Commit ac546f56eb

@@ -2903,7 +2903,17 @@ fn detectLibCIncludeDirs(
     if (target_util.canBuildLibC(target)) {
         const generic_name = target_util.libCGenericName(target);
         // Some architectures are handled by the same set of headers.
-        const arch_name = if (target.abi.isMusl()) target_util.archMuslName(target.cpu.arch) else @tagName(target.cpu.arch);
+        const arch_name = if (target.abi.isMusl())
+            target_util.archMuslName(target.cpu.arch)
+        else if (target.cpu.arch.isThumb())
+            // ARM headers are valid for Thumb too.
+            switch (target.cpu.arch) {
+                .thumb => "arm",
+                .thumbeb => "armeb",
+                else => unreachable,
+            }
+        else
+            @tagName(target.cpu.arch);
         const os_name = @tagName(target.os.tag);
         // Musl's headers are ABI-agnostic and so they all have the "musl" ABI name.
         const abi_name = if (target.abi.isMusl()) "musl" else @tagName(target.abi);

@@ -24,6 +24,10 @@ pub const available_libcs = [_]ArchOsAbi{
     .{ .arch = .arm, .os = .linux, .abi = .gnueabihf },
     .{ .arch = .arm, .os = .linux, .abi = .musleabi },
     .{ .arch = .arm, .os = .linux, .abi = .musleabihf },
+    .{ .arch = .thumb, .os = .linux, .abi = .gnueabi },
+    .{ .arch = .thumb, .os = .linux, .abi = .gnueabihf },
+    .{ .arch = .thumb, .os = .linux, .abi = .musleabi },
+    .{ .arch = .thumb, .os = .linux, .abi = .musleabihf },
     .{ .arch = .arm, .os = .windows, .abi = .gnu },
     .{ .arch = .csky, .os = .linux, .abi = .gnueabi },
     .{ .arch = .csky, .os = .linux, .abi = .gnueabihf },
@@ -97,7 +101,7 @@ pub fn libCGenericName(target: std.Target) [:0]const u8 {
 pub fn archMuslName(arch: std.Target.Cpu.Arch) [:0]const u8 {
     switch (arch) {
         .aarch64, .aarch64_be => return "aarch64",
-        .arm, .armeb => return "arm",
+        .arm, .armeb, .thumb, .thumbeb => return "arm",
         .mips, .mipsel => return "mips",
         .mips64el, .mips64 => return "mips64",
         .powerpc => return "powerpc",