[3.13] gh-113565: Improve and harden detection of curses dependencies (GH-119816) (#121202)

1. Use pkg-config to check for ncursesw/panelw. If that fails, use
   pkg-config to check for ncurses/panel.
2. Regardless of pkg-config output, search for curses/panel headers, so
   we're sure we have all defines in pyconfig.h.
3. Regardless of pkg-config output, check if libncurses or libncursesw
   contains the 'initscr' symbol; if it does _and_ pkg-config failed
   earlier, add the resulting -llib linker option to CURSES_LIBS.
   Ditto for 'update_panels' and PANEL_LIBS.
4. Wrap the rest of the checks with WITH_SAVE_ENV and make sure we're
   using updated LIBS and CPPFLAGS for those.

Add the PY_CHECK_CURSES convenience macro.
(cherry picked from commit f80376b129)

Co-authored-by: Erlend E. Aasland <erlend@python.org>

Include/py_curses.h

@@ -36,13 +36,21 @@
 #define NCURSES_OPAQUE 0
 #endif
 
-#ifdef HAVE_NCURSES_H
+#if defined(HAVE_NCURSESW_NCURSES_H)
-#include <ncurses.h>
+#  include <ncursesw/ncurses.h>
-#else
+#elif defined(HAVE_NCURSESW_CURSES_H)
-#include <curses.h>
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
 #endif
 
-#ifdef HAVE_NCURSES_H
+#ifdef NCURSES_VERSION
 /* configure was checking <curses.h>, but we will
    use <ncurses.h>, which has some or all these features. */
 #if !defined(WINDOW_HAS_FLAGS) && \

Misc/NEWS.d/next/Build/2024-06-02-13-23-26.gh-issue-113565.8xBlId.rst

@@ -0,0 +1,2 @@
+Improve :mod:`curses` and :mod:`curses.panel` dependency checks in
+:program:`configure`.

Modules/_curses_panel.c

@@ -19,7 +19,13 @@ static const char PyCursesVersion[] = "2.1";
 
 #include "py_curses.h"
 
-#include <panel.h>
+#if defined(HAVE_NCURSESW_PANEL_H)
+#  include <ncursesw/panel.h>
+#elif defined(HAVE_NCURSES_PANEL_H)
+#  include <ncurses/panel.h>
+#elif defined(HAVE_PANEL_H)
+#  include <panel.h>
+#endif
 
 typedef struct {
     PyObject *PyCursesError;

Modules/_cursesmodule.c

@@ -128,7 +128,7 @@ static const char PyCursesVersion[] = "2.2";
 #include <langinfo.h>
 #endif
 
-#if !defined(HAVE_NCURSES_H) && (defined(sgi) || defined(__sun) || defined(SCO5))
+#if !defined(NCURSES_VERSION) && (defined(sgi) || defined(__sun) || defined(SCO5))
 #define STRICT_SYSV_CURSES       /* Don't use ncurses extensions */
 typedef chtype attr_t;           /* No attr_t type is available */
 #endif

configure.ac

@@ -6653,55 +6653,88 @@ then
   [Define if year with century should be normalized for strftime.])
 fi
 
-dnl check for ncurses/ncursesw and panel/panelw
+dnl check for ncursesw/ncurses and panelw/panel
 dnl NOTE: old curses is not detected.
-dnl have_curses=[no, ncursesw, ncurses]
+dnl have_curses=[no, yes]
-dnl have_panel=[no, panelw, panel]
+dnl have_panel=[no, yes]
 have_curses=no
 have_panel=no
 
-AH_TEMPLATE([HAVE_NCURSESW], [Define to 1 if you have the `ncursesw' library.])
+dnl PY_CHECK_CURSES(LIBCURSES, LIBPANEL)
-AC_CHECK_HEADERS([curses.h ncurses.h])
+dnl Sets 'have_curses' and 'have_panel'.
+dnl For the PKG_CHECK_MODULES() calls, we can safely reuse the first variable
+dnl here, since we're only calling the macro a second time if the first call
+dnl fails.
+AC_DEFUN([PY_CHECK_CURSES], [dnl
+AS_VAR_PUSHDEF([curses_var], [m4_toupper([$1])])
+AS_VAR_PUSHDEF([panel_var], [m4_toupper([$2])])
+PKG_CHECK_MODULES([CURSES], [$1],
+  [AC_DEFINE([HAVE_]curses_var, [1], [Define if you have the '$1' library])
+   AS_VAR_SET([have_curses], [yes])
+   PKG_CHECK_MODULES([PANEL], [$2],
+    [AC_DEFINE([HAVE_]panel_var, [1], [Define if you have the '$2' library])
+     AS_VAR_SET([have_panel], [yes])],
+    [AS_VAR_SET([have_panel], [no])])],
+  [AS_VAR_SET([have_curses], [no])])
+AS_VAR_POPDEF([curses_var])
+AS_VAR_POPDEF([panel_var])])
 
-AS_VAR_IF([ac_cv_header_ncurses_h], [yes], [
+# Check for ncursesw/panelw first. If that fails, try ncurses/panel.
-  if test "$ac_sys_system" != "Darwin"; then
+PY_CHECK_CURSES([ncursesw], [panelw])
-    dnl On macOS, there is no separate /usr/lib/libncursesw nor libpanelw.
+AS_VAR_IF([have_curses], [no],
-    PKG_CHECK_MODULES([CURSES], [ncursesw], [
+          [PY_CHECK_CURSES([ncurses], [panel])])
-      AC_DEFINE([HAVE_NCURSESW], [1])
-      have_curses=ncursesw
-    ], [
-      WITH_SAVE_ENV([
-        AC_CHECK_LIB([ncursesw], [initscr], [
-          AC_DEFINE([HAVE_NCURSESW], [1])
-          have_curses=ncursesw
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
-          CURSES_LIBS=${CURSES_LIBS-"-lncursesw"}
-        ])
-      ])
-    ])
-  fi
 
-  AS_VAR_IF([have_curses], [no], [
+WITH_SAVE_ENV([
-    PKG_CHECK_MODULES([CURSES], [ncurses], [
+  # Make sure we've got the header defines.
-      have_curses=ncurses
+  AS_VAR_APPEND([CPPFLAGS], [" $CURSES_CFLAGS $PANEL_CFLAGS"])
-    ], [
+  AC_CHECK_HEADERS(m4_normalize([
-      WITH_SAVE_ENV([
+    ncursesw/curses.h ncursesw/ncurses.h ncursesw/panel.h
-        AC_CHECK_LIB([ncurses], [initscr], [
+    ncurses/curses.h ncurses/ncurses.h ncurses/panel.h
-          have_curses=ncurses
+    curses.h ncurses.h panel.h
-          CURSES_CFLAGS=${CURSES_CFLAGS-""}
+  ]))
-          CURSES_LIBS=${CURSES_LIBS-"-lncurses"}
-        ])
-      ])
-    ])
-  ])
 
-])dnl ac_cv_header_ncurses_h = yes
+  # Check that we're able to link with crucial curses/panel functions. This
+  # also serves as a fallback in case pkg-config failed.
+  AS_VAR_APPEND([LIBS], [" $CURSES_LIBS $PANEL_LIBS"])
+  AC_SEARCH_LIBS([initscr], [ncursesw ncurses],
+    [AS_VAR_IF([have_curses], [no],
+      [AS_VAR_SET([have_curses], [yes])
+       CURSES_LIBS=${CURSES_LIBS-"$ac_cv_search_initscr"}])],
+    [AS_VAR_SET([have_curses], [no])])
+  AC_SEARCH_LIBS([update_panels], [panelw panel],
+    [AS_VAR_IF([have_panel], [no],
+      [AS_VAR_SET([have_panel], [yes])
+       PANEL_LIBS=${PANEL_LIBS-"$ac_cv_search_update_panels"}])],
+    [AS_VAR_SET([have_panel], [no])])
 
+dnl Issue #25720: ncurses has introduced the NCURSES_OPAQUE symbol making opaque
+dnl structs since version 5.7.  If the macro is defined as zero before including
+dnl [n]curses.h, ncurses will expose fields of the structs regardless of the
+dnl configuration.
+AC_DEFUN([_CURSES_INCLUDES],dnl
+[
+#define NCURSES_OPAQUE 0
+#if defined(HAVE_NCURSESW_NCURSES_H)
+#  include <ncursesw/ncurses.h>
+#elif defined(HAVE_NCURSESW_CURSES_H)
+#  include <ncursesw/curses.h>
+#elif defined(HAVE_NCURSES_NCURSES_H)
+#  include <ncurses/ncurses.h>
+#elif defined(HAVE_NCURSES_CURSES_H)
+#  include <ncurses/curses.h>
+#elif defined(HAVE_NCURSES_H)
+#  include <ncurses.h>
+#elif defined(HAVE_CURSES_H)
+#  include <curses.h>
+#endif
+])
+
+AS_IF([test "have_curses" != "no"], [
 dnl remove _XOPEN_SOURCE macro from curses cflags. pyconfig.h sets
 dnl the macro to 700.
 CURSES_CFLAGS=$(echo $CURSES_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
 
-if test "$have_curses" != no -a "$ac_sys_system" = "Darwin"; then
+AS_VAR_IF([ac_sys_system], [Darwin], [
   dnl On macOS, there is no separate /usr/lib/libncursesw nor libpanelw.
   dnl System-supplied ncurses combines libncurses/libpanel and supports wide
   dnl characters, so we can use it like ncursesw.
@@ -6711,82 +6744,17 @@ if test "$have_curses" != no -a "$ac_sys_system" = "Darwin"; then
   dnl _XOPEN_SOURCE_EXTENDED here for ncurses wide char support.
 
   AS_VAR_APPEND([CURSES_CFLAGS], [" -D_XOPEN_SOURCE_EXTENDED=1"])
-  AC_DEFINE([HAVE_NCURSESW], [1])
-fi
-
-dnl TODO: detect "curses" and special cases tinfo, terminfo, or termcap
-
-AC_MSG_CHECKING([curses module flags])
-AS_VAR_IF([have_curses], [no], [
-  AC_MSG_RESULT([no])
-], [
-  AC_MSG_RESULT([$have_curses (CFLAGS: $CURSES_CFLAGS, LIBS: $CURSES_LIBS)])
 ])
 
-dnl check for ncurses' panel/panelw library
-AC_CHECK_HEADERS([panel.h])
-
-AS_VAR_IF([ac_cv_header_panel_h], [yes], [
-
-  if test "$ac_sys_system" != "Darwin"; then
-    dnl On macOS, there is no separate /usr/lib/libncursesw nor libpanelw.
-    AS_VAR_IF([have_curses], [ncursesw], [
-      PKG_CHECK_MODULES([PANEL], [panelw], [
-        have_panel=panelw
-      ], [
-        WITH_SAVE_ENV([
-          AC_CHECK_LIB([panelw], [update_panels], [
-            have_panel=panelw
-            PANEL_CFLAGS=${PANEL_CFLAGS-""}
-            PANEL_LIBS=${PANEL_LIBS-"-lpanelw"}
-          ])
-        ])
-      ])
-    ])
-  fi
-
-  AS_VAR_IF([have_curses], [ncurses], [
-    PKG_CHECK_MODULES([PANEL], [panel], [
-      have_panel=panel
-    ], [
-      WITH_SAVE_ENV([
-        AC_CHECK_LIB([panel], [update_panels], [
-          have_panel=panel
-          PANEL_CFLAGS=${PANEL_CFLAGS-""}
-          PANEL_LIBS=${PANEL_LIBS-"-lpanel"}
-        ])
-      ])
-    ])
-  ])
-
-])dnl ac_cv_header_panel_h = yes
-
 dnl pyconfig.h defines _XOPEN_SOURCE=700
 PANEL_CFLAGS=$(echo $PANEL_CFLAGS | sed 's/-D_XOPEN_SOURCE=600//g')
 
-AC_MSG_CHECKING([panel flags])
-AS_VAR_IF([have_panel], [no], [
-  AC_MSG_RESULT([no])
-], [
-  AC_MSG_RESULT([$have_panel (CFLAGS: $PANEL_CFLAGS, LIBS: $PANEL_LIBS)])
-])
-
-# first curses header check
-ac_save_cppflags="$CPPFLAGS"
-if test "$cross_compiling" = no; then
-  CPPFLAGS="$CPPFLAGS -I/usr/include/ncursesw"
-fi
-
 # On Solaris, term.h requires curses.h
-AC_CHECK_HEADERS([term.h], [], [], [
+AC_CHECK_HEADERS([term.h], [], [], _CURSES_INCLUDES)
-#ifdef HAVE_CURSES_H
-#include <curses.h>
-#endif
-])
 
 # On HP/UX 11.0, mvwdelch is a block with a return statement
 AC_CACHE_CHECK([whether mvwdelch is an expression], [ac_cv_mvwdelch_is_expression],
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <curses.h>]], [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(_CURSES_INCLUDES, [[
   int rtn;
   rtn = mvwdelch(0,0,0);
 ]])],
@@ -6799,15 +6767,8 @@ then
   [Define if mvwdelch in curses.h is an expression.])
 fi
 
-# Issue #25720: ncurses has introduced the NCURSES_OPAQUE symbol making opaque
-# structs since version 5.7.  If the macro is defined as zero before including
-# [n]curses.h, ncurses will expose fields of the structs regardless of the
-# configuration.
 AC_CACHE_CHECK([whether WINDOW has _flags], [ac_cv_window_has_flags],
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(_CURSES_INCLUDES, [[
-  #define NCURSES_OPAQUE 0
-  #include <curses.h>
-]], [[
   WINDOW *w;
   w->_flags = 0;
 ]])],
@@ -6829,11 +6790,7 @@ AC_DEFUN([PY_CHECK_CURSES_FUNC],
     [for curses function $1],
     [py_var],
     [AC_COMPILE_IFELSE(
-      [AC_LANG_PROGRAM(
+      [AC_LANG_PROGRAM(_CURSES_INCLUDES, [
-        [
-        #define NCURSES_OPAQUE 0
-        #include <curses.h>
-        ], [
         #ifndef $1
         void *x=$1
         #endif
@@ -6861,6 +6818,8 @@ PY_CHECK_CURSES_FUNC([has_key])
 PY_CHECK_CURSES_FUNC([typeahead])
 PY_CHECK_CURSES_FUNC([use_env])
 CPPFLAGS=$ac_save_cppflags
+])dnl have_curses != no
+])dnl save env
 
 AC_MSG_NOTICE([checking for device files])
 
@@ -7778,11 +7737,11 @@ PY_STDLIB_MOD([_ctypes],
   [], [test "$have_libffi" = yes],
   [$NO_STRICT_OVERFLOW_CFLAGS $LIBFFI_CFLAGS], [$LIBFFI_LIBS])
 PY_STDLIB_MOD([_curses],
-  [], [test "$have_curses" != "no"],
+  [], [test "$have_curses" = "yes"],
   [$CURSES_CFLAGS], [$CURSES_LIBS]
 )
 PY_STDLIB_MOD([_curses_panel],
-  [], [test "$have_panel" != "no"],
+  [], [test "$have_curses" = "yes" && test "$have_panel" = "yes"],
   [$PANEL_CFLAGS $CURSES_CFLAGS], [$PANEL_LIBS $CURSES_LIBS]
 )
 PY_STDLIB_MOD([_decimal],

pyconfig.h.in

@@ -829,12 +829,33 @@
 /* Define to 1 if you have the `nanosleep' function. */
 #undef HAVE_NANOSLEEP
 
-/* Define to 1 if you have the `ncursesw' library. */
+/* Define if you have the 'ncurses' library */
+#undef HAVE_NCURSES
+
+/* Define if you have the 'ncursesw' library */
 #undef HAVE_NCURSESW
 
+/* Define to 1 if you have the <ncursesw/curses.h> header file. */
+#undef HAVE_NCURSESW_CURSES_H
+
+/* Define to 1 if you have the <ncursesw/ncurses.h> header file. */
+#undef HAVE_NCURSESW_NCURSES_H
+
+/* Define to 1 if you have the <ncursesw/panel.h> header file. */
+#undef HAVE_NCURSESW_PANEL_H
+
+/* Define to 1 if you have the <ncurses/curses.h> header file. */
+#undef HAVE_NCURSES_CURSES_H
+
 /* Define to 1 if you have the <ncurses.h> header file. */
 #undef HAVE_NCURSES_H
 
+/* Define to 1 if you have the <ncurses/ncurses.h> header file. */
+#undef HAVE_NCURSES_NCURSES_H
+
+/* Define to 1 if you have the <ncurses/panel.h> header file. */
+#undef HAVE_NCURSES_PANEL_H
+
 /* Define to 1 if you have the <ndbm.h> header file. */
 #undef HAVE_NDBM_H
 
@@ -878,6 +899,12 @@
 /* Define to 1 if you have the `openpty' function. */
 #undef HAVE_OPENPTY
 
+/* Define if you have the 'panel' library */
+#undef HAVE_PANEL
+
+/* Define if you have the 'panelw' library */
+#undef HAVE_PANELW
+
 /* Define to 1 if you have the <panel.h> header file. */
 #undef HAVE_PANEL_H