Patch to require Python 3.4 or later to build glibc

diff --git a/INSTALL b/INSTALL
index 50bd113d55..3884ada8d8 100644
--- a/INSTALL
+++ b/INSTALL
@@ -531,11 +531,11 @@  build the GNU C Library:
      work with any version of 'sed'.  As of release time, 'sed' version
      4.5 is the newest verified to work to build the GNU C Library.
 
-   * Python 2.7/3.4 or later
+   * Python 3.4 or later
 
-     Python is required to build the GNU C Library manual and to run
-     some tests.  As of release time, Python 3.6 is the newest verified
-     to work for testing the GNU C Library.
+     Python is required to build the GNU C Library.  As of release time,
+     Python 3.6 is the newest verified to work for building and testing
+     the GNU C Library.
 
    * PExpect 4.0
 
diff --git a/NEWS b/NEWS
index 270abc1905..3d13b321a7 100644
--- a/NEWS
+++ b/NEWS
@@ -48,7 +48,7 @@  Deprecated and removed features, and other changes affecting compatibility:
 
 Changes to build and runtime requirements:
 
-* Python is required to build the GNU C Library manual.
+* Python 3.4 or later is required to build the GNU C Library.
 
 Security related changes:
 
diff --git a/benchtests/Makefile b/benchtests/Makefile
index bcd6a9c26d..09da2f765f 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -174,14 +174,7 @@  $(error Invalid BENCHSET value)
 endif
 endif
 
-# Define the bench target only if the target has a usable python installation.
-ifdef PYTHON
 bench: bench-build bench-set bench-func bench-malloc
-else
-bench:
-	@echo "The bench target needs python to run."
-	@exit 1
-endif
 
 # Target to only build the benchmark without running it.  We generate locales
 # only if we're building natively.
diff --git a/configure b/configure
index f30c31afdc..535e2f62e0 100755
--- a/configure
+++ b/configure
@@ -5344,19 +5344,30 @@  fi
 
   test -n "$PYTHON_PROG" && break
 done
-test -n "$PYTHON_PROG" || PYTHON_PROG="no"
 
-case "x$PYTHON_PROG" in
-xno|x|x:) PYTHON_PROG=no ;;
-*) ;;
-esac
-
-if test "x$PYTHON_PROG" = xno; then
-  aux_missing="$aux_missing python"
+if test -z "$PYTHON_PROG"; then
+  ac_verc_fail=yes
 else
-  PYTHON="$PYTHON_PROG -B"
+  # Found it, now check the version.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking version of $PYTHON_PROG" >&5
+$as_echo_n "checking version of $PYTHON_PROG... " >&6; }
+  ac_prog_version=`$PYTHON_PROG --version 2>&1 | sed -n 's/^.*Python \([0-9][0-9.]*\).*$/\1/p'`
+  case $ac_prog_version in
+    '') ac_prog_version="v. ?.??, bad"; ac_verc_fail=yes;;
+    3.[4-9]*|3.[1-9][0-9]*|[4-9].*|[1-9][0-9]*)
+       ac_prog_version="$ac_prog_version, ok"; ac_verc_fail=no;;
+    *) ac_prog_version="$ac_prog_version, bad"; ac_verc_fail=yes;;
 
+  esac
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_prog_version" >&5
+$as_echo "$ac_prog_version" >&6; }
 fi
+if test $ac_verc_fail = yes; then
+  critic_missing="$critic_missing python"
+fi
+
+PYTHON="$PYTHON_PROG -B"
+
 
 test -n "$critic_missing" && as_fn_error $? "
 *** These critical programs are missing or too old:$critic_missing
diff --git a/configure.ac b/configure.ac
index e983fd8faa..6cc10ede98 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1050,18 +1050,12 @@  else
 fi
 
 # Check for python3 if available, or else python.
-AC_CHECK_PROGS(PYTHON_PROG, python3 python,no)
-case "x$PYTHON_PROG" in
-xno|x|x:) PYTHON_PROG=no ;;
-*) ;;
-esac
-
-if test "x$PYTHON_PROG" = xno; then
-  aux_missing="$aux_missing python"
-else
-  PYTHON="$PYTHON_PROG -B"
-  AC_SUBST(PYTHON)
-fi
+AC_CHECK_PROG_VER(PYTHON_PROG, python3 python, --version,
+  [Python \([0-9][0-9.]*\)],
+  [3.[4-9]*|3.[1-9][0-9]*|[4-9].*|[1-9][0-9]*],
+  critic_missing="$critic_missing python")
+PYTHON="$PYTHON_PROG -B"
+AC_SUBST(PYTHON)
 
 test -n "$critic_missing" && AC_MSG_ERROR([
 *** These critical programs are missing or too old:$critic_missing
diff --git a/conform/Makefile b/conform/Makefile
index 71e58a46c8..a2bbe0fb24 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -120,9 +120,7 @@  linknamespace-symlists-base := $(foreach std,$(conformtest-standards),\
 					     symlist-$(std))
 linknamespace-symlists-tests := $(addprefix $(objpfx),\
 					    $(linknamespace-symlists-base))
-ifdef PYTHON
 tests-special += $(linknamespace-symlists-tests)
-endif
 
 linknamespace-symlist-stdlibs-base := $(foreach std,$(conformtest-standards),\
 						    symlist-stdlibs-$(std))
@@ -130,9 +128,7 @@  linknamespace-symlist-stdlibs-tests := \
 	$(addprefix $(objpfx),\
 		    $(linknamespace-symlist-stdlibs-base))
 
-ifdef PYTHON
 tests-special += $(linknamespace-symlist-stdlibs-tests)
-endif
 
 linknamespace-header-base := $(foreach std,\
 				       $(conformtest-standards),\
@@ -141,9 +137,7 @@  linknamespace-header-base := $(foreach std,\
 						 $(std)/$(h)/linknamespace.out))
 linknamespace-header-tests := $(addprefix $(objpfx),\
 					  $(linknamespace-header-base))
-ifdef PYTHON
 tests-special += $(linknamespace-header-tests)
-endif
 
 include ../Rules
 
diff --git a/manual/Makefile b/manual/Makefile
index 9c35c9d45f..5f6006dc09 100644
--- a/manual/Makefile
+++ b/manual/Makefile
@@ -172,7 +172,7 @@  include ../Rules
 install-data subdir_install: install
 # Generated files requiring python: libm-err.texi
 # Generated files requiring perl: summary.texi
-ifneq ($(if $(PYTHON),$(PERL),no),no)
+ifneq ($(PERL),no)
 ifneq ($(strip $(MAKEINFO)),:)
 install: $(inst_infodir)/libc.info
 	@if $(SHELL) -c '$(INSTALL_INFO) --version' >/dev/null 2>&1; then \
diff --git a/manual/install.texi b/manual/install.texi
index 08a39f57c9..c19002340b 100644
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -575,11 +575,11 @@  with any version of @code{sed}.  As of release time, @code{sed} version
 4.5 is the newest verified to work to build @theglibc{}.
 
 @item
-Python 2.7/3.4 or later
+Python 3.4 or later
 
-Python is required to build the @glibcadj{} manual and to run some
-tests.  As of release time, Python 3.6 is the newest verified to work
-for testing @theglibc{}.
+Python is required to build @theglibc{}.  As of release time, Python
+3.6 is the newest verified to work for building and testing
+@theglibc{}.
 
 @item PExpect 4.0
 
diff --git a/math/Makefile b/math/Makefile
index 750492b381..34db0215ef 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -255,7 +255,6 @@  tests += test-math-isinff test-math-iszero test-math-issignaling \
 	 test-math-iscanonical test-math-cxx11 test-math-iseqsig
 endif
 
-ifdef PYTHON
 libm-vec-tests = $(addprefix test-,$(libmvec-tests))
 libm-test-support = $(foreach t,$(test-types),libm-test-support-$(t))
 test-extras += $(libm-test-support)
@@ -351,9 +350,7 @@  $(libm-test-c-narrow-obj): $(objpfx)libm-test%.c: libm-test%.inc \
 						  auto-libm-test-out%
 	$(make-target-directory)
 	$(PYTHON) gen-libm-test.py -c $< -a auto-libm-test-out$* -C $@
-endif
 
-ifdef PYTHON
 tgmath3-macros = atan2 cbrt ceil copysign erf erfc exp2 expm1 fdim floor \
 		 fma fmax fmin fmod frexp hypot ilogb ldexp lgamma llrint \
 		 llround log10 log1p log2 logb lrint lround nearbyint \
@@ -380,7 +377,6 @@  tests-special += $(objpfx)test-tgmath3-macro-list.out
 $(objpfx)test-tgmath3-macro-list.out: gen-tgmath-tests.py
 	$(PYTHON) $< check-list $(tgmath3-macros) > $@; \
 	$(evaluate-test)
-endif
 
 libm-test-fast-math-cflags = -fno-builtin -D__FAST_MATH__ -DTEST_FAST_MATH
 libm-test-vec-cflags = $(libm-test-fast-math-cflags) -fno-inline \
@@ -476,7 +472,6 @@  $(objpfx)gen-libm-templates.stmp: Makefile
 $(foreach t, $(call type-foreach, $(gen-all-calls)), \
              $(objpfx)$(t).c): $(objpfx)gen-libm-templates.stmp
 
-ifdef PYTHON
 # This must come after the inclusion of sysdeps Makefiles via Rules.
 
 $(foreach t,$(libm-tests-normal),$(objpfx)$(t).c): $(objpfx)test-%.c:
@@ -637,11 +632,6 @@  regen-ulps: $(addprefix $(objpfx),$(libm-tests))
 	echo "Difference between the current baseline and the new baseline is:";\
 	diff -urN $(ulps-file) $(objpfx)NewUlps; \
 	echo "Copy $(objpfx)NewUlps to $(ulps-file) (relative to source)."
-else
-regen-ulps:
-	@echo "Automatic regeneration of ULPs requires python."; \
-	exit 1;
-endif
 
 # The generated sysd-rules file defines rules like this for sources
 # coming from sysdeps/ directories.  These rules find the generic sources.