cmake.eclass: Provide a list of CMake files unsupported with CMake 4

Instead of only eqawarning that there is *some* file with a too low
cmake_minimum_required version, print a list of all the CMakeLists.txt
found to be unsupported, and the detected version next to it.

- _CMAKE_MINREQVER_CMAKE305 is either empty (package "passed") or
  contains a list of <file>:<version> tuples to print as eqawarn message
  This replaces _CMAKE_MINREQVER_UNSUPPORTED
- Rename _cmake4_callout() -> _cmake_minreqver-info()
  Provide upstream link with list of CMake policy changes per release
- Prepare for upcoming additional cmake_minimum_version checks
- Rename _cmake_minreqver-lt() -> _cmake_minreqver-check()
  Function now optionally takes one or two args:
  <file>: runs all version checks over <file>
  <file> <version>: only check <version> against <file>

Closes: https://bugs.gentoo.org/951350
Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>

1 files changed, 64 insertions, 35 deletions

diff --git a/eclass/cmake.eclass b/eclass/cmake.eclass
index e132b0b53deb..ebc78a333eef 100644
--- a/eclass/cmake.eclass
+++ b/eclass/cmake.eclass
@@ -124,11 +124,13 @@ fi
 # If set, skip detection of CMakeLists.txt unsupported in CMake 4 in case of
 # false positives (e.g. unused outdated bundled libs).
 
-# @ECLASS_VARIABLE: _CMAKE_MINREQVER_UNSUPPORTED
+# @ECLASS_VARIABLE: _CMAKE_MINREQVER_CMAKE305
 # @DEFAULT_UNSET
 # @DESCRIPTION:
-# Internal status set by _cmake_minreqver-lt(); is true if an unsupported
-# cmake_minimum_required value was detected.
+# Internal array containing <file>:<version> tuples detected by
+# _cmake_minreqver-check() for any CMakeLists.txt with cmake_minimum_required
+# version lower than 3.5.
+_CMAKE_MINREQVER_CMAKE305=()
 
 # @ECLASS_VARIABLE: CMAKE_QA_SRC_DIR_READONLY
 # @USER_VARIABLE
@@ -330,25 +332,69 @@ _cmake_check_build_dir() {
 	mkdir -p "${BUILD_DIR}" || die
 }
 
-# @FUNCTION: _cmake_minreqver-lt
-# @USAGE: <lt-version> <path>
+# @FUNCTION: _cmake_minreqver-check
+# @USAGE: <path> or <path> <lt-version>
 # @INTERNAL
 # @DESCRIPTION:
-# Internal function for detecting occurrence of lower-than-specified
-# <lt-version> in cmake_minimum_required of a given CMake file <path>.
+# Internal function for flagging any deprecated or unsupported
+# cmake_minimum_required version in a given CMake file <path>.
+# If <lt-version> is specified as second arg, only check against that value.
 # Returns 0 if the regex matched (a lower-than-specified version found).
-_cmake_minreqver-lt() {
+_cmake_minreqver-check() {
 	local ver chk=1
+	if [[ "$#" == 2 ]]; then
+		local file="${1}"
+		local lt_version="${2}"
+	elif [[ "$#" == 1 ]]; then
+		local file="${1}"
+	else
+		die "${FUNCNAME[0]} must be passed either one or two arguments"
+	fi
 	ver=$(sed -ne "/^\s*cmake_minimum_required/I{s/.*\(\.\.\.*\|\s\)\([0-9][0-9.]*\)\([)]\|\s\).*$/\2/p;q}" \
-		"${2}" 2>/dev/null \
+		"${file}" 2>/dev/null \
 	)
-	if [[ -n ${ver} ]] && ver_test "${ver}" -lt "${1}"; then
-		_CMAKE_MINREQVER_UNSUPPORTED=true
-		chk=0
+	if [[ -z ${ver} ]]; then
+		return 1 # no cmake_minimum_required found
+	fi
+	if [[ -n ${lt_version} ]]; then
+		chk=$(ver_test "${ver}" -lt "${lt_version}")
+	else
+		if ver_test "${ver}" -lt "3.5"; then
+			_CMAKE_MINREQVER_CMAKE305+=( "${file}":"${ver}" )
+			chk=0
+		fi
 	fi
 	return ${chk}
 }
 
+# @FUNCTION: _cmake_minreqver-info
+# @INTERNAL
+# @DESCRIPTION:
+# QA Notice and file listing for any CMakeLists.txt file unsupported w/ CMake-4.
+_cmake_minreqver-info() {
+	local info
+	if [[ -n ${_CMAKE_MINREQVER_CMAKE305[@]} ]]; then
+		eqawarn "QA Notice: Compatibility with CMake < 3.5 has been removed from CMake 4,"
+		eqawarn "${CATEGORY}/${PN} will fail to build w/o a fix."
+		eqawarn "See also tracker bug #951350; check existing bug or file a new one for"
+		eqawarn "this package, and take it upstream."
+		eqawarn
+		eqawarn "The following CMakeLists.txt files are causing errors:"
+		for info in ${_CMAKE_MINREQVER_CMAKE305[*]}; do
+			eqawarn "  ${info}"
+		done
+		eqawarn
+		if has_version -b ">=dev-build/cmake-4"; then
+			eqawarn "CMake 4 detected; building with -DCMAKE_POLICY_VERSION_MINIMUM=3.5"
+			eqawarn "This is merely a workaround and *not* a permanent fix."
+			eqawarn
+		fi
+		eqawarn "An upstreamable patch should take any resulting CMake policy changes"
+		eqawarn "into account. See also:"
+		eqawarn "  https://cmake.org/cmake/help/latest/manual/cmake-policies.7.html"
+	fi
+}
+
 # @FUNCTION: _cmake_modify-cmakelists
 # @INTERNAL
 # @DESCRIPTION:
@@ -376,8 +422,8 @@ _cmake_modify-cmakelists() {
 			done
 		fi
 		# Detect unsupported minimum CMake versions unless CMAKE_QA_COMPAT_SKIP is set
-		if [[ -z ${_CMAKE_MINREQVER_UNSUPPORTED} ]] && ! [[ ${CMAKE_QA_COMPAT_SKIP} ]]; then
-			_cmake_minreqver-lt "3.5" "${file}"
+		if ! [[ ${CMAKE_QA_COMPAT_SKIP} ]]; then
+			_cmake_minreqver-check "${file#"${CMAKE_USE_DIR}/"}"
 		fi
 	done < <(find "${CMAKE_USE_DIR}" -type f -iname "CMakeLists.txt" -print0 || die)
 
@@ -397,23 +443,6 @@ _cmake_modify-cmakelists() {
 	_EOF_
 }
 
-# @FUNCTION: _cmake4_callout
-# @INTERNAL
-# @DESCRIPTION:
-# QA notice printout for build systems unsupported w/ CMake-4.
-_cmake4_callout() {
-	if [[ ${_CMAKE_MINREQVER_UNSUPPORTED} ]]; then
-		eqawarn "QA Notice: Compatibility with CMake < 3.5 has been removed from CMake 4,"
-		eqawarn "${CATEGORY}/${PN} will fail to build w/o a fix."
-		eqawarn "See also tracker bug #951350; check existing bug or file a new one for"
-		eqawarn "this package, and take it upstream."
-		if has_version -b ">=dev-build/cmake-4"; then
-			eqawarn "CMake 4 detected; building with -DCMAKE_POLICY_VERSION_MINIMUM=3.5"
-			eqawarn "This is merely a workaround and *not* a permanent fix."
-		fi
-	fi
-}
-
 # @FUNCTION: cmake_prepare
 # @DESCRIPTION:
 # Check existence of and sanitise CMake files, then make ${CMAKE_USE_DIR}
@@ -445,7 +474,7 @@ cmake_prepare() {
 
 	# Remove dangerous things.
 	_cmake_modify-cmakelists
-	_cmake4_callout
+	_cmake_minreqver-info
 
 	# Make ${CMAKE_USE_DIR} read-only in order to detect broken build systems
 	if [[ ${CMAKE_QA_SRC_DIR_READONLY} && ! ${CMAKE_IN_SOURCE_BUILD} ]]; then
@@ -486,7 +515,7 @@ cmake_src_prepare() {
 				find "${S}" -name "${name}.cmake" -exec rm -v {} + || die
 			done
 			_cmake_modify-cmakelists # Remove dangerous things.
-			_cmake4_callout
+			_cmake_minreqver-info
 		popd > /dev/null || die
 		# Make ${S} read-only in order to detect broken build systems
 		if [[ ${CMAKE_QA_SRC_DIR_READONLY} && ! ${CMAKE_IN_SOURCE_BUILD} ]]; then
@@ -719,7 +748,7 @@ cmake_src_configure() {
 		cmakeargs+=( -C "${CMAKE_EXTRA_CACHE_FILE}" )
 	fi
 
-	if [[ ${_CMAKE_MINREQVER_UNSUPPORTED} ]] && has_version -b ">=dev-build/cmake-4"; then
+	if [[ -n ${_CMAKE_MINREQVER_CMAKE305[@]} ]] && has_version -b ">=dev-build/cmake-4"; then
 		cmakeargs+=( -DCMAKE_POLICY_VERSION_MINIMUM=3.5 )
 	fi
 
@@ -855,7 +884,7 @@ cmake_src_install() {
 	while read -d '' -r file ; do
 		# Detect unsupported minimum CMake versions unless CMAKE_QA_COMPAT_SKIP is set
 		if ! [[ ${CMAKE_QA_COMPAT_SKIP} ]]; then
-			_cmake_minreqver-lt "3.5" "${file}" && files+=( "${file#"${D}"}" )
+			_cmake_minreqver-check "3.5" "${file}" && files+=( "${file#"${D}"}" )
 		fi
 	done < <(find "${D}" -type f -iname "*.cmake" -print0 || die)
 	if [[ ${#files[*]} -gt 0 ]]; then