diff -ruN boost_1_63_0-orig/tools/build/src/engine/execcmd.c boost_1_63_0/tools/build/src/engine/execcmd.c
--- boost_1_63_0-orig/tools/build/src/engine/execcmd.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/execcmd.c	2021-01-05 16:45:20.000000000 -0600
@@ -10,6 +10,7 @@
 
 #include "jam.h"
 #include "execcmd.h"
+#include "output.h"
 
 #include <assert.h>
 #include <stdio.h>
diff -ruN boost_1_63_0-orig/tools/build/src/engine/execnt.c boost_1_63_0/tools/build/src/engine/execnt.c
--- boost_1_63_0-orig/tools/build/src/engine/execnt.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/execnt.c	2021-01-05 16:46:17.000000000 -0600
@@ -521,7 +521,7 @@
 
 static int maxline()
 {
-    static result;
+    static int result;
     if ( !result ) result = raw_maxline();
     return result;
 }
diff -ruN boost_1_63_0-orig/tools/build/src/engine/filent.c boost_1_63_0/tools/build/src/engine/filent.c
--- boost_1_63_0-orig/tools/build/src/engine/filent.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/filent.c	2021-01-05 16:46:56.000000000 -0600
@@ -50,6 +50,8 @@
 #include <io.h>
 
 
+int file_collect_archive_content_( file_archive_info_t * const archive );
+
 /*
  * file_collect_dir_content_() - collects directory content information
  */
diff -ruN boost_1_63_0-orig/tools/build/src/engine/filesys.h boost_1_63_0/tools/build/src/engine/filesys.h
--- boost_1_63_0-orig/tools/build/src/engine/filesys.h	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/filesys.h	2021-01-05 16:47:30.000000000 -0600
@@ -96,6 +96,8 @@
 file_info_t * filelist_front(  FILELIST * list );
 file_info_t * filelist_back(  FILELIST * list );
 
+int filelist_empty( FILELIST * list );
+
 #define FL0 ((FILELIST *)0)
 
 
diff -ruN boost_1_63_0-orig/tools/build/src/engine/fileunix.c boost_1_63_0/tools/build/src/engine/fileunix.c
--- boost_1_63_0-orig/tools/build/src/engine/fileunix.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/fileunix.c	2021-01-05 16:49:53.000000000 -0600
@@ -219,6 +219,7 @@
     timestamp_init( t, 1, 0 );
 }
 
+int file_collect_archive_content_( file_archive_info_t * const archive );
 
 /*
  * file_archscan() - scan an archive for files
diff -ruN boost_1_63_0-orig/tools/build/src/engine/function.c boost_1_63_0/tools/build/src/engine/function.c
--- boost_1_63_0-orig/tools/build/src/engine/function.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/function.c	2021-01-05 16:50:21.000000000 -0600
@@ -27,9 +27,9 @@
 #include <stdlib.h>
 #include <string.h>
 
-/* *
+/*
 #define FUNCTION_DEBUG_PROFILE
-/* */
+*/
 
 #ifndef FUNCTION_DEBUG_PROFILE
 #undef PROFILE_ENTER_LOCAL
diff -ruN boost_1_63_0-orig/tools/build/src/engine/hash.c boost_1_63_0/tools/build/src/engine/hash.c
--- boost_1_63_0-orig/tools/build/src/engine/hash.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/hash.c	2021-01-05 16:50:36.000000000 -0600
@@ -24,9 +24,9 @@
 
 #include <assert.h>
 
-/* *
+/*
 #define HASH_DEBUG_PROFILE 1
-/* */
+*/
 
 /* Header attached to all hash table data items. */
 
diff -ruN boost_1_63_0-orig/tools/build/src/engine/jam.c boost_1_63_0/tools/build/src/engine/jam.c
--- boost_1_63_0-orig/tools/build/src/engine/jam.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/jam.c	2021-01-05 16:54:07.000000000 -0600
@@ -120,6 +120,7 @@
 #include "strings.h"
 #include "timestamp.h"
 #include "variable.h"
+#include "execcmd.h"
 
 /* Macintosh is "special" */
 #ifdef OS_MAC
diff -ruN boost_1_63_0-orig/tools/build/src/engine/make.c boost_1_63_0/tools/build/src/engine/make.c
--- boost_1_63_0-orig/tools/build/src/engine/make.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/make.c	2021-01-05 16:55:03.000000000 -0600
@@ -44,6 +44,8 @@
 #include "search.h"
 #include "timestamp.h"
 #include "variable.h"
+#include "execcmd.h"
+#include "output.h"
 
 #include <assert.h>
 
@@ -82,7 +84,7 @@
     "exists",
 };
 
-#define spaces(x) ( "                    " + ( x > 20 ? 0 : 20-x ) )
+#define spaces(x) ( ((const char *)"                    ") + ( x > 20 ? 0 : 20-x ) )
 
 
 /*
diff -ruN boost_1_63_0-orig/tools/build/src/engine/modules/path.c boost_1_63_0/tools/build/src/engine/modules/path.c
--- boost_1_63_0-orig/tools/build/src/engine/modules/path.c	2016-12-22 06:33:21.000000000 -0600
+++ boost_1_63_0/tools/build/src/engine/modules/path.c	2021-01-05 16:49:11.000000000 -0600
@@ -8,7 +8,7 @@
 #include "../frames.h"
 #include "../lists.h"
 #include "../native.h"
-#include "../timestamp.h"
+#include "../filesys.h"
 
 
 LIST * path_exists( FRAME * frame, int flags )