From 31607778ef262e5c25a65eb479f9531c5803f4a6 Mon Sep 17 00:00:00 2001

From: Glenn Morris <rgm@gnu.org>

Date: Mon, 11 Oct 2021 14:03:26 +0200

Subject: [PATCH] Make the installed pmdp file use a fingerprint

* Makefile.in (EMACS_PDMP): Use --fingerprint.

* doc/emacs/cmdargs.texi (Action Arguments): Document --fingerprint.

* src/emacs.c (load_pdump): Load the fingerprinted version of the

pdmp file (bug#42790).

(main): Support --fingerprint.

* src/pdumper.c (dump_fingerprint): Make non-static.

* src/pdumper.h: Declare dump_fingerprint.

---

 Makefile.in            |  3 ++-

 doc/emacs/cmdargs.texi |  5 +++++

 src/emacs.c            | 31 +++++++++++++++++++++++++++++--

 src/pdumper.c          |  2 +-

 src/pdumper.h          |  3 +++

 5 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/Makefile.in b/Makefile.in

index c902b46ced..f8b8058d96 100644

--- a/Makefile.in

+++ b/Makefile.in

@@ -313,6 +313,7 @@ TRANSFORM =

 EMACS_NAME = `echo emacs | sed '$(TRANSFORM)'`

 EMACS = ${EMACS_NAME}${EXEEXT}

 EMACSFULL = `echo emacs-${version} | sed '$(TRANSFORM)'`${EXEEXT}

+EMACS_PDMP = `./src/emacs${EXEEXT} --fingerprint 2>&1 | sed 's/.* //'`.pdmp

 # Subdirectories to make recursively.

 SUBDIR = $(NTDIR) lib lib-src src lisp

@@ -521,7 +522,7 @@ install-arch-dep:

 ifeq (${ns_self_contained},no)

 	${INSTALL_PROGRAM} $(INSTALL_STRIP) src/emacs${EXEEXT} "$(DESTDIR)${bindir}/$(EMACSFULL)"

 ifeq (${DUMPING},pdumper)

-	${INSTALL_DATA} src/emacs.pdmp "$(DESTDIR)${libexecdir}/emacs/${version}/${configuration}"/emacs.pdmp

+	${INSTALL_DATA} src/emacs.pdmp "$(DESTDIR)${libexecdir}/emacs/${version}/${configuration}"/emacs-${EMACS_PDMP}

 endif

 	-chmod 755 "$(DESTDIR)${bindir}/$(EMACSFULL)"

 ifndef NO_BIN_LINK

diff --git a/doc/emacs/cmdargs.texi b/doc/emacs/cmdargs.texi

index ffab2b2213..b3f84098e7 100644

--- a/doc/emacs/cmdargs.texi

+++ b/doc/emacs/cmdargs.texi

@@ -185,6 +185,11 @@ Action Arguments

 @item --version

 @opindex --version

 Print Emacs version, then exit successfully.

+

+@item --fingerprint

+@opindex --fingerprint

+Print the Emacs ``fingerprint'', which is used to uniquely identify

+the compiled version of Emacs.

 @end table

 @node Initial Options

diff --git a/src/emacs.c b/src/emacs.c

index 0a90b0913b..1907065a95 100644

--- a/src/emacs.c

+++ b/src/emacs.c

@@ -133,6 +133,7 @@ #define MAIN_PROGRAM

 #endif

 #include "pdumper.h"

+#include "fingerprint.h"

 #include "epaths.h"

 static const char emacs_version[] = PACKAGE_VERSION;

@@ -255,6 +256,7 @@ #define MAIN_PROGRAM

 #ifdef HAVE_PDUMPER

     "\

 --dump-file FILE            read dumped state from FILE\n\

+--fingerprint               output fingerprint and exit\n\

 ",

 #endif

 #if SECCOMP_USABLE

@@ -830,6 +832,8 @@ load_pdump (int argc, char **argv)

   const char *const suffix = ".pdmp";

   int result;

   char *emacs_executable = argv[0];

+  ptrdiff_t hexbuf_size;

+  char *hexbuf;

   const char *strip_suffix =

 #if defined DOS_NT || defined CYGWIN

     ".exe"

@@ -927,9 +931,15 @@ load_pdump (int argc, char **argv)

   /* Look for "emacs.pdmp" in PATH_EXEC.  We hardcode "emacs" in

      "emacs.pdmp" so that the Emacs binary still works if the user

      copies and renames it.  */

+  hexbuf_size = 2 * sizeof fingerprint;

+  hexbuf = xmalloc (hexbuf_size + 1);

+  hexbuf_digest (hexbuf, (char *)fingerprint, sizeof fingerprint);

+  hexbuf[hexbuf_size] = '\0';

   needed = (strlen (path_exec)

 	    + 1

 	    + strlen (argv0_base)

+	    + 1

+	    + strlen (hexbuf)

 	    + strlen (suffix)

 	    + 1);

   if (bufsize < needed)

@@ -937,8 +947,8 @@ load_pdump (int argc, char **argv)

       xfree (dump_file);

       dump_file = xpalloc (NULL, &bufsize, needed - bufsize, -1, 1);

     }

-  sprintf (dump_file, "%s%c%s%s",

-           path_exec, DIRECTORY_SEP, argv0_base, suffix);

+  sprintf (dump_file, "%s%c%s-%s%s",

+           path_exec, DIRECTORY_SEP, argv0_base, hexbuf, suffix);

 #if !defined (NS_SELF_CONTAINED)

   if (!(emacs_executable && *emacs_executable))

     {

@@ -1424,6 +1434,23 @@ main (int argc, char **argv)

       exit (0);

     }

+#ifdef HAVE_PDUMPER

+  if (argmatch (argv, argc, "-fingerprint", "--fingerprint", 4,

+		NULL, &skip_args))

+    {

+      if (initialized)

+        {

+          dump_fingerprint ("fingerprint", (unsigned char *)fingerprint);

+          exit (0);

+        }

+      else

+        {

+          fputs ("Not initialized\n", stderr);

+          exit (1);

+        }

+    }

+#endif

+

   emacs_wd = emacs_get_current_dir_name ();

 #ifdef HAVE_PDUMPER

   if (dumped_with_pdumper_p ())

diff --git a/src/pdumper.c b/src/pdumper.c

index b0167299d7..56a5e2ec6d 100644

--- a/src/pdumper.c

+++ b/src/pdumper.c

@@ -312,7 +312,7 @@ dump_reloc_set_offset (struct dump_reloc *reloc, dump_off offset)

     error ("dump relocation out of range");

 }

-static void

+void

 dump_fingerprint (char const *label,

 		  unsigned char const xfingerprint[sizeof fingerprint])

 {

diff --git a/src/pdumper.h b/src/pdumper.h

index 8383283894..002e1d88ce 100644

--- a/src/pdumper.h

+++ b/src/pdumper.h

@@ -50,6 +50,9 @@ #define PDUMPER_IGNORE(thing) ((void) &(thing))

 #define PDUMPER_REMEMBER_SCALAR(thing)                  \

   pdumper_remember_scalar (&(thing), sizeof (thing))

+extern void dump_fingerprint (const char *label,

+                              const unsigned char *xfingerprint);

+

 extern void pdumper_remember_scalar_impl (void *data, ptrdiff_t nbytes);

 INLINE void

-- 

2.37.3