From a2f6511f5e39619063d47dc3a994e46132d1588f Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <janneke@gnu.org>
Date: Sat, 9 Dec 2017 22:38:51 +0100
Subject: [PATCH] mescc: Allow invoking git mescc.mes from elsewhere.

* src/mes.c (load_env): Look in MES_PREFIX too.  Add debug printing.
* scripts/mescc.mes: Consider MES_PREFIX.
* guile/mescc.scm (%prefix): Consider MES_PREFIX.
* module/mes/base-0.mes (string->list): New function, move from type-0.mes.
  (%moduledir): Consider MES_PREFIX.
* module/mes/type-0.mes (string->list): Remove.
---
 guile/mescc.scm       |  2 +-
 module/mes/base-0.mes | 18 ++++++++++++++---
 module/mes/type-0.mes |  3 ---
 scripts/mescc.mes     | 21 ++++++++++++++------
 src/mes.c             | 45 ++++++++++++++++++++++++++++++++++++++++---
 5 files changed, 73 insertions(+), 16 deletions(-)

diff --git a/guile/mescc.scm b/guile/mescc.scm
index 55447215..770e8244 100755
--- a/guile/mescc.scm
+++ b/guile/mescc.scm
@@ -45,7 +45,7 @@ GUILE='~/src/guile-1.8/build/pre-inst-guile --debug -q' guile/mescc.scm
   #:use-module (srfi srfi-26)
   #:export (main))
 
-(define %prefix (if (string-prefix? "@PREFIX" "@PREFIX@") (or (getenv "PREFIX") "") "@PREFIX@"))
+(define %prefix (if (string-prefix? "@PREFIX" "@PREFIX@") (or (getenv "MES_PREFIX") "") "@PREFIX@"))
 (module-define! (resolve-module '(language c99 compiler)) '%prefix %prefix)
 
 (define (parse-opts args)
diff --git a/module/mes/base-0.mes b/module/mes/base-0.mes
index f575d32a..0334cc28 100644
--- a/module/mes/base-0.mes
+++ b/module/mes/base-0.mes
@@ -109,7 +109,19 @@
       (if (null? (cdr rest)) (car rest)
           (append2 (car rest) (apply append (cdr rest))))))
 
-(include "module/mes/type-0.mes")
+(define (string->list s)
+  (core:car s))
+
+(define %prefix (getenv "MES_PREFIX"))
+(define %moduledir
+  (if (not %prefix) "module/"
+      (list->string
+       (append (string->list %prefix)
+               (string->list "/module") ; `module/' gets replaced upon install
+               (string->list "/")))))
+
+(include (list->string
+          (append (string->list %moduledir) (string->list "/mes/type-0.mes"))))
 
 (define (symbol->string s)
   (apply string (symbol->list s)))
@@ -117,8 +129,8 @@
 (define (string-append . rest)
   (apply string (apply append (map1 string->list rest))))
 
-(define %moduledir "module/")
-(define %version (if (eq? (car (string->list "@VERSION@")) #\@) "git" "@VERSION@"))
+(define %version (if (eq? (car (string->list "@VERSION@")) #\@) "git"
+                     "@VERSION@"))
 (define (effective-version) %version)
 
 (if (getenv "MES_DEBUG")
diff --git a/module/mes/type-0.mes b/module/mes/type-0.mes
index c82c9468..122fc261 100644
--- a/module/mes/type-0.mes
+++ b/module/mes/type-0.mes
@@ -122,9 +122,6 @@
 (define (string . lst)
   (core:make-cell <cell:string> lst 0))
 
-(define (string->list s)
-  (core:car s))
-
 (define (string->symbol s)
   (if (not (pair? (core:car s))) '()
       (core:lookup-symbol (core:car s))))
diff --git a/scripts/mescc.mes b/scripts/mescc.mes
index 677ea56d..8e908838 100755
--- a/scripts/mescc.mes
+++ b/scripts/mescc.mes
@@ -1,12 +1,21 @@
 #! /bin/sh
 # -*-scheme-*-
 MES=${MES-$(dirname $0)/mes}
-moduledir=module/
-echo '()' | cat $moduledir/mes/base-0.mes $0 /dev/stdin | $MES $MES_FLAGS -- "$@"
+PREFIX=${PREFIX-@PREFIX@}
+MES_PREFIX=${MES_PREFIX-$PREFIX}
+if [ "$MES_PREFIX" = @PREFIX""@ ]
+then
+    MES_PREFIX=$(cd $(dirname $0)/.. && pwd)
+    export MES_PREFIX
+    MES_MODULEDIR=${MES_MODULEDIR-$MES_PREFIX/"module"}
+    export MES_MODULEDIR
+else
+    MES_MODULEDIR=${MES_MODULEDIR-$MES_PREFIX/share/mes/"module"}
+    export MES_MODULEDIR
+fi
+echo '()' | cat $MES_MODULEDIR/mes/base-0.mes $0 /dev/stdin | $MES $MES_FLAGS -- "$@"
 #paredit:||
-r=$?
-([ -f a.out ] && chmod +x a.out)
-exit $r
+exit $?
 !#
 
 ;;; Mes --- Maxwell Equations of Software
@@ -49,7 +58,7 @@ exit $r
 
 (format (current-error-port) "mescc.mes...\n")
 
-(define %prefix (if (string-prefix? "@PREFIX" "@PREFIX@") (or (getenv "PREFIX") "") "@PREFIX@"))
+(define %prefix (if (string-prefix? "@PREFIX" "@PREFIX@") (or (getenv "MES_PREFIX") "") "@PREFIX@"))
 
 (define (parse-opts args)
   (let* ((option-spec
diff --git a/src/mes.c b/src/mes.c
index d410153a..8b2201e4 100644
--- a/src/mes.c
+++ b/src/mes.c
@@ -1267,9 +1267,48 @@ SCM
 load_env (SCM a) ///((internal))
 {
   r0 = a;
-  g_stdin = open ("module/mes/read-0.mes", O_RDONLY);
-  char *read0 = MODULEDIR "mes/read-0.mes";
-  g_stdin = g_stdin >= 0 ? g_stdin : open (read0, O_RDONLY);
+  g_stdin = -1;
+  if (getenv ("MES_PREFIX"))
+    {
+      char buf[128];
+      strcpy (buf, getenv ("MES_PREFIX"));
+      strcpy (buf + strlen (buf), "/module");
+      strcpy (buf + strlen (buf), "/mes/read-0.mes");
+      if (getenv ("MES_DEBUG"))
+        {
+          eputs ("MES_PREFIX reading read-0:");
+          eputs (buf);
+          eputs ("\n");
+        }
+      g_stdin = open (buf, O_RDONLY);
+    }
+  if (g_stdin < 0)
+    {
+      char *read0 = MODULEDIR "mes/read-0.mes";
+      if (getenv ("MES_DEBUG"))
+        {
+          eputs ("MODULEDIR reading read-0:");
+          eputs (read0);
+          eputs ("\n");
+        }
+      g_stdin = open (read0, O_RDONLY);
+    }
+  if (g_stdin < 0)
+    {
+      if (getenv ("MES_DEBUG"))
+        {
+          eputs (". reading read-0:");
+          eputs ("module/mes/read-0.mes");
+          eputs ("\n");
+        }
+      g_stdin = open ("module/mes/read-0.mes", O_RDONLY);
+    }
+  if (g_stdin < 0)
+    {
+      eputs ("boot failed, read-0.mes not found\n");
+      exit (1);
+    }
+
   if (!g_function) r0 = mes_builtins (r0);
   r2 = read_input_file_env (r0);
   g_stdin = STDIN;