Feature/language

conan/tools/build/__init__.py

@@ -6,6 +6,8 @@
 from conan.tools.build.flags import cppstd_flag
 from conan.tools.build.cppstd import check_max_cppstd, check_min_cppstd, \
     valid_max_cppstd, valid_min_cppstd, default_cppstd, supported_cppstd
+from conan.tools.build.cstd import check_max_cstd, check_min_cstd, \
+    valid_max_cstd, valid_min_cstd, supported_cstd
 from conan.tools.build.cpu import build_jobs
 from conan.tools.build.cross_building import cross_building, can_run
 from conan.tools.build.stdcpp_library import stdcpp_library

conan/tools/build/cstd.py

@@ -0,0 +1,165 @@
+import operator
+
+from conan.errors import ConanInvalidConfiguration, ConanException
+from conans.model.version import Version
+
+
+def check_min_cstd(conanfile, cstd, gnu_extensions=False):
+    """ Check if current cstd fits the minimal version required.
+
+        In case the current cstd doesn't fit the minimal version required
+        by cstd, a ConanInvalidConfiguration exception will be raised.
+
+        1. If settings.compiler.cstd, the tool will use settings.compiler.cstd to compare
+        2. It not settings.compiler.cstd, the tool will use compiler to compare (reading the
+           default from cstd_default)
+        3. If not settings.compiler is present (not declared in settings) will raise because it
+           cannot compare.
+        4. If can not detect the default cstd for settings.compiler, a exception will be raised.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :param cstd: Minimal cstd version required
+    :param gnu_extensions: GNU extension is required (e.g gnu17)
+    """
+    _check_cstd(conanfile, cstd, operator.lt, gnu_extensions)
+
+
+def check_max_cstd(conanfile, cstd, gnu_extensions=False):
+    """ Check if current cstd fits the maximum version required.
+
+        In case the current cstd doesn't fit the maximum version required
+        by cstd, a ConanInvalidConfiguration exception will be raised.
+
+        1. If settings.compiler.cstd, the tool will use settings.compiler.cstd to compare
+        2. It not settings.compiler.cstd, the tool will use compiler to compare (reading the
+           default from cstd_default)
+        3. If not settings.compiler is present (not declared in settings) will raise because it
+           cannot compare.
+        4. If can not detect the default cstd for settings.compiler, a exception will be raised.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :param cstd: Maximum cstd version required
+    :param gnu_extensions: GNU extension is required (e.g gnu17)
+    """
+    _check_cstd(conanfile, cstd, operator.gt, gnu_extensions)
+
+
+def valid_min_cstd(conanfile, cstd, gnu_extensions=False):
+    """ Validate if current cstd fits the minimal version required.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :param cstd: Minimal cstd version required
+    :param gnu_extensions: GNU extension is required (e.g gnu17). This option ONLY works on Linux.
+    :return: True, if current cstd matches the required cstd version. Otherwise, False.
+    """
+    try:
+        check_min_cstd(conanfile, cstd, gnu_extensions)
+    except ConanInvalidConfiguration:
+        return False
+    return True
+
+
+def valid_max_cstd(conanfile, cstd, gnu_extensions=False):
+    """ Validate if current cstd fits the maximum version required.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :param cstd: Maximum cstd version required
+    :param gnu_extensions: GNU extension is required (e.g gnu17). This option ONLY works on Linux.
+    :return: True, if current cstd matches the required cstd version. Otherwise, False.
+    """
+    try:
+        check_max_cstd(conanfile, cstd, gnu_extensions)
+    except ConanInvalidConfiguration:
+        return False
+    return True
+
+
+def supported_cstd(conanfile, compiler=None, compiler_version=None):
+    """
+    Get a list of supported ``compiler.cstd`` for the "conanfile.settings.compiler" and
+    "conanfile.settings.compiler_version" or for the parameters "compiler" and "compiler_version"
+    if specified.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :param compiler: Name of the compiler e.g: gcc
+    :param compiler_version: Version of the compiler e.g: 12
+    :return: a list of supported ``cstd`` values.
+    """
+    compiler = compiler or conanfile.settings.get_safe("compiler")
+    compiler_version = compiler_version or conanfile.settings.get_safe("compiler.version")
+    if not compiler or not compiler_version:
+        raise ConanException("Called supported_cstd with no compiler or no compiler.version")
+
+    func = {"apple-clang": _apple_clang_supported_cstd,
+            "gcc": _gcc_supported_cstd,
+            "msvc": _msvc_supported_cstd,
+            "clang": _clang_supported_cstd,
+            }.get(compiler)
+    if func:
+        return func(Version(compiler_version))
+    return None
+
+
+def _check_cstd(conanfile, cstd, comparator, gnu_extensions):
+    """ Check if current cstd fits the version required according to a given comparator.
+
+        In case the current cstd doesn't fit the maximum version required
+        by cstd, a ConanInvalidConfiguration exception will be raised.
+
+        1. If settings.compiler.cstd, the tool will use settings.compiler.cstd to compare
+        2. It not settings.compiler.cstd, the tool will use compiler to compare (reading the
+           default from cstd_default)
+        3. If not settings.compiler is present (not declared in settings) will raise because it
+           cannot compare.
+        4. If can not detect the default cstd for settings.compiler, a exception will be raised.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :param cstd: Required cstd version.
+    :param comparator: Operator to use to compare the detected and the required cstd versions.
+    :param gnu_extensions: GNU extension is required (e.g gnu17)
+    """
+    if not str(cstd).isdigit():
+        raise ConanException("cstd parameter must be a number")
+
+    def compare(lhs, rhs, comp):
+        def extract_cpp_version(_cstd):
+            return str(_cstd).replace("gnu", "")
+
+        def add_millennium(_cstd):
+            return "19%s" % _cstd if _cstd == "99" else "20%s" % _cstd
+
+        lhs = add_millennium(extract_cpp_version(lhs))
+        rhs = add_millennium(extract_cpp_version(rhs))
+        return not comp(lhs, rhs)
+
+    current_cstd = conanfile.settings.get_safe("compiler.cstd")
+    if current_cstd is None:
+        raise ConanInvalidConfiguration("The compiler.cstd is not defined for this configuration")
+
+    if gnu_extensions and "gnu" not in current_cstd:
+        raise ConanInvalidConfiguration("The cstd GNU extension is required")
+
+    if not compare(current_cstd, cstd, comparator):
+        raise ConanInvalidConfiguration(
+            "Current cstd ({}) is {} than the required C standard ({}).".format(
+                current_cstd, "higher" if comparator == operator.gt else "lower", cstd))
+
+
+def _apple_clang_supported_cstd(version):
+    # TODO: Per-version support
+    return ["99", "gnu99", "11", "gnu11", "17", "gnu17", "23", "gnu23"]
+
+
+def _gcc_supported_cstd(version):
+    # TODO: Per-version support
+    return ["99", "gnu99", "11", "gnu11", "17", "gnu17", "23", "gnu23"]
+
+
+def _msvc_supported_cstd(version):
+    # TODO: Per-version support
+    return ["11", "17"]
+
+
+def _clang_supported_cstd(version):
+    # TODO: Per-version support
+    return ["99", "gnu99", "11", "gnu11", "17", "gnu17", "23", "gnu23"]

conan/tools/build/flags.py

@@ -482,3 +482,76 @@ def _cppstd_intel_cc(_, cppstd):
             "20": v20, "gnu20": vgnu20,
             "23": v23, "gnu23": vgnu23}.get(cppstd)
     return f'-std={flag}' if flag else None
+
+
+def cstd_flag(conanfile) -> str:
+    """
+    Returns flags specific to the C+standard based on the ``conanfile.settings.compiler``,
+    ``conanfile.settings.compiler.version`` and ``conanfile.settings.compiler.cstd``.
+
+    It also considers when using GNU extension in ``settings.compiler.cstd``, reflecting it in the
+    compiler flag. Currently, it supports GCC, Clang, AppleClang, MSVC, Intel, MCST-LCC.
+
+    In case there is no ``settings.compiler`` or ``settings.cstd`` in the profile, the result will
+    be an **empty string**.
+
+    :param conanfile: The current recipe object. Always use ``self``.
+    :return: ``str`` with the standard C flag used by the compiler.
+    """
+    compiler = conanfile.settings.get_safe("compiler")
+    compiler_version = conanfile.settings.get_safe("compiler.version")
+    cstd = conanfile.settings.get_safe("compiler.cstd")
+
+    if not compiler or not compiler_version or not cstd:
+        return ""
+
+    func = {"gcc": _cstd_gcc,
+            "clang": _cstd_clang,
+            "apple-clang": _cstd_apple_clang,
+            "msvc": _cstd_msvc}.get(compiler)
+    flag = None
+    if func:
+        flag = func(Version(compiler_version), str(cstd))
+    return flag
+
+
+def _cstd_gcc(gcc_version, cstd):
+    # TODO: Verify flags per version
+    flag = {"99": "c99",
+            "11": "c11",
+            "17": "c17",
+            "23": "c23"}.get(cstd, cstd)
+    return f'-std={flag}' if flag else None
+
+
+def _cstd_clang(gcc_version, cstd):
+    # TODO: Verify flags per version
+    flag = {"99": "c99",
+            "11": "c11",
+            "17": "c17",
+            "23": "c23"}.get(cstd, cstd)
+    return f'-std={flag}' if flag else None
+
+
+def _cstd_apple_clang(gcc_version, cstd):
+    # TODO: Verify flags per version
+    flag = {"99": "c99",
+            "11": "c11",
+            "17": "c17",
+            "23": "c23"}.get(cstd, cstd)
+    return f'-std={flag}' if flag else None
+
+
+def cstd_msvc_flag(visual_version, cstd):
+    if cstd == "17":
+        if visual_version >= "192":
+            return "c17"
+    elif cstd == "11":
+        if visual_version >= "192":
+            return "c11"
+    return None
+
+
+def _cstd_msvc(visual_version, cstd):
+    flag = cstd_msvc_flag(visual_version, cstd)
+    return f'/std:{flag}' if flag else None

conan/tools/cmake/toolchain/blocks.py

@@ -244,24 +244,39 @@ def context(self):
 
 class CppStdBlock(Block):
     template = textwrap.dedent("""
+        {% if cppstd %}
         message(STATUS "Conan toolchain: C++ Standard {{ cppstd }} with extensions {{ cppstd_extensions }}")
         set(CMAKE_CXX_STANDARD {{ cppstd }})
         set(CMAKE_CXX_EXTENSIONS {{ cppstd_extensions }})
         set(CMAKE_CXX_STANDARD_REQUIRED ON)
+        {% endif %}
+        {% if cstd %}
+        message(STATUS "Conan toolchain: C Standard {{ cstd }} with extensions {{ cstd_extensions }}")
+        set(CMAKE_C_STANDARD {{ cstd }})
+        set(CMAKE_C_EXTENSIONS {{ cstd_extensions }})
+        set(CMAKE_C_STANDARD_REQUIRED ON)
+        {% endif %}
         """)
 
     def context(self):
         compiler_cppstd = self._conanfile.settings.get_safe("compiler.cppstd")
-        if compiler_cppstd is None:
-            return None
-
-        if compiler_cppstd.startswith("gnu"):
-            cppstd = compiler_cppstd[3:]
-            cppstd_extensions = "ON"
-        else:
-            cppstd = compiler_cppstd
-            cppstd_extensions = "OFF"
-        return {"cppstd": cppstd, "cppstd_extensions": cppstd_extensions}
+        compiler_cstd = self._conanfile.settings.get_safe("compiler.cstd")
+        result = {}
+        if compiler_cppstd is not None:
+            if compiler_cppstd.startswith("gnu"):
+                result["cppstd"] = compiler_cppstd[3:]
+                result["cppstd_extensions"] = "ON"
+            else:
+                result["cppstd"] = compiler_cppstd
+                result["cppstd_extensions"] = "OFF"
+        if compiler_cstd is not None:
+            if compiler_cstd.startswith("gnu"):
+                result["cstd"] = compiler_cstd[3:]
+                result["cstd_extensions"] = "ON"
+            else:
+                result["cstd"] = compiler_cstd
+                result["cstd_extensions"] = "OFF"
+        return result or None
 
 
 class SharedLibBock(Block):

conan/tools/gnu/autotoolstoolchain.py

@@ -5,8 +5,7 @@
 from conan.tools.build import cmd_args_to_string, save_toolchain_args
 from conan.tools.build.cross_building import cross_building
 from conan.tools.build.flags import architecture_flag, build_type_flags, cppstd_flag, \
-    build_type_link_flags, \
-    libcxx_flags
+    build_type_link_flags, libcxx_flags, cstd_flag
 from conan.tools.env import Environment
 from conan.tools.gnu.get_gnu_triplet import _get_gnu_triplet
 from conan.tools.microsoft import VCVars, msvc_runtime_flag, unix_path, check_min_vs, is_msvc
@@ -49,6 +48,7 @@ def __init__(self, conanfile, namespace=None, prefix="/"):
         self.build_type_link_flags = build_type_link_flags(self._conanfile.settings)
 
         self.cppstd = cppstd_flag(self._conanfile)
+        self.cstd = cstd_flag(self._conanfile)
         self.arch_flag = architecture_flag(self._conanfile.settings)
         self.libcxx, self.gcc_cxx11_abi = libcxx_flags(self._conanfile)
         self.fpic = self._conanfile.options.get_safe("fPIC")
@@ -128,7 +128,7 @@ def cxxflags(self):
     @property
     def cflags(self):
         fpic = "-fPIC" if self.fpic else None
-        ret = [self.arch_flag, fpic, self.msvc_runtime_flag, self.sysroot_flag]
+        ret = [self.cstd, self.arch_flag, fpic, self.msvc_runtime_flag, self.sysroot_flag]
         apple_flags = [self.apple_isysroot_flag, self.apple_arch_flag, self.apple_min_version_flag]
         conf_flags = self._conanfile.conf.get("tools.build:cflags", default=[], check_type=list)
         vs_flag = self._add_msvc_flags(self.extra_cflags)

conan/tools/meson/helpers.py

@@ -2,7 +2,7 @@
 from conan.tools.build.flags import cppstd_msvc_flag
 from conans.model.options import _PackageOption
 
-__all__ = ["to_meson_machine", "to_meson_value", "to_cppstd_flag"]
+__all__ = ["to_meson_machine", "to_meson_value", "to_cppstd_flag", "to_cstd_flag"]
 
 # https://mesonbuild.com/Reference-tables.html#operating-system-names
 _meson_system_map = {
@@ -126,3 +126,16 @@ def to_cppstd_flag(compiler, compiler_version, cppstd):
         return 'v%s' % flag if flag else None
     else:
         return _cppstd_map.get(cppstd)
+
+
+def to_cstd_flag(cstd):
+    """ possible values
+    none, c89, c99, c11, c17, c18, c2x, c23, gnu89, gnu99, gnu11, gnu17, gnu18, gnu2x, gnu23
+    """
+    _cstd_map = {
+        '99': "c99",
+        '11': "c11",
+        '17': "c17",
+        '23': "c23",
+    }
+    return _cstd_map.get(cstd, cstd)

conan/tools/meson/toolchain.py

@@ -109,6 +109,9 @@ class MesonToolchain(object):
     {% if cpp_std %}
     cpp_std = '{{cpp_std}}'
     {% endif %}
+    {% if c_std %}
+    c_std = '{{c_std}}'
+    {% endif %}
     {% if backend %}
     backend = '{{backend}}'
     {% endif %}
@@ -188,6 +191,9 @@ def __init__(self, conanfile, backend=None, native=False):
         cppstd = self._conanfile.settings.get_safe("compiler.cppstd")
         self._cpp_std = to_cppstd_flag(compiler, compiler_version, cppstd)
 
+        cstd = self._conanfile.settings.get_safe("compiler.cstd")
+        self._c_std = to_cstd_flag(cstd)
+
         self._b_vscrt = None
         if compiler in ("msvc", "clang"):
             vscrt = msvc_runtime_flag(self._conanfile)
@@ -488,6 +494,7 @@ def _context(self):
             "b_ndebug": to_meson_value(self._b_ndebug),  # boolean as string
             # https://mesonbuild.com/Builtin-options.html#compiler-options
             "cpp_std": self._cpp_std,
+            "c_std": self._c_std,
             "c_args": to_meson_value(self._filter_list_empty_fields(self.c_args)),
             "c_link_args": to_meson_value(self._filter_list_empty_fields(self.c_link_args)),
             "cpp_args": to_meson_value(self._filter_list_empty_fields(self.cpp_args)),