diff --git a/tests/auxiliary/minicore.rs b/tests/auxiliary/minicore.rs
index a68552175c318..663c0abaae80c 100644
--- a/tests/auxiliary/minicore.rs
+++ b/tests/auxiliary/minicore.rs
@@ -17,9 +17,64 @@
 #![feature(no_core, lang_items, rustc_attrs, decl_macro, naked_functions, f16, f128)]
 #![allow(unused, improper_ctypes_definitions, internal_features)]
 #![feature(asm_experimental_arch)]
+#![feature(intrinsics)]
 #![no_std]
 #![no_core]
 
+/// Vendored from the 'cfg_if' crate
+
+macro_rules! cfg_if {
+    // match if/else chains with a final `else`
+    (
+        $(
+            if #[cfg( $i_meta:meta )] { $( $i_tokens:tt )* }
+        ) else+
+        else { $( $e_tokens:tt )* }
+    ) => {
+        cfg_if! {
+            @__items () ;
+            $(
+                (( $i_meta ) ( $( $i_tokens )* )) ,
+            )+
+            (() ( $( $e_tokens )* )) ,
+        }
+    };
+
+    // Internal and recursive macro to emit all the items
+    //
+    // Collects all the previous cfgs in a list at the beginning, so they can be
+    // negated. After the semicolon is all the remaining items.
+    (@__items ( $( $_:meta , )* ) ; ) => {};
+    (
+        @__items ( $( $no:meta , )* ) ;
+        (( $( $yes:meta )? ) ( $( $tokens:tt )* )) ,
+        $( $rest:tt , )*
+    ) => {
+        // Emit all items within one block, applying an appropriate #[cfg]. The
+        // #[cfg] will require all `$yes` matchers specified and must also negate
+        // all previous matchers.
+        #[cfg(all(
+            $( $yes , )?
+            not(any( $( $no ),* ))
+        ))]
+        cfg_if! { @__identity $( $tokens )* }
+
+        // Recurse to emit all other items in `$rest`, and when we do so add all
+        // our `$yes` matchers to the list of `$no` matchers as future emissions
+        // will have to negate everything we just matched as well.
+        cfg_if! {
+            @__items ( $( $no , )* $( $yes , )? ) ;
+            $( $rest , )*
+        }
+    };
+
+    // Internal macro to make __apply work out right for different match types,
+    // because of how macros match/expand stuff.
+    (@__identity $( $tokens:tt )* ) => {
+        $( $tokens )*
+    };
+}
+
 // `core` has some exotic `marker_impls!` macro for handling the with-generics cases, but for our
 // purposes, just use a simple macro_rules macro.
 macro_rules! impl_marker_trait {
@@ -101,6 +156,7 @@ macro_rules! concat {
         /* compiler built-in */
     };
 }
+
 #[rustc_builtin_macro]
 #[macro_export]
 macro_rules! stringify {
@@ -108,3 +164,62 @@ macro_rules! stringify {
         /* compiler built-in */
     };
 }
+
+#[macro_export]
+macro_rules! panic {
+    ($msg:literal) => {
+        $crate::panic(&$msg)
+    };
+}
+
+#[rustc_intrinsic]
+#[rustc_intrinsic_const_stable_indirect]
+#[rustc_intrinsic_must_be_overridden]
+pub const fn size_of<T>() -> usize {
+    loop {}
+}
+
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const fn abort() -> ! {
+    loop {}
+}
+
+#[lang = "panic"]
+#[rustc_const_panic_str]
+const fn panic(_expr: &&'static str) -> ! {
+    abort();
+}
+
+#[lang = "eq"]
+pub trait PartialEq<Rhs: ?Sized = Self> {
+    fn eq(&self, other: &Rhs) -> bool;
+    fn ne(&self, other: &Rhs) -> bool {
+        !self.eq(other)
+    }
+}
+
+impl PartialEq for usize {
+    fn eq(&self, other: &usize) -> bool {
+        (*self) == (*other)
+    }
+}
+
+impl PartialEq for bool {
+    fn eq(&self, other: &bool) -> bool {
+        (*self) == (*other)
+    }
+}
+
+#[lang = "not"]
+pub trait Not {
+    type Output;
+    fn not(self) -> Self::Output;
+}
+
+impl Not for bool {
+    type Output = bool;
+    fn not(self) -> Self {
+        !self
+    }
+}
diff --git a/tests/run-make/core-ffi-typecheck-clang/rmake.rs b/tests/run-make/core-ffi-typecheck-clang/rmake.rs
new file mode 100644
index 0000000000000..b0d500b1bb0fd
--- /dev/null
+++ b/tests/run-make/core-ffi-typecheck-clang/rmake.rs
@@ -0,0 +1,194 @@
+//@ needs-force-clang-based-tests
+// This test checks that the clang defines for each target allign with the core ffi types defined in
+// mod.rs. Therefore each rust target is queried and the clang defines for each target are read and
+// compared to the core sizes to verify all types and sizes allign at buildtime.
+//
+// If this test fails because Rust adds a target that Clang does not support, this target should be
+// added to SKIPPED_TARGETS.
+
+use run_make_support::{clang, regex, rfs, rustc, serde_json};
+use serde_json::Value;
+
+// It is not possible to run the Rust test-suite on these targets.
+const SKIPPED_TARGETS: &[&str] = &[
+    "xtensa-esp32-espidf",
+    "xtensa-esp32-none-elf",
+    "xtensa-esp32s2-espidf",
+    "xtensa-esp32s2-none-elf",
+    "xtensa-esp32s3-espidf",
+    "xtensa-esp32s3-none-elf",
+    "csky-unknown-linux-gnuabiv2",
+    "csky-unknown-linux-gnuabiv2hf",
+];
+
+const MAPPED_TARGETS: &[(&str, &str)] = &[
+    ("armv5te-unknown-linux-uclibcgnueabi", "armv5te-unknown-linux"),
+    ("mips-unknown-linux-uclibc", "mips-unknown-linux"),
+    ("mipsel-unknown-linux-uclibc", "mips-unknown-linux"),
+    ("powerpc-unknown-linux-gnuspe", "powerpc-unknown-linux-gnu"),
+    ("powerpc-unknown-linux-muslspe", "powerpc-unknown-linux-musl"),
+    ("x86_64-unknown-l4re-uclibc", "x86_64-unknown-l4re"),
+];
+
+fn main() {
+    let minicore_path = run_make_support::source_root().join("tests/auxiliary/minicore.rs");
+
+    preprocess_core_ffi();
+
+    let targets_json =
+        rustc().arg("--print").arg("all-target-specs-json").arg("-Z").arg("unstable-options").run();
+    let targets_json_str =
+        String::from_utf8(targets_json.stdout().to_vec()).expect("error not a string");
+
+    let j: Value = serde_json::from_str(&targets_json_str).unwrap();
+    for (target, v) in j.as_object().unwrap() {
+        let llvm_target = &v["llvm-target"].as_str().unwrap();
+
+        if SKIPPED_TARGETS.iter().any(|&to_skip_target| target == to_skip_target) {
+            continue;
+        }
+
+        // Create a new variable to hold either the mapped target or original llvm_target
+        let target_to_use = MAPPED_TARGETS
+            .iter()
+            .find(|&&(from, _)| from == *llvm_target)
+            .map(|&(_, to)| to)
+            .unwrap_or(llvm_target);
+
+        // Run Clang's preprocessor for the relevant target, printing default macro definitions.
+        let clang_output =
+            clang().args(&["-E", "-dM", "-x", "c", "/dev/null", "-target", &target_to_use]).run();
+
+        let defines = String::from_utf8(clang_output.stdout()).expect("Invalid UTF-8");
+
+        let minicore_content = rfs::read_to_string(&minicore_path);
+        let mut rmake_content = format!(
+            r#"
+            #![no_std]
+            #![no_core]
+            #![feature(link_cfg)]
+            #![allow(unused)]
+            #![crate_type = "rlib"]
+
+            /* begin minicore content */
+            {minicore_content}
+            /* end minicore content */
+
+            #[path = "processed_mod.rs"]
+            mod ffi;
+            #[path = "tests.rs"]
+            mod tests;
+            "#
+        );
+
+        rmake_content.push_str(&format!(
+            "
+            const CLANG_C_CHAR_SIZE: usize = {};
+            const CLANG_C_CHAR_SIGNED: bool = {};
+            const CLANG_C_SHORT_SIZE: usize = {};
+            const CLANG_C_INT_SIZE: usize = {};
+            const CLANG_C_LONG_SIZE: usize = {};
+            const CLANG_C_LONGLONG_SIZE: usize = {};
+            const CLANG_C_FLOAT_SIZE: usize = {};
+            const CLANG_C_DOUBLE_SIZE: usize = {};
+            const CLANG_C_SIZE_T_SIZE: usize = {};
+            const CLANG_C_PTRDIFF_T_SIZE: usize = {};
+            ",
+            parse_size(&defines, "CHAR"),
+            char_is_signed(&defines),
+            parse_size(&defines, "SHORT"),
+            parse_size(&defines, "INT"),
+            parse_size(&defines, "LONG"),
+            parse_size(&defines, "LONG_LONG"),
+            parse_size(&defines, "FLOAT"),
+            parse_size(&defines, "DOUBLE"),
+            parse_size(&defines, "SIZE_T"),
+            parse_size(&defines, "PTRDIFF_T"),
+        ));
+
+        // Generate a target-specific rmake file.
+        // If type misalignments occur,
+        // generated rmake file name used to identify the failing target.
+        let file_name = format!("{}_rmake.rs", target.replace("-", "_").replace(".", "_"));
+
+        // Attempt to build the test file for the relevant target.
+        // Tests use constant evaluation, so running is not necessary.
+        rfs::write(&file_name, rmake_content);
+        let rustc_output = rustc()
+            .arg("-Zunstable-options")
+            .arg("--emit=metadata")
+            .arg("--target")
+            .arg(target)
+            .arg("-o-")
+            .arg(&file_name)
+            .run();
+        rfs::remove_file(&file_name);
+        if !rustc_output.status().success() {
+            panic!("Failed for target {}", target);
+        }
+    }
+
+    // Cleanup
+    rfs::remove_file("processed_mod.rs");
+}
+
+// Helper to parse size from clang defines
+fn parse_size(defines: &str, type_name: &str) -> usize {
+    let search_pattern = format!("__SIZEOF_{}__ ", type_name.to_uppercase());
+    for line in defines.lines() {
+        if line.contains(&search_pattern) {
+            if let Some(size_str) = line.split_whitespace().last() {
+                return size_str.parse().unwrap_or(0);
+            }
+        }
+    }
+
+    // Only allow CHAR to default to 1
+    if type_name.to_uppercase() == "CHAR" {
+        return 1;
+    }
+
+    panic!("Could not find size definition for type: {}", type_name);
+}
+
+fn char_is_signed(defines: &str) -> bool {
+    !defines.lines().any(|line| line.contains("__CHAR_UNSIGNED__"))
+}
+
+/// Parse core/ffi/mod.rs to retrieve only necessary macros and type defines
+fn preprocess_core_ffi() {
+    let mod_path = run_make_support::source_root().join("library/core/src/ffi/mod.rs");
+    let mut content = rfs::read_to_string(&mod_path);
+
+    //remove stability features #![unstable]
+    let mut re = regex::Regex::new(r"#!?\[(un)?stable[^]]*?\]").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    //remove doc features #[doc...]
+    re = regex::Regex::new(r"#\[doc[^]]*?\]").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    //remove lang feature #[lang...]
+    re = regex::Regex::new(r"#\[lang[^]]*?\]").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    //remove non inline modules
+    re = regex::Regex::new(r".*mod.*;").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    //remove use
+    re = regex::Regex::new(r".*use.*;").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    //remove fn fmt {...}
+    re = regex::Regex::new(r"(?s)fn fmt.*?\{.*?\}").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    //rmv impl fmt {...}
+    re = regex::Regex::new(r"(?s)impl fmt::Debug for.*?\{.*?\}").unwrap();
+    content = re.replace_all(&content, "").to_string();
+
+    let file_name = "processed_mod.rs";
+
+    rfs::write(&file_name, content);
+}
diff --git a/tests/run-make/core-ffi-typecheck-clang/tests.rs b/tests/run-make/core-ffi-typecheck-clang/tests.rs
new file mode 100644
index 0000000000000..9dc44201ac766
--- /dev/null
+++ b/tests/run-make/core-ffi-typecheck-clang/tests.rs
@@ -0,0 +1,189 @@
+/// This file compares the size and signedness of Rust `c_*` types to those from Clang,
+/// based on the `CLANG_C_*` constants. Comparisons are done at compile time so this
+/// does not need to be executed.
+use super::*; // `super` will include everything from the common template
+
+trait Signed {
+    const SIGNED: bool;
+}
+
+// Verify Rust's 'c_long' is correct.
+cfg_if! {
+    if #[cfg(all(target_arch = "aarch64", target_abi = "ilp32"))] {
+        // FIXME: long is not long enough on aarch64 ilp32, should be 8, defaulting to 4
+        const XFAIL_C_LONG_SIZE: usize = 4;
+        pub const TEST_C_LONG_SIZE: () = if size_of::<ffi::c_long>() != XFAIL_C_LONG_SIZE {
+            panic!("mismatched c_long size, target_abi: ilp32");
+        };
+    }
+    else if #[cfg(all(target_arch = "aarch64", target_os = "uefi"))] {
+        // FIXME: c_long misallignment llvm target is aarch64-unknown-windows,
+        // discrepencies between Rust target configuration and LLVM alias.
+        const XFAIL_C_LONG_SIZE: usize = 8;
+        pub const TEST_C_LONG_SIZE: () = if size_of::<ffi::c_long>() != XFAIL_C_LONG_SIZE {
+            panic!("mismatched c_long size, target_os: uefi");
+        };
+    }
+    else if #[cfg(all(target_arch = "x86_64", target_os = "uefi"))] {
+        // FIXME: c_long misallignment llvm target is x86_64-unknown-windows,
+        // discrepencies between Rust target configuration and LLVM alias.
+        const XFAIL_C_LONG_SIZE: usize = 8;
+        pub const TEST_C_LONG_SIZE: () = if size_of::<ffi::c_long>() != XFAIL_C_LONG_SIZE {
+            panic!("mismatched c_long size, target_os: uefi");
+        };
+    }
+    else {
+        // Default test
+        pub const TEST_C_LONG_SIZE: () = if size_of::<ffi::c_long>() != CLANG_C_LONG_SIZE {
+            panic!("wrong c_long size");
+        };
+    }
+}
+
+// Verify Rust's 'c_char' has correct sign.
+cfg_if! {
+    if #[cfg(target_arch = "msp430")] {
+        // FIXME: c_char signedness misallignment on msp430, should be signed on CLANG
+        const XFAIL_C_CHAR_SIGNED: bool = false;
+        pub const TEST_C_CHAR_UNSIGNED: () = if ffi::c_char::SIGNED != XFAIL_C_CHAR_SIGNED {
+            panic!("mismatched c_char signed, target_arch: msp430");
+        };
+    }
+    else if #[cfg(all(target_arch = "aarch64", target_os = "uefi"))] {
+        // FIXME: c_char signedness misallignment llvm target is aarch64-unknown-windows,
+        // discrepencies between Rust target configuration and LLVM alias.
+        const XFAIL_C_CHAR_SIGNED: bool = false;
+        pub const TEST_C_CHAR_UNSIGNED: () = if ffi::c_char::SIGNED != XFAIL_C_CHAR_SIGNED {
+            panic!("mismatched c_char signed, target_os: uefi");
+        };
+    }
+    else {
+        pub const TEST_C_CHAR_UNSIGNED: () = if ffi::c_char::SIGNED != CLANG_C_CHAR_SIGNED {
+            panic!("mismatched c_char sign");
+        };
+    }
+}
+
+// Verify Rust's 'c_double' is correct.
+cfg_if! {
+    if #[cfg(target_arch = "avr")] {
+        // FIXME: double is not short enough on avr-unknown-gnu-atmega328 (should be 4 bytes)
+        const XFAIL_C_DOUBLE_SIZE: usize = 8;
+        pub const TEST_C_DOUBLE_SIZE: () = if size_of::<ffi::c_double>() != XFAIL_C_DOUBLE_SIZE {
+            panic!("wrong c_double size, target_arch: avr");
+        };
+    }
+    else {
+        pub const TEST_C_DOUBLE_SIZE: () = if size_of::<ffi::c_double>() != CLANG_C_DOUBLE_SIZE {
+            panic!("wrong c_double size");
+        };
+    }
+}
+
+// Verify Rust's 'c_size_t' is correct
+cfg_if! {
+    if #[cfg(all(target_arch = "aarch64", target_abi = "ilp32"))] {
+        // FIXME: size_t is not short enough on aarch64 ilp32, should be 4, defaulting to 8
+        const XFAIL_C_SIZE_T_SIZE: usize = 4;
+        pub const TEST_C_SIZE_T_SIZE: () = if size_of::<ffi::c_size_t>() != XFAIL_C_SIZE_T_SIZE {
+            panic!("wrong c_size_t size, target_arch: aarch64, target_abi: ilp32");
+        };
+    }
+    else {
+        pub const TEST_C_SIZE_T_SIZE: () = if size_of::<ffi::c_size_t>() != CLANG_C_SIZE_T_SIZE {
+            panic!("wrong c_size_t size");
+        };
+    }
+}
+
+// Verify Rust's 'c_ssize_t' is correct
+cfg_if! {
+    if #[cfg(all(target_arch = "aarch64", target_abi = "ilp32"))] {
+        // FIXME: ssize_t is not short enough on aarch64 ilp32, should be 4, defaulting to 8
+        const XFAIL_C_SSIZE_T_SIZE: usize = 4;
+        pub const TEST_C_SSIZE_T_SIZE: () = if size_of::<ffi::c_ssize_t>() != XFAIL_C_SSIZE_T_SIZE {
+            panic!("wrong c_ssize_t size, target_arch: aarch64, target_abi: ilp32");
+        };
+    }
+    else {
+        pub const TEST_C_SSIZE_T_SIZE: () = if size_of::<ffi::c_ssize_t>() != CLANG_C_SIZE_T_SIZE {
+            panic!("wrong c_size_t size");
+        };
+    }
+}
+
+// Verify Rust's 'c_ptrdiff_t' is correct
+cfg_if! {
+    if #[cfg(all(target_arch = "aarch64", target_abi = "ilp32"))] {
+        // FIXME: c_ptrdiff_t is not short enough on aarch64 ilp32, should be 4, defaulting to 8
+        const XFAIL_C_PTRDIFF_T_SIZE: usize = 4;
+        pub const TEST_C_PTRDIFF_T_SIZE: () =
+            if size_of::<ffi::c_ptrdiff_t>() != XFAIL_C_PTRDIFF_T_SIZE {
+            panic!("wrong c_ssize_t size, target_arch: aarch64, target_abi: ilp32");
+        };
+    }
+    else {
+        pub const TEST_C_PTRDIFF_T_SIZE: () =
+            if size_of::<ffi::c_ptrdiff_t>() != CLANG_C_PTRDIFF_T_SIZE {
+            panic!("wrong c_size_t size");
+        };
+    }
+}
+
+impl Signed for i8 {
+    const SIGNED: bool = true;
+}
+
+impl Signed for u8 {
+    const SIGNED: bool = false;
+}
+
+//c_char size
+pub const TEST_C_CHAR_SIZE: () = if size_of::<ffi::c_char>() != CLANG_C_CHAR_SIZE {
+    panic!("wrong c_char size");
+};
+
+//c_int size
+pub const TEST_C_INT_SIZE: () = if size_of::<ffi::c_int>() != CLANG_C_INT_SIZE {
+    panic!("mismatched c_int size");
+};
+
+//c_short size
+pub const TEST_C_SHORT_SIZE: () = if size_of::<ffi::c_short>() != CLANG_C_SHORT_SIZE {
+    panic!("wrong c_short size");
+};
+
+//c_longlong size
+pub const TEST_C_LONGLONG_SIZE: () = if size_of::<ffi::c_longlong>() != CLANG_C_LONGLONG_SIZE {
+    panic!("wrong c_longlong size");
+};
+
+//c_float size
+pub const TEST_C_FLOAT_SIZE: () = if size_of::<ffi::c_float>() != CLANG_C_FLOAT_SIZE {
+    panic!("wrong c_float size");
+};
+
+//c_schar size
+pub const TEST_C_SCHAR_SIZE: () = if size_of::<ffi::c_schar>() != CLANG_C_CHAR_SIZE {
+    panic!("wrong c_schar size");
+};
+
+//c_uchar size
+pub const TEST_C_UCHAR_SIZE: () = if size_of::<ffi::c_uchar>() != CLANG_C_CHAR_SIZE {
+    panic!("wrong c_uchar size");
+};
+
+//c_uint size
+pub const TEST_C_UINT_SIZE: () = if size_of::<ffi::c_int>() != CLANG_C_INT_SIZE {
+    panic!("mismatched c_uint size");
+};
+
+//c_ushort size
+pub const TEST_C_USHORT_SIZE: () = if size_of::<ffi::c_short>() != CLANG_C_SHORT_SIZE {
+    panic!("wrong c_ushort size");
+};
+
+//c_ulonglong size
+pub const TEST_C_ULONGLONG_SIZE: () = if size_of::<ffi::c_ulonglong>() != CLANG_C_LONGLONG_SIZE {
+    panic!("wrong c_ulonglong size");
+};