From f42d57c7dbd571b449270c8899a67e537561c2b2 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 24 Jan 2020 16:41:38 -0800 Subject: [PATCH] Install C source code for C-h f etc. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Without this change, on typical GNU/Linux distributions like Debian, the first button of ‘C-h f car RET’ does not work because the source code for ‘car’ is not installed (Bug#37527). Fix this by installing the (compressed) C source code alongside the (compressed) Lisp source code that is already installed. This adds about 3 MB (about 2%) to the size of the installed files on my platform. * Makefile.in (emacs_srcdir): New macro. (epaths-force): Substitute PATH_EMACS_SOURCE. (install-c-src): New rule, that installs a copy of the C source code if emacs_srcdir says to. (install-arch-indep): Depend on it. * configure.ac (emacs_srcdir): New var. Add support for --disable-install-srcdir. * lisp/emacs-lisp/find-func.el (find-function-C-source-directory): Look in emacs-source-directory first. (find-function-C-source): Also look for gzipped source files. * lisp/startup.el (normal-top-level): Also recode emacs-source-directory. * src/epaths.in (PATH_EMACS_SOURCE): New macro. * src/lread.c: Include dosname.h, for IS_ABSOLUTE_FILE_NAME. (syms_of_lread): New var emacs-source-directory. --- INSTALL | 65 ++++++++++++++++++------------------ Makefile.in | 31 +++++++++++++++-- configure.ac | 14 ++++++++ etc/NEWS | 9 +++++ lisp/emacs-lisp/find-func.el | 11 ++++-- lisp/startup.el | 3 +- src/epaths.in | 4 +++ src/lread.c | 10 +++++- 8 files changed, 108 insertions(+), 39 deletions(-) diff --git a/INSTALL b/INSTALL index 2d257f9ce68..cb12e4a17aa 100644 --- a/INSTALL +++ b/INSTALL @@ -214,41 +214,42 @@ like 'apt-get build-dep emacs' (on older systems, replace 'emacs' with eg 'emacs25'). On Red Hat-based systems, the corresponding command is 'dnf builddep emacs' (on older systems, use 'yum-builddep' instead). + +DEBUGGING AN INSTALLED EMACS + +* Installed Emacs source code + +Emacs installs a compressed copy of much of its source code, to make +it easy for users to read the source code of Emacs via commands like +M-x describe-function (C-h f) to display the definition of a function. +This compressed copy ordinarily includes both the Elisp source code +that Emacs is mostly written in, as well as the C source code for the +core Emacs executable. + * GNU/Linux source and debug packages Many GNU/Linux systems provide separate packages containing the -sources and debug symbols of Emacs. They are useful if you want to -check the source code of Emacs primitive functions or debug Emacs on -the C level. - -The names of the packages that you need vary according to the -GNU/Linux distribution that you use. On Debian-based systems, you can -install a source package of Emacs with a command like 'apt-get source -emacs' (on older systems, replace 'emacs' with eg 'emacs25'). The -target directory for unpacking the source tree is the current -directory. On Red Hat-based systems, the corresponding command is -'dnf install emacs-debugsource', with target directory /usr/src/debug -(this requires to add the *-debuginfo repositories first, via 'dnf -config-manager --set-enabled fedora-debuginfo updates-debuginfo'). - -Once you have installed the source package, for example at -/path/to/emacs-26.1, add the following line to your startup file: - - (setq find-function-C-source-directory - "/path/to/emacs-26.1/src") - -The installation directory of the Emacs source package will contain -the exact package name and version number Emacs is installed on your -system. If a new Emacs package is installed, the source package must -be reinstalled as well, and the setting in your startup file must be -updated. - -Emacs debugging symbols are distributed by a debug package. It does -not exist for every released Emacs package, this depends on the -distribution. On Debian-based systems, you can install a debug -package of Emacs with a command like 'apt-get install emacs-dbg' (on -older systems, replace 'emacs' with eg 'emacs25'). On Red Hat-based -systems, the corresponding command is 'dnf debuginfo-install emacs'. +sources and debug symbols of Emacs. They can help you debug the +installed Emacs on the C level. The procedures for installing these +packages depend on the GNU/Linux system that you use. + +Emacs debugging symbols are distributed by a debug package if one +exists for your system. On Debian-based systems, you can +install a debug package of Emacs with a command like 'apt-get install +emacs-dbg' (on older systems, replace 'emacs' with e.g. 'emacs25'). +On Red Hat-based systems, the corresponding command is 'dnf +debuginfo-install emacs'; this may require adding the *-debuginfo +repositories first, via 'dnf config-manager --set-enabled +fedora-debuginfo updates-debuginfo'. + +Some systems also have an Emacs source package that is also helpful +when debugging the installed Emacs. To unpack an Emacs source package +into the current directory on Debian-based systems, you can use a +command like 'apt-get source emacs' (on older systems, replace 'emacs' +with e.g. 'emacs25'); you may first need to add the appropriate +'source' URIs to your sources.list. On Red Hat-based systems, +installing the debugging symbols automatically installs the +corresponding source package in the appropriate location. DETAILED BUILDING AND INSTALLATION: diff --git a/Makefile.in b/Makefile.in index 2c82c49fba5..adefa98fd02 100644 --- a/Makefile.in +++ b/Makefile.in @@ -266,6 +266,9 @@ etcdir=@etcdir@ # once. archlibdir=@archlibdir@ +# Where to install Emacs C source code, or empty if it is not installed. +emacs_srcdir=@emacs_srcdir@ + # Where to put the etc/DOC file. etcdocdir=@etcdocdir@ @@ -374,6 +377,7 @@ epaths-force: -e 's;\(#.*PATH_BITMAPS\).*$$;\1 "${bitmapdir}";' \ -e 's;\(#.*PATH_X_DEFAULTS\).*$$;\1 "${x_default_search_path}";' \ -e 's;\(#.*PATH_GAME\).*$$;\1 $(PATH_GAME);' \ + -e 's;\(#.*PATH_EMACS_SOURCE\).*$$;\1 "${emacs_srcdir}";' \ -e 's;\(#.*PATH_DOC\).*$$;\1 "${etcdocdir}";') && \ ${srcdir}/build-aux/move-if-change epaths.h.$$$$ src/epaths.h @@ -461,7 +465,7 @@ $(srcdir)/configure: $(srcdir)/configure.ac $(srcdir)/m4/*.m4 # ==================== Installation ==================== .PHONY: install install-arch-dep install-arch-indep install-etcdoc install-info -.PHONY: install-man install-etc install-strip install-$(NTDIR) +.PHONY: install-man install-c-src install-etc install-strip install-$(NTDIR) .PHONY: uninstall uninstall-$(NTDIR) ## If we let lib-src do its own installation, that means we @@ -568,7 +572,8 @@ set_installuser=for installuser in $${LOGNAME} $${USERNAME} $${USER} \ ## work correctly, and therefore no idea when tar can be replaced. ## See also these comments from 2004 about cp -r working fine: ## https://lists.gnu.org/r/autoconf-patches/2004-11/msg00005.html -install-arch-indep: lisp install-info install-man ${INSTALL_ARCH_INDEP_EXTRA} +install-arch-indep: lisp install-info install-man install-c-src \ + $(INSTALL_ARCH_INDEP_EXTRA) umask 022 && $(MKDIR_P) "$(DESTDIR)$(includedir)" $(INSTALL_DATA) src/emacs-module.h "$(DESTDIR)$(includedir)/emacs-module.h" -set ${COPYDESTS} ; \ @@ -700,6 +705,28 @@ install-man: ${GZIP_PROG} -9n "$(DESTDIR)${man1dir}/$${dest}" || true; \ done +install-c-src: +ifneq (,$(emacs_srcdir)) + -unset CDPATH; \ + umask 022; $(MKDIR_P) "$(DESTDIR)$(emacs_srcdir)/src" && \ + exp_sourcesrcdir=`cd "$(DESTDIR)$(emacs_srcdir)/src" && /bin/pwd` && \ + [ "`cd $(srcdir)/src && /bin/pwd`" = "$$exp_sourcesrcdir" ] || { \ + $(set_installuser); \ + printf 'Copying compressed C sources to %s ...\n' \ + "$(DESTDIR)$(emacs_srcdir)/src"; \ + for file in `cd $(srcdir) && echo src/*.[cm]`; do \ + installed_file="$(DESTDIR)$(emacs_srcdir)/$$file" && \ + $(INSTALL_DATA) "$$file" "$$installed_file" && \ + [ -z "$(GZIP_PROG)" ] || { \ + rm -f "$$installed_file.gz" && \ + $(GZIP_PROG) -9n "$$installed_file" && \ + installed_file=$$installed_file.gz; \ + } || exit; \ + chown $$installuser "$$installed_file" || true; \ + done; \ + } +endif + ## Install those items from etc/ that need to end up elsewhere. ## If you prefer, choose "emacs22" at installation time. diff --git a/configure.ac b/configure.ac index 27e44dacfb2..4de83c6b261 100644 --- a/configure.ac +++ b/configure.ac @@ -194,6 +194,7 @@ locallisppath='${datadir}/emacs/${version}/site-lisp:'\ lisppath='${locallisppath}:${standardlisppath}' etcdir='${datadir}/emacs/${version}/etc' archlibdir='${libexecdir}/emacs/${version}/${configuration}' +emacs_srcdir='${datadir}/emacs/${version}' etcdocdir='${datadir}/emacs/${version}/etc' gamedir='${localstatedir}/games/emacs' @@ -540,6 +541,15 @@ elif test "${enableval}" != "yes"; then locallisppath=${enableval} locallisppathset=yes fi) +AC_ARG_ENABLE([install-srcdir], + [AS_HELP_STRING([--disable-install-srcdir], + [do not install low-level Emacs source code useful for debugging.])], + [case $enableval in + yes) ;; + no) emacs_srcdir=;; + *) AC_MSG_ERROR([invalid install-srcdir]);; + esac]) + AC_ARG_ENABLE(checking, [AS_HELP_STRING([--enable-checking@<:@=LIST@:>@], [enable expensive checks. With LIST, @@ -2048,6 +2058,9 @@ if test "${HAVE_NS}" = yes; then dnl This one isn't really used, only archlibdir is. libexecdir="\${ns_appbindir}/libexec" archlibdir="\${ns_appbindir}/libexec" + case $emacs_srcdir in + ?*) emacs_srcdir="\${ns_appresdir}";; + esac etcdocdir="\${ns_appresdir}/etc" etcdir="\${ns_appresdir}/etc" dnl FIXME maybe set datarootdir instead. @@ -5230,6 +5243,7 @@ AC_SUBST(lisppath) AC_SUBST(x_default_search_path) AC_SUBST(etcdir) AC_SUBST(archlibdir) +AC_SUBST([emacs_srcdir]) AC_SUBST(etcdocdir) AC_SUBST(bitmapdir) AC_SUBST(gamedir) diff --git a/etc/NEWS b/etc/NEWS index 5395f2ccfb2..c3a71ade8ac 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -58,6 +58,12 @@ shaping, so 'configure' now recommends that combination. ** The ftx font backend driver has been removed. It was declared obsolete in Emacs 27.1. +--- +** Emacs now installs a copy of its C source code, used for debugging help. +For example, pressing the first button in the *Help* buffer generated +by 'C-h f car RET' now takes you to a copy of the C-language +implementation of the function 'car'. + * Startup Changes in Emacs 28.1 @@ -142,6 +148,9 @@ called when the function object is garbage-collected. Use ** 'parse-time-string' can now parse ISO 8601 format strings, such as "2020-01-15T16:12:21-08:00". +** The new variable 'emacs-source-directory' gives the Emacs source +code location. + * Changes in Emacs 28.1 on Non-Free Operating Systems diff --git a/lisp/emacs-lisp/find-func.el b/lisp/emacs-lisp/find-func.el index 167ead3ce02..be53324f141 100644 --- a/lisp/emacs-lisp/find-func.el +++ b/lisp/emacs-lisp/find-func.el @@ -219,8 +219,10 @@ LIBRARY should be a string (the name of the library)." (locate-file basename (list dir) (find-library-suffixes))))))) (defvar find-function-C-source-directory - (let ((dir (expand-file-name "src" source-directory))) - (if (file-accessible-directory-p dir) dir)) + (let ((dir (expand-file-name "src" emacs-source-directory))) + (if (file-accessible-directory-p dir) dir + (setq dir (expand-file-name "src" source-directory)) + (if (file-accessible-directory-p dir) dir))) "Directory where the C source files of Emacs can be found. If nil, do not try to find the source code of functions and variables defined in C.") @@ -245,7 +247,10 @@ TYPE should be nil to find a function, or `defvar' to find a variable." (let ((dir (or find-function-C-source-directory (read-directory-name "Emacs C source dir: " nil nil t)))) (setq file (expand-file-name file dir)) - (if (file-readable-p file) + (if (or (file-readable-p file) + (let ((file-gz (concat file ".gz"))) + (and (file-readable-p file-gz) + (setq file file-gz)))) (if (null find-function-C-source-directory) (setq find-function-C-source-directory dir)) (error "The C source file %s is not available" diff --git a/lisp/startup.el b/lisp/startup.el index 1f545c66922..676fb35e000 100644 --- a/lisp/startup.el +++ b/lisp/startup.el @@ -623,7 +623,8 @@ It is the default value of the variable `top-level'." (set pathsym (mapcar (lambda (dir) (decode-coding-string dir coding t)) path))))) - (dolist (filesym '(data-directory doc-directory exec-directory + (dolist (filesym '(data-directory doc-directory emacs-source-directory + exec-directory installation-directory invocation-directory invocation-name source-directory diff --git a/src/epaths.in b/src/epaths.in index 3cadd160ecf..554fdd7228a 100644 --- a/src/epaths.in +++ b/src/epaths.in @@ -73,5 +73,9 @@ along with GNU Emacs. If not, see . */ /* Where Emacs should store game score files. */ #define PATH_GAME "/usr/local/var/games/emacs" +/* Where Emacs should look for its own installed source code, + or the empty string if the source code is not installed. */ +#define PATH_EMACS_SOURCE "/usr/local/share/emacs" + /* Where Emacs should look for the application default file. */ #define PATH_X_DEFAULTS "/usr/lib/X11/%L/%T/%N%C%S:/usr/lib/X11/%l/%T/%N%C%S:/usr/lib/X11/%T/%N%C%S:/usr/lib/X11/%L/%T/%N%S:/usr/lib/X11/%l/%T/%N%S:/usr/lib/X11/%T/%N%S" diff --git a/src/lread.c b/src/lread.c index 69dd73912bc..274491f0229 100644 --- a/src/lread.c +++ b/src/lread.c @@ -44,6 +44,7 @@ along with GNU Emacs. If not, see . */ #include "blockinput.h" #include "pdumper.h" #include +#include #include #ifdef MSDOS @@ -4992,11 +4993,18 @@ and is not meant for users to change. */); DEFVAR_LISP ("source-directory", Vsource_directory, doc: /* Directory in which Emacs sources were found when Emacs was built. -You cannot count on them to still be there! */); +You cannot count on them to still be there! Also see +`emacs-source-directory'. */); Vsource_directory = Fexpand_file_name (build_string ("../"), Fcar (decode_env_path (0, PATH_DUMPLOADSEARCH, 0))); + DEFVAR_LISP ("emacs-source-directory", Vemacs_source_directory, + doc: /* Directory where Emacs sources can be found. */); + Vemacs_source_directory = (IS_ABSOLUTE_FILE_NAME (PATH_EMACS_SOURCE) + ? build_string (PATH_EMACS_SOURCE) + : Vsource_directory); + DEFVAR_LISP ("preloaded-file-list", Vpreloaded_file_list, doc: /* List of files that were preloaded (when dumping Emacs). */); Vpreloaded_file_list = Qnil; -- 2.39.2