- Issue #16262: fix out-of-src-tree builds, if mercurial is not installed.

Makefile.pre.in

@@ -308,7 +308,7 @@ AST_ASDL=	$(srcdir)/Parser/Python.asdl
 
 ASDLGEN_FILES=	$(srcdir)/Parser/asdl.py $(srcdir)/Parser/asdl_c.py
 # XXX Note that a build now requires Python exist before the build starts
-ASDLGEN=	@DISABLE_ASDLGEN@ $(srcdir)/Parser/asdl_c.py
+ASDLGEN=	@ASDLGEN@ $(srcdir)/Parser/asdl_c.py
 
 ##########################################################################
 # Python

Misc/NEWS

@@ -140,6 +140,8 @@ Tests
 Build
 -----
 
+- Issue #16262: fix out-of-src-tree builds, if mercurial is not installed.
+
 - Issue #15298: ensure _sysconfigdata is generated in build directory, not
   source directory.
 

Parser/asdl_c.py

@@ -5,7 +5,6 @@
 # handle fields that have a type but no name
 
 import os, sys
-import subprocess
 
 import asdl
 

configure

@@ -644,8 +644,8 @@ MKDIR_P
 INSTALL_DATA
 INSTALL_SCRIPT
 INSTALL_PROGRAM
-HAS_PYTHON
-DISABLE_ASDLGEN
+PYTHON
+ASDLGEN
 ac_ct_READELF
 READELF
 ARFLAGS
@@ -5923,16 +5923,17 @@ fi
 
 
 
-DISABLE_ASDLGEN=""
-# Extract the first word of "python", so it can be a program name with args.
-set dummy python; ac_word=$2
+for ac_prog in python$PACKAGE_VERSION python3 python
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 $as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_HAS_PYTHON+:} false; then :
+if ${ac_cv_prog_PYTHON+:} false; then :
   $as_echo_n "(cached) " >&6
 else
-  if test -n "$HAS_PYTHON"; then
-  ac_cv_prog_HAS_PYTHON="$HAS_PYTHON" # Let the user override the test.
+  if test -n "$PYTHON"; then
+  ac_cv_prog_PYTHON="$PYTHON" # Let the user override the test.
 else
 as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
 for as_dir in $PATH
@@ -5941,7 +5942,7 @@ do
   test -z "$as_dir" && as_dir=.
     for ac_exec_ext in '' $ac_executable_extensions; do
   if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
-    ac_cv_prog_HAS_PYTHON="found"
+    ac_cv_prog_PYTHON="$ac_prog"
     $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
   fi
@@ -5949,22 +5950,26 @@ done
   done
 IFS=$as_save_IFS
 
-  test -z "$ac_cv_prog_HAS_PYTHON" && ac_cv_prog_HAS_PYTHON="not-found"
 fi
 fi
-HAS_PYTHON=$ac_cv_prog_HAS_PYTHON
-if test -n "$HAS_PYTHON"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $HAS_PYTHON" >&5
-$as_echo "$HAS_PYTHON" >&6; }
+PYTHON=$ac_cv_prog_PYTHON
+if test -n "$PYTHON"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PYTHON" >&5
+$as_echo "$PYTHON" >&6; }
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 fi
 
 
-if test $HAS_HG != found -o $HAS_PYTHON != found
-then
-    DISABLE_ASDLGEN="@echo hg: $HAS_HG, python: $HAS_PYTHON! cannot run \$(srcdir)/Parser/asdl_c.py #"
+  test -n "$PYTHON" && break
+done
+test -n "$PYTHON" || PYTHON="not-found"
+
+if $PYTHON = not-found; then
+    ASDLGEN="@echo python: $PYTHON! cannot run \$(srcdir)/Parser/asdl_c.py #"
+else
+    ASDLGEN="$PYTHON"
 fi
 
 

configure.ac

@@ -1000,12 +1000,12 @@ if test "$cross_compiling" = yes; then
 fi
 AC_SUBST(READELF)
 
-AC_SUBST(DISABLE_ASDLGEN)
-DISABLE_ASDLGEN=""
-AC_CHECK_PROG(HAS_PYTHON, python, found, not-found)
-if test $HAS_HG != found -o $HAS_PYTHON != found
-then
-    DISABLE_ASDLGEN="@echo hg: $HAS_HG, python: $HAS_PYTHON! cannot run \$(srcdir)/Parser/asdl_c.py #"
+AC_SUBST(ASDLGEN)
+AC_CHECK_PROGS(PYTHON, python$PACKAGE_VERSION python3 python, not-found)
+if $PYTHON = not-found; then
+    ASDLGEN="@echo python: $PYTHON! cannot run \$(srcdir)/Parser/asdl_c.py #"
+else
+    ASDLGEN="$PYTHON"
 fi