+ (if (eof-object? byte)
+ (logand (lognot crc) #xffffffff)
+ (let* ((index (logand (logxor crc byte) #xff))
+ (lhs (vector-ref %crc32-table index)))
+ (loop (logxor lhs (ash crc -8))))))))
+
+(define (section-contents elf section) ;XXX: copied from linux-modules.scm
+ "Return the contents of SECTION in ELF as a bytevector."
+ (let* ((contents (make-bytevector (elf-section-size section))))
+ (bytevector-copy! (elf-bytes elf) (elf-section-offset section)
+ contents 0
+ (elf-section-size section))
+ contents))
+
+(define null-terminated-bytevector->string
+ (compose pointer->string bytevector->pointer))
+
+(define (elf-debuglink elf)
+ "Return two values: the '.gnu_debuglink' file name of ELF and its CRC.
+Return #f for both if ELF lacks a '.gnu_debuglink' section."
+ (let ((section (elf-section-by-name elf ".gnu_debuglink")))
+ (if section
+ (let ((size (elf-section-size section))
+ (bv (section-contents elf section))
+ (endianness (elf-byte-order elf)))
+ (values (null-terminated-bytevector->string bv)
+ (bytevector-u32-ref bv (- size 4) endianness)))
+ (values #f #f))))
+
+(define (elf-debuglink-crc-offset elf)
+ "Return the offset of the '.gnu_debuglink' 32-bit CRC, or #f if ELF lacks a
+'.gnu_debuglink' section."
+ (let ((section (elf-section-by-name elf ".gnu_debuglink")))
+ (and section
+ (+ (elf-section-offset section)
+ (elf-section-size section)
+ -4))))
+
+(define (set-debuglink-crc file debug-file)
+ "Compute the CRC of DEBUG-FILE and set it as the '.gnu_debuglink' CRC in
+FILE."
+ (let* ((elf (parse-elf (call-with-input-file file get-bytevector-all)))
+ (offset (elf-debuglink-crc-offset elf)))
+ (and offset
+ (let* ((crc (call-with-input-file debug-file debuglink-crc32))
+ (bv (make-bytevector 4)))
+ (bytevector-u32-set! bv 0 crc (elf-byte-order elf))
+ (let ((port (open file O_RDWR)))
+ (set-port-position! port offset)
+ (put-bytevector port bv)
+ (close-port port))))))
+
+
+;;;
+;;; Updating debuglink CRC.
+;;;
+
+(define (find-elf-files outputs)
+ "Return the list of ELF files found in OUTPUTS, a list of top-level store
+directories."
+ (define directories
+ (append-map (lambda (output)
+ (list (string-append output "/bin")
+ (string-append output "/sbin")
+ (string-append output "/lib")
+ (string-append output "/libexec")))
+ outputs))
+
+ (append-map (lambda (directory)
+ (filter elf-file?
+ (with-error-to-port (%make-void-port "w")
+ (lambda ()
+ (find-files directory)))))
+ directories))
+
+(define* (graft-debug-links old-outputs new-outputs mapping
+ #:key (log-port (current-error-port)))
+ "Update the '.gnu_debuglink' CRCs found in ELF files of NEW-OUTPUTS,
+provided NEW-OUTPUTS contains a \"debug\" output, such that those CRCs match
+those of the corresponding '.debug' files found in the \"debug\" output.
+
+This procedure is meant to be used as a \"grafting hook\" by (guix build
+graft)."
+ (match (assoc-ref new-outputs "debug")
+ (#f #t) ;nothing to do
+ (debug-directory
+ (let ((files (find-elf-files (filter-map (match-lambda
+ (("debug" . _)
+ #f)
+ ((name . directory)
+ directory))
+ new-outputs))))
+ (for-each (lambda (file)
+ (let ((debug (string-append debug-directory
+ "/lib/debug" file ".debug")))
+ (when (file-exists? debug)
+ (format log-port
+ "updating '.gnu_debuglink' CRC in '~a'~%"
+ file)
+ (make-file-writable file)
+ (set-debuglink-crc file debug))))
+ files)))))
diff --git a/guix/build/graft.scm b/guix/build/graft.scm
index 8d79e8a50..c119ee71d 100644
--- a/guix/build/graft.scm
+++ b/guix/build/graft.scm
@@ -19,6 +19,7 @@
(define-module (guix build graft)
#:use-module (guix build utils)
+ #:use-module (guix build debug-link)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 vlist)
#:use-module (ice-9 match)
@@ -322,8 +323,13 @@ file name pairs."
#:directories? #t))
(rename-matching-files output mapping))
+(define %graft-hooks
+ ;; Default list of hooks run after grafting.
+ (list graft-debug-links))
+
(define* (graft old-outputs new-outputs mapping
- #:key (log-port (current-output-port)))
+ #:key (log-port (current-output-port))
+ (hooks %graft-hooks))
"Apply the grafts described by MAPPING on OLD-OUTPUTS, leading to
NEW-OUTPUTS. MAPPING must be a list of file name pairs; OLD-OUTPUTS and
NEW-OUTPUTS are lists of output name/file name pairs."
@@ -336,6 +342,10 @@ NEW-OUTPUTS are lists of output name/file name pairs."
files))
(match new-outputs
(((names . files) ...)
- files))))
+ files)))
+ (for-each (lambda (hook)
+ (hook old-outputs new-outputs mapping
+ #:log-port log-port))
+ hooks))
;;; graft.scm ends here
diff --git a/guix/grafts.scm b/guix/grafts.scm
index 4b10b3efd..f303e925f 100644
--- a/guix/grafts.scm
+++ b/guix/grafts.scm
@@ -130,7 +130,9 @@ are not recursively applied to dependencies of DRV."
#:system system
#:guile-for-build guile
#:modules '((guix build graft)
- (guix build utils))
+ (guix build utils)
+ (guix build debug-link)
+ (guix elf))
#:inputs `(,@(map (lambda (out)
`("x" ,drv ,out))
outputs)
diff --git a/tests/debug-link.scm b/tests/debug-link.scm
new file mode 100644
index 000000000..a57f360b2
--- /dev/null
+++ b/tests/debug-link.scm
@@ -0,0 +1,154 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 Ludovic Courtès <address@hidden>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; GNU Guix 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 GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (test-debug-link)
+ #:use-module (guix elf)
+ #:use-module (guix build utils)
+ #:use-module (guix build debug-link)
+ #:use-module (guix gexp)
+ #:use-module (guix store)
+ #:use-module (guix tests)
+ #:use-module (guix monads)
+ #:use-module (guix derivations)
+ #:use-module (gnu packages bootstrap)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:use-module (srfi srfi-64)
+ #:use-module (rnrs io ports)
+ #:use-module (ice-9 match))
+
+(define %guile-executable
+ (match (false-if-exception (readlink "/proc/self/exe"))
+ ((? string? program)
+ (and (file-exists? program) (elf-file? program)
+ program))
+ (_
+ #f)))
+
+(define read-elf
+ (compose parse-elf get-bytevector-all))
+
+(define %store
+ (open-connection-for-tests))
+
+(define-syntax-rule (test-assertm name exp)
+ (test-assert name
+ (run-with-store %store exp
+ #:guile-for-build (%guile-for-build))))
+
+
+(test-begin "debug-link")
+
+(unless %guile-executable (test-skip 1))
+(test-assert "elf-debuglink"
+ (let ((elf (call-with-input-file %guile-executable read-elf)))
+ (match (call-with-values (lambda () (elf-debuglink elf)) list)
+ ((#f #f) ;no '.gnu_debuglink' section
+ (pk 'no-debuglink #t))
+ (((? string? file) (? integer? crc))
+ (string-suffix? ".debug" file)))))
+
+(test-assertm "elf-debuglink"
+ ;; Check whether we can compute the CRC just like objcopy, and whether we
+ ;; can retrieve it.
+ (let* ((code (plain-file "test.c" "int main () { return 42; }"))
+ (exp (with-imported-modules '((guix build utils)
+ (guix build debug-link)
+ (guix elf))
+ #~(begin
+ (use-modules (guix build utils)
+ (guix build debug-link)
+ (guix elf)
+ (rnrs io ports))
+
+ (define read-elf
+ (compose parse-elf get-bytevector-all))
+
+ (setenv "PATH" (string-join '(#$%bootstrap-gcc
+ #$%bootstrap-binutils)
+ "/bin:" 'suffix))
+ (invoke "gcc" "-O0" "-g" #$code "-o" "exe")
+ (copy-file "exe" "exe.debug")
+ (invoke "strip" "--only-keep-debug" "exe.debug")
+ (invoke "strip" "--strip-debug" "exe")
+ (invoke "objcopy" "--add-gnu-debuglink=exe.debug"
+ "exe")
+ (call-with-values (lambda ()
+ (elf-debuglink
+ (call-with-input-file "exe"
+ read-elf)))
+ (lambda (file crc)
+ (call-with-output-file #$output
+ (lambda (port)
+ (let ((expected (call-with-input-file "exe.debug"
+ debuglink-crc32)))
+ (write (list file (= crc expected))
+ port))))))))))
+ (mlet* %store-monad ((drv (gexp->derivation "debuglink" exp))
+ (x (built-derivations (list drv))))
+ (call-with-input-file (derivation->output-path drv)
+ (lambda (port)
+ (return (match (read port)
+ (("exe.debug" #t) #t)
+ (x (pk 'fail x #f)))))))))
+
+(test-assertm "set-debuglink-crc"
+ ;; Check whether 'set-debuglink-crc' successfully updates the CRC.
+ (let* ((code (plain-file "test.c" "int main () { return 42; }"))
+ (debug (plain-file "exe.debug" "a"))
+ (exp (with-imported-modules '((guix build utils)
+ (guix build debug-link)
+ (guix elf))
+ #~(begin
+ (use-modules (guix build utils)
+ (guix build debug-link)
+ (guix elf)
+ (rnrs io ports))
+
+ (define read-elf
+ (compose parse-elf get-bytevector-all))
+
+ (setenv "PATH" (string-join '(#$%bootstrap-gcc
+ #$%bootstrap-binutils)
+ "/bin:" 'suffix))
+ (invoke "gcc" "-O0" "-g" #$code "-o" "exe")
+ (copy-file "exe" "exe.debug")
+ (invoke "strip" "--only-keep-debug" "exe.debug")
+ (invoke "strip" "--strip-debug" "exe")
+ (invoke "objcopy" "--add-gnu-debuglink=exe.debug"
+ "exe")
+ (set-debuglink-crc "exe" #$debug)
+ (call-with-values (lambda ()
+ (elf-debuglink
+ (call-with-input-file "exe"
+ read-elf)))
+ (lambda (file crc)
+ (call-with-output-file #$output
+ (lambda (port)
+ (write (list file crc) port)))))))))
+ (mlet* %store-monad ((drv (gexp->derivation "debuglink" exp))
+ (x (built-derivations (list drv))))
+ (call-with-input-file (derivation->output-path drv)
+ (lambda (port)
+ (return (match (read port)
+ (("exe.debug" crc)
+ (= crc (debuglink-crc32 (open-input-string "a"))))
+ (x
+ (pk 'fail x #f)))))))))
+
+(test-end "debug-link")
--
2.18.0