sys-devel/flex: backport "config.h" fix too

We already have the patch to config.h/configure.ac backported
but we don't have the fix to actually *use* config.h everywhere,
and clearly from bug #705800 it wasn't sufficient to just backport
it (for reasons covered in the bug & upstream bug).

Bug: https://bugs.gentoo.org/628744
Bug: https://bugs.gentoo.org/705800
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 145 insertions, 0 deletions

diff --git a/sys-devel/flex/files/flex-2.6.4-implicit-func-decl.patch b/sys-devel/flex/files/flex-2.6.4-implicit-func-decl.patch
new file mode 100644
index 000000000000..1900ae0529b9
--- /dev/null
+++ b/sys-devel/flex/files/flex-2.6.4-implicit-func-decl.patch
@@ -0,0 +1,50 @@
+https://github.com/westes/flex/commit/4b5111d9772b5c160340ca96f08d30d7f6db5cda
+https://github.com/westes/flex/issues/436
+https://bugs.gentoo.org/705800
+https://developers.redhat.com/blog/2019/04/22/implicit-function-declarations-flexs-use-of-reallocarray
+
+From 4b5111d9772b5c160340ca96f08d30d7f6db5cda Mon Sep 17 00:00:00 2001
+From: Explorer09 <explorer09@gmail.com>
+Date: Mon, 4 Sep 2017 08:28:53 +0800
+Subject: [PATCH] scanner: Include flexdef.h at %top block of scan.l
+
+config.h may define macros that alter the API of the standard library
+funtions, and so it should be included before any other standard
+header, even before the skeleton's standard header inclusion.
+
+For example: config.h may #define _GNU_SOURCE that would expose the
+reallocarray() prototype from <stdlib.h> on glibc 2.26+ systems. If we
+include <stdlib.h> before config.h, reallocarray() would not be
+available for use in lex file since the second include doesn't help
+due to header guard.
+
+For now our config.h might `#define malloc rpl_malloc` -- this
+substitution must work before including stdlib.h, or else the compiler
+will complain about missing prototypes, and may result in incorrect
+code in scan.l (gcc warning: return makes pointer from integer without
+a cast [-Wint-conversion]).
+
+Fixes #247.
+--- a/src/scan.l
++++ b/src/scan.l
+@@ -1,5 +1,11 @@
+ /* scan.l - scanner for flex input -*-C-*- */
+ 
++%top{
++/* flexdef.h includes config.h, which may contain macros that alter the API */
++/* of libc functions. Must include first before any libc header. */
++#include "flexdef.h"
++}
++
+ %{
+ /*  Copyright (c) 1990 The Regents of the University of California. */
+ /*  All rights reserved. */
+@@ -32,7 +38,6 @@
+ /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
+ /*  PURPOSE. */
+ 
+-#include "flexdef.h"
+ #include "parse.h"
+ extern bool tablesverify, tablesext;
+ extern int trlcontxt; /* Set in  parse.y for each rule. */
+
diff --git a/sys-devel/flex/flex-2.6.4-r3.ebuild b/sys-devel/flex/flex-2.6.4-r3.ebuild
new file mode 100644
index 000000000000..1f1ebfe61893
--- /dev/null
+++ b/sys-devel/flex/flex-2.6.4-r3.ebuild
@@ -0,0 +1,95 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit flag-o-matic libtool multilib-minimal toolchain-funcs
+
+DESCRIPTION="The Fast Lexical Analyzer"
+HOMEPAGE="https://github.com/westes/flex"
+SRC_URI="https://github.com/westes/${PN}/releases/download/v${PV}/${P}.tar.gz"
+
+LICENSE="FLEX"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~x64-cygwin ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris"
+IUSE="nls static test"
+RESTRICT="!test? ( test )"
+
+# We want bison explicitly and not yacc in general, bug #381273
+RDEPEND="sys-devel/m4"
+BDEPEND="${RDEPEND}
+	nls? ( sys-devel/gettext )
+	test? ( sys-devel/bison )"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-2.6.4-libobjdir.patch
+	"${FILESDIR}"/${PN}-2.6.4-fix-build-with-glibc2.6+.patch
+	"${FILESDIR}"/${P}-implicit-func-decl.patch
+)
+
+src_prepare() {
+	default
+
+	# Disable running in the tests/ subdir as it has a bunch of built sources
+	# that cannot be made conditional (automake limitation). bug #568842
+	if ! use test ; then
+		sed -i \
+			-e '/^SUBDIRS =/,/^$/{/tests/d}' \
+			Makefile.in || die
+	fi
+
+	# Prefix always needs this
+	elibtoolize
+}
+
+src_configure() {
+	use static && append-ldflags -static
+
+	multilib-minimal_src_configure
+}
+
+multilib_src_configure() {
+	if tc-is-cross-compiler ; then
+		# Similar to workaround for procps:
+		# - bug #705800
+		# - https://sourceforge.net/p/psmisc/bugs/71/
+		# - https://lists.gnu.org/archive/html/autoconf/2011-04/msg00019.html
+		export ac_cv_func_malloc_0_nonnull=yes \
+			ac_cv_func_realloc_0_nonnull=yes
+	fi
+
+	# Do not install shared libs, #503522
+	ECONF_SOURCE="${S}" econf \
+		CC_FOR_BUILD="$(tc-getBUILD_CC)" \
+		--disable-shared \
+		$(use_enable nls)
+}
+
+multilib_src_compile() {
+	if multilib_is_native_abi; then
+		default
+	else
+		emake -C src -f Makefile -f - lib <<< 'lib: $(lib_LTLIBRARIES)'
+	fi
+}
+
+multilib_src_test() {
+	multilib_is_native_abi && emake check
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+		default
+	else
+		emake -C src DESTDIR="${D}" install-libLTLIBRARIES install-includeHEADERS
+	fi
+}
+
+multilib_src_install_all() {
+	einstalldocs
+	dodoc ONEWS
+	find "${ED}" -name '*.la' -type f -delete || die
+	rm "${ED}"/usr/share/doc/${PF}/COPYING || die
+
+	dosym flex /usr/bin/lex
+}