Introduced alignof support like the one for check_sizeof

6 files changed, 263 insertions, 0 deletions

diff --git a/tests/apis/check_xxx/xmake.lua b/tests/apis/check_xxx/xmake.lua
index 3643100ce..99745b1c7 100644
--- a/tests/apis/check_xxx/xmake.lua
+++ b/tests/apis/check_xxx/xmake.lua
@@ -21,6 +21,8 @@ target("foo")
     check_csnippets("INT_SIZE", 'printf("%d", sizeof(int)); return 0;', {output = true, number = true})
     check_sizeof("LONG_SIZE", "long")
     check_sizeof("STRING_SIZE", "std::string", {includes = "string"})
+    check_alignof("LONG_ALIGN", "long")
+    check_alignof("STRING_ALIGN", "std::string", {includes = "string"})
     configvar_check_bigendian("IS_BIG_ENDIAN")
     configvar_check_cincludes("HAS_STRING_AND_STDIO_H", {"string.h", "stdio.h"})
     configvar_check_ctypes("HAS_WCHAR_AND_FLOAT", {"wchar_t", "float"})
diff --git a/xmake/core/package/package.lua b/xmake/core/package/package.lua
index 95ee2a01b..81efad731 100644
--- a/xmake/core/package/package.lua
+++ b/xmake/core/package/package.lua
@@ -2679,6 +2679,19 @@ function _instance:check_sizeof(typename, opt)
     return sandbox_module.import("lib.detect.check_sizeof", {anonymous = true})(typename, opt)
 end
 
+-- check the aligment of type
+--
+-- @param typename  the typename
+-- @param opt       the argument options, e.g. {includes = "xxx.h", configs = {defines = ""}}
+--
+-- @return          the type alignment
+--
+function _instance:check_alignof(typename, opt)
+    opt = opt or {}
+    opt.target = self
+    return sandbox_module.import("lib.detect.check_alignof", {anonymous = true})(typename, opt)
+end
+
 -- check the given c snippets?
 --
 -- @param snippets  the snippets
diff --git a/xmake/core/project/target.lua b/xmake/core/project/target.lua
index 6861ba2e6..03891563b 100644
--- a/xmake/core/project/target.lua
+++ b/xmake/core/project/target.lua
@@ -2994,6 +2994,19 @@ function _instance:check_sizeof(typename, opt)
     return sandbox_module.import("lib.detect.check_sizeof", {anonymous = true})(typename, opt)
 end
 
+-- check the alignment of type
+--
+-- @param typename  the typename
+-- @param opt       the argument options, e.g. {includes = "xxx.h", configs = {defines = ""}}
+--
+-- @return          the type alignment
+--
+function _instance:check_alignof(typename, opt)
+    opt = opt or {}
+    opt.target = self:_checked_target()
+    return sandbox_module.import("lib.detect.check_alignof", {anonymous = true})(typename, opt)
+end
+
 -- check the endianness of compiler
 --
 -- @param opt       the argument options, e.g. {includes = "xxx.h", configs = {defines = ""}}
diff --git a/xmake/includes/check/check_alignof.lua b/xmake/includes/check/check_alignof.lua
new file mode 100644
index 000000000..1c97883c9
--- /dev/null
+++ b/xmake/includes/check/check_alignof.lua
@@ -0,0 +1,155 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2026, Xmake Open Source Community.
+--
+-- @author      karurochari
+-- @file        check_alignof.lua
+--
+
+-- check c alignof(type) add to macro definition support cross compile
+--
+-- from https://github.com/xmake-io/xmake/issues/4345
+--
+-- e.g.
+--
+-- check_alignof("ALIGNOF_LONG", "long") => ALIGNOF_LONG=4
+--
+-- configvar_check_alignof("ALIGNOF_LONG", "long") => #define ALIGNOF_LONG 4
+--
+local binary_match_pattern = 'INFO:align%[(%d+)%]'
+
+local check_alignof_template = [[
+#define ALIGN (alignof(${TYPE}))
+static char info_align[] =  {'I', 'N', 'F', 'O', ':', 'a','l','i','g','n','[',
+  ('0' + ((ALIGN / 10000)%10)),
+  ('0' + ((ALIGN / 1000)%10)),
+  ('0' + ((ALIGN / 100)%10)),
+  ('0' + ((ALIGN / 10)%10)),
+  ('0' +  (ALIGN    % 10)),
+  ']',
+  '\0'};
+
+int main(int argc, char *argv[]) {
+  int require = 0;
+  require += info_align[argc];
+  (void)argv;
+  return require;
+}]]
+
+function _binary_match(content)
+    local match = content:match(binary_match_pattern)
+    if match then
+        return match:ltrim("0")
+    end
+end
+
+function check_alignof(definition, typename, opt)
+    opt = opt or {}
+    if opt.number == nil then
+        opt.number = true
+    end
+    local optname = opt.name or ("__" .. definition)
+    local snippet = opt.snippet or ""
+    interp_save_scope()
+    option(optname)
+        set_showmenu(false)
+        add_cxxsnippets(definition, check_alignof_template:gsub('${TYPE}', typename), {binary_match = _binary_match})
+        if opt.links then
+            add_links(opt.links)
+        end
+        if opt.includes then
+            add_cxxincludes(opt.includes)
+        end
+        if opt.languages then
+            set_languages(opt.languages)
+        end
+        if opt.cflags then
+            add_cflags(opt.cflags)
+        end
+        if opt.cxflags then
+            add_cxflags(opt.cxflags)
+        end
+        if opt.defines then
+            add_defines(opt.defines)
+        end
+        if opt.warnings then
+            set_warnings(opt.warnings)
+        end
+        after_check(function (option)
+            if option:value() then
+                if opt.number then
+                    option:add("defines", definition .. "=" .. tonumber(option:value()))
+                elseif opt.quote == false then
+                    option:add("defines", definition .. "=" .. option:value())
+                else
+                    option:add("defines", definition .. "=\"" .. option:value() .. "\"")
+                end
+            end
+        end)
+    option_end()
+    interp_restore_scope()
+    add_options(optname)
+end
+
+
+function configvar_check_alignof(definition, typename, opt)
+    opt = opt or {}
+    if opt.number == nil then
+        opt.number = true
+    end
+    local optname = opt.name or ("__" .. definition)
+    local defname, defval = table.unpack(definition:split('='))
+    interp_save_scope()
+    option(optname)
+        set_showmenu(false)
+        add_cxxsnippets(definition, check_alignof_template:gsub('${TYPE}', typename), {binary_match = _binary_match})
+        if opt.default == nil then
+            set_configvar(defname, defval or 1, {quote = opt.quote})
+        end
+        if opt.links then
+            add_links(opt.links)
+        end
+        if opt.includes then
+            add_cxxincludes(opt.includes)
+        end
+        if opt.languages then
+            set_languages(opt.languages)
+        end
+        if opt.cflags then
+            add_cflags(opt.cflags)
+        end
+        if opt.cxflags then
+            add_cxflags(opt.cxflags)
+        end
+        if opt.defines then
+            add_defines(opt.defines)
+        end
+        if opt.warnings then
+            set_warnings(opt.warnings)
+        end
+        after_check(function (option)
+            if option:value() then
+                option:set("configvar", defname, opt.number and tonumber(option:value()) or option:value(), {quote = opt.quote})
+            end
+        end)
+    option_end()
+    interp_restore_scope()
+    if opt.default == nil then
+        add_options(optname)
+    else
+        set_configvar(defname, has_config(optname) and (defval or 1) or opt.default, {quote = true})
+    end
+end
+
diff --git a/xmake/includes/check/xmake.lua b/xmake/includes/check/xmake.lua
index 8d8b599ab..def264d85 100644
--- a/xmake/includes/check/xmake.lua
+++ b/xmake/includes/check/xmake.lua
@@ -33,4 +33,5 @@ includes("@builtin/check/check_links.lua")
 includes("@builtin/check/check_macros.lua")
 includes("@builtin/check/check_syslinks.lua")
 includes("@builtin/check/check_sizeof.lua")
+includes("@builtin/check/check_alignof.lua")
 includes("@builtin/check/check_bigendian.lua")
diff --git a/xmake/modules/lib/detect/check_alignof.lua b/xmake/modules/lib/detect/check_alignof.lua
new file mode 100644
index 000000000..d8b1561f4
--- /dev/null
+++ b/xmake/modules/lib/detect/check_alignof.lua
@@ -0,0 +1,79 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2026-present, Xmake Open Source Community.
+--
+-- @author      karurochari
+-- @file        check_alignof.lua
+--
+
+-- imports
+import("lib.detect.check_cxxsnippets")
+
+local binary_match_pattern = 'INFO:align%[(%d+)%]'
+
+local check_alignof_template = [[
+#define ALIGN (alignof(${TYPE}))
+static char info_align[] =  {'I', 'N', 'F', 'O', ':', 'a','l','i','g','n','[',
+  ('0' + ((ALIGN / 10000)%10)),
+  ('0' + ((ALIGN / 1000)%10)),
+  ('0' + ((ALIGN / 100)%10)),
+  ('0' + ((ALIGN / 10)%10)),
+  ('0' +  (ALIGN    % 10)),
+  ']',
+  '\0'};
+
+int main(int argc, char *argv[]) {
+  int require = 0;
+  require += info_align[argc];
+  (void)argv;
+  return require;
+}]]
+
+function _binary_match(content)
+    local match = content:match(binary_match_pattern)
+    if match then
+        return match:ltrim("0")
+    end
+end
+
+-- check the alignment of type
+--
+-- @param typename  the typename
+-- @param opt       the argument options
+--                  e.g.
+--                  { verbose = false, target = [target|option], includes = "stdio.h"
+--                  , configs = {defines = "xx", cxflags = ""}}
+--
+-- @return          the type alignment
+--
+-- @code
+-- local align = check_alignof("long")
+-- local align = check_alignof("std::string", {includes = "string"})
+-- @endcode
+--
+-- check the alignment of a C/C++ type
+--
+-- @param typename   the type name, e.g. "int", "size_t"
+-- @param opt        the options, e.g. {includes = {"stddef.h"}, target = target}
+-- @return           the type alignment in bytes, or -1
+--
+function main(typename, opt)
+    local snippets = check_alignof_template:gsub('${TYPE}', typename)
+    local ok, size = check_cxxsnippets(snippets, table.join(table.wrap(opt), {binary_match = _binary_match}))
+    if ok then
+        return size
+    end
+end
+