Prefer angled brackets over quotes for include directives.
See: https://en.cppreference.com/w/cpp/preprocessor/include.html.

--- a/iwyu_path_util.cc
+++ b/iwyu_path_util.cc
@@ -211,7 +211,7 @@ bool IsQuotedInclude(const string& s) {
 }

 string AddQuotes(string include_name, bool angled) {
-  if (angled) {
+  if (true) {
       return "<" + include_name + ">";
   }
   return "\"" + include_name + "\"";


Prefer C++ headers over C counterparts.
See: https://github.com/include-what-you-use/include-what-you-use/blob/clang_21/iwyu_include_picker.cc#L587-L629.

--- a/iwyu_include_picker.cc
+++ b/iwyu_include_picker.cc
@@ -100,20 +100,20 @@ const IncludeMapEntry libc_symbol_map[] = {
   // equal.  The visibility on the symbol-name is ignored; by convention
   // we always set it to kPrivate.
   { "_POSIX_VDISABLE", kPrivate, "<unistd.h>", kPublic },
-  { "abort", kPrivate, "<stdlib.h>", kPublic },
+  { "abort", kPrivate, "<stdlib.h>", kPrivate },
   { "aiocb", kPrivate, "<aio.h>", kPublic },
   { "blkcnt_t", kPrivate, "<sys/types.h>", kPublic },
   { "blksize_t", kPrivate, "<sys/types.h>", kPublic },
   { "cc_t", kPrivate, "<termios.h>", kPublic },
-  { "clock_t", kPrivate, "<time.h>", kPublic },
+  { "clock_t", kPrivate, "<time.h>", kPrivate },
   { "clock_t", kPrivate, "<sys/types.h>", kPublic },
   { "clockid_t", kPrivate, "<sys/types.h>", kPublic },
-  { "ctermid", kPrivate, "<stdio.h>", kPublic },
+  { "ctermid", kPrivate, "<stdio.h>", kPrivate },
   { "daddr_t", kPrivate, "<sys/types.h>", kPublic },
   { "dev_t", kPrivate, "<sys/types.h>", kPublic },
-  { "div_t", kPrivate, "<stdlib.h>", kPublic },
-  { "double_t", kPrivate, "<math.h>", kPublic },
-  { "error_t", kPrivate, "<errno.h>", kPublic },
+  { "div_t", kPrivate, "<stdlib.h>", kPrivate },
+  { "double_t", kPrivate, "<math.h>", kPrivate },
+  { "error_t", kPrivate, "<errno.h>", kPrivate },
   { "error_t", kPrivate, "<argp.h>", kPublic },
   { "error_t", kPrivate, "<argz.h>", kPublic },
   { "FD_CLR", kPrivate, "<sys/select.h>", kPublic },
@@ -122,10 +122,10 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "fd_set", kPrivate, "<sys/select.h>", kPublic },
   { "FD_SETSIZE", kPrivate, "<sys/select.h>", kPublic },
   { "FD_ZERO", kPrivate, "<sys/select.h>", kPublic },
-  { "fenv_t", kPrivate, "<fenv.h>", kPublic },
-  { "fexcept_t", kPrivate, "<fenv.h>", kPublic },
-  { "FILE", kPrivate, "<stdio.h>", kPublic },
-  { "float_t", kPrivate, "<math.h>", kPublic },
+  { "fenv_t", kPrivate, "<fenv.h>", kPrivate },
+  { "fexcept_t", kPrivate, "<fenv.h>", kPrivate },
+  { "FILE", kPrivate, "<stdio.h>", kPrivate },
+  { "float_t", kPrivate, "<math.h>", kPrivate },
   { "fsblkcnt_t", kPrivate, "<sys/types.h>", kPublic },
   { "fsfilcnt_t", kPrivate, "<sys/types.h>", kPublic },
   { "getopt", kPrivate, "<unistd.h>", kPublic },
@@ -135,31 +135,31 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "in_addr_t", kPrivate, "<netinet/in.h>", kPublic },
   { "in_port_t", kPrivate, "<netinet/in.h>", kPublic },
   { "id_t", kPrivate, "<sys/types.h>", kPublic },
-  { "imaxdiv_t", kPrivate, "<inttypes.h>", kPublic },
-  { "intmax_t", kPrivate, "<stdint.h>", kPublic },
-  { "uintmax_t", kPrivate, "<stdint.h>", kPublic },
+  { "imaxdiv_t", kPrivate, "<inttypes.h>", kPrivate },
+  { "intmax_t", kPrivate, "<stdint.h>", kPrivate },
+  { "uintmax_t", kPrivate, "<stdint.h>", kPrivate },
   { "ino64_t", kPrivate, "<sys/types.h>", kPublic },
   { "ino_t", kPrivate, "<sys/types.h>", kPublic },
-  { "int8_t", kPrivate, "<stdint.h>", kPublic },
-  { "int16_t", kPrivate, "<stdint.h>", kPublic },
-  { "int32_t", kPrivate, "<stdint.h>", kPublic },
-  { "int64_t", kPrivate, "<stdint.h>", kPublic },
-  { "uint8_t", kPrivate, "<stdint.h>", kPublic },
-  { "uint16_t", kPrivate, "<stdint.h>", kPublic },
-  { "uint32_t", kPrivate, "<stdint.h>", kPublic },
-  { "uint64_t", kPrivate, "<stdint.h>", kPublic },
-  { "intptr_t", kPrivate, "<stdint.h>", kPublic },
-  { "uintptr_t", kPrivate, "<stdint.h>", kPublic },
+  { "int8_t", kPrivate, "<stdint.h>", kPrivate },
+  { "int16_t", kPrivate, "<stdint.h>", kPrivate },
+  { "int32_t", kPrivate, "<stdint.h>", kPrivate },
+  { "int64_t", kPrivate, "<stdint.h>", kPrivate },
+  { "uint8_t", kPrivate, "<stdint.h>", kPrivate },
+  { "uint16_t", kPrivate, "<stdint.h>", kPrivate },
+  { "uint32_t", kPrivate, "<stdint.h>", kPrivate },
+  { "uint64_t", kPrivate, "<stdint.h>", kPrivate },
+  { "intptr_t", kPrivate, "<stdint.h>", kPrivate },
+  { "uintptr_t", kPrivate, "<stdint.h>", kPrivate },
   { "iovec", kPrivate, "<sys/uio.h>", kPublic },
-  { "itimerspec", kPrivate, "<time.h>", kPublic },
+  { "itimerspec", kPrivate, "<time.h>", kPrivate },
   { "key_t", kPrivate, "<sys/types.h>", kPublic },
-  { "L_ctermid", kPrivate, "<stdio.h>", kPublic },
-  { "lconv", kPrivate, "<locale.h>", kPublic },
-  { "ldiv_t", kPrivate, "<stdlib.h>", kPublic },
-  { "lldiv_t", kPrivate, "<stdlib.h>", kPublic },
-  { "locale_t", kPrivate, "<locale.h>", kPublic },
-  { "max_align_t", kPrivate, "<stddef.h>", kPublic },
-  { "mbstate_t", kPrivate, "<wchar.h>", kPublic },
+  { "L_ctermid", kPrivate, "<stdio.h>", kPrivate },
+  { "lconv", kPrivate, "<locale.h>", kPrivate },
+  { "ldiv_t", kPrivate, "<stdlib.h>", kPrivate },
+  { "lldiv_t", kPrivate, "<stdlib.h>", kPrivate },
+  { "locale_t", kPrivate, "<locale.h>", kPrivate },
+  { "max_align_t", kPrivate, "<stddef.h>", kPrivate },
+  { "mbstate_t", kPrivate, "<wchar.h>", kPrivate },
   { "mcontext_t", kPrivate, "<ucontext.h>", kPublic },
   { "mode_t", kPrivate, "<sys/types.h>", kPublic },
   { "nl_item", kPrivate, "<nl_types.h>", kPublic },
@@ -175,8 +175,8 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "optind", kPrivate, "<unistd.h>", kPublic },
   { "optopt", kPrivate, "<unistd.h>", kPublic },
   { "pid_t", kPrivate, "<sys/types.h>", kPublic },
-  { "posix_memalign", kPrivate, "<stdlib.h>", kPublic },
-  { "printf", kPrivate, "<stdio.h>", kPublic },
+  { "posix_memalign", kPrivate, "<stdlib.h>", kPrivate },
+  { "printf", kPrivate, "<stdio.h>", kPrivate },
   { "pthread_attr_t", kPrivate, "<pthread.h>", kPublic },
   { "pthread_cond_t", kPrivate, "<pthread.h>", kPublic },
   { "pthread_condattr_t", kPrivate, "<pthread.h>", kPublic },
@@ -187,7 +187,7 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "pthread_rwlock_t", kPrivate, "<pthread.h>", kPublic },
   { "pthread_rwlockattr_t", kPrivate, "<pthread.h>", kPublic },
   { "pthread_t", kPrivate, "<pthread.h>", kPublic },
-  { "ptrdiff_t", kPrivate, "<stddef.h>", kPublic },
+  { "ptrdiff_t", kPrivate, "<stddef.h>", kPrivate },
   { "regex_t", kPrivate, "<regex.h>", kPublic },
   { "regmatch_t", kPrivate, "<regex.h>", kPublic },
   { "regoff_t", kPrivate, "<regex.h>", kPublic },
@@ -218,51 +218,51 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "SCHED_FIFO", kPrivate, "<sched.h>", kPublic },
   { "SCHED_OTHER", kPrivate, "<sched.h>", kPublic },
   { "SCHED_RR", kPrivate, "<sched.h>", kPublic },
-  { "SEEK_CUR", kPrivate, "<stdio.h>", kPublic },
-  { "SEEK_END", kPrivate, "<stdio.h>", kPublic },
-  { "SEEK_SET", kPrivate, "<stdio.h>", kPublic },
-  { "sig_atomic_t", kPrivate, "<signal.h>", kPublic },
-  { "sigevent", kPrivate, "<signal.h>", kPublic },
-  { "siginfo_t", kPrivate, "<signal.h>", kPublic },
-  { "sigset_t", kPrivate, "<signal.h>", kPublic },
-  { "sigval", kPrivate, "<signal.h>", kPublic },
+  { "SEEK_CUR", kPrivate, "<stdio.h>", kPrivate },
+  { "SEEK_END", kPrivate, "<stdio.h>", kPrivate },
+  { "SEEK_SET", kPrivate, "<stdio.h>", kPrivate },
+  { "sig_atomic_t", kPrivate, "<signal.h>", kPrivate },
+  { "sigevent", kPrivate, "<signal.h>", kPrivate },
+  { "siginfo_t", kPrivate, "<signal.h>", kPrivate },
+  { "sigset_t", kPrivate, "<signal.h>", kPrivate },
+  { "sigval", kPrivate, "<signal.h>", kPrivate },
   { "sockaddr", kPrivate, "<sys/socket.h>", kPublic },
   { "socklen_t", kPrivate, "<sys/socket.h>", kPublic },
   { "ssize_t", kPrivate, "<sys/types.h>", kPublic },
-  { "stack_t", kPrivate, "<signal.h>", kPublic },
+  { "stack_t", kPrivate, "<signal.h>", kPrivate },
   { "stat", kPrivate, "<sys/stat.h>", kPublic },
   { "suseconds_t", kPrivate, "<sys/types.h>", kPublic },
-  { "time_t", kPrivate, "<time.h>", kPublic },
+  { "time_t", kPrivate, "<time.h>", kPrivate },
   { "time_t", kPrivate, "<sys/types.h>", kPublic },
   { "timer_t", kPrivate, "<sys/types.h>", kPublic },
-  { "timespec", kPrivate, "<time.h>", kPublic },
+  { "timespec", kPrivate, "<time.h>", kPrivate },
   { "timeval", kPrivate, "<sys/time.h>", kPublic },
-  { "tm", kPrivate, "<time.h>", kPublic },
+  { "tm", kPrivate, "<time.h>", kPrivate },
   { "u_char", kPrivate, "<sys/types.h>", kPublic },
   { "ucontext_t", kPrivate, "<ucontext.h>", kPublic },
   { "uid_t", kPrivate, "<sys/types.h>", kPublic },
   { "useconds_t", kPrivate, "<sys/types.h>", kPublic },
-  { "wchar_t", kPrivate, "<stddef.h>", kPublic },
-  { "wctrans_t", kPrivate, "<wctype.h>", kPublic },
-  { "wctype_t", kPrivate, "<wctype.h>", kPublic },
+  { "wchar_t", kPrivate, "<stddef.h>", kPrivate },
+  { "wctrans_t", kPrivate, "<wctype.h>", kPrivate },
+  { "wctype_t", kPrivate, "<wctype.h>", kPrivate },
   { "winsize", kPrivate, "<termios.h>", kPublic },
-  { "wint_t", kPrivate, "<wchar.h>", kPublic },
+  { "wint_t", kPrivate, "<wchar.h>", kPrivate },
   // It is unspecified if the cname headers provide ::size_t.
   // <locale.h> is the one header which defines NULL but not size_t.
-  { "size_t", kPrivate, "<stddef.h>", kPublic },  // 'canonical' location for size_t
-  { "size_t", kPrivate, "<signal.h>", kPublic },
-  { "size_t", kPrivate, "<stdio.h>", kPublic },
-  { "size_t", kPrivate, "<stdlib.h>", kPublic },
-  { "size_t", kPrivate, "<string.h>", kPublic },
-  { "size_t", kPrivate, "<time.h>", kPublic },
-  { "size_t", kPrivate, "<uchar.h>", kPublic },
-  { "size_t", kPrivate, "<wchar.h>", kPublic },
+  { "size_t", kPrivate, "<stddef.h>", kPrivate },  // 'canonical' location for size_t
+  { "size_t", kPrivate, "<signal.h>", kPrivate },
+  { "size_t", kPrivate, "<stdio.h>", kPrivate },
+  { "size_t", kPrivate, "<stdlib.h>", kPrivate },
+  { "size_t", kPrivate, "<string.h>", kPrivate },
+  { "size_t", kPrivate, "<time.h>", kPrivate },
+  { "size_t", kPrivate, "<uchar.h>", kPrivate },
+  { "size_t", kPrivate, "<wchar.h>", kPrivate },
   // Macros that can be defined in more than one file, don't have the
   // same __foo_defined guard that other types do, so the grep above
   // doesn't discover them.  Until I figure out a better way, I just
   // add them in by hand as I discover them.
-  { "EOF", kPrivate, "<stdio.h>", kPublic },
-  { "FILE", kPrivate, "<stdio.h>", kPublic },
+  { "EOF", kPrivate, "<stdio.h>", kPrivate },
+  { "FILE", kPrivate, "<stdio.h>", kPrivate },
   { "IBSHIFT", kPrivate, "<asm/termbits.h>", kPublic },
   { "MAP_POPULATE", kPrivate, "<sys/mman.h>", kPublic },
   { "MAP_POPULATE", kPrivate, "<linux/mman.h>", kPublic },
@@ -270,22 +270,22 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "MAP_STACK", kPrivate, "<linux/mman.h>", kPublic },
   { "MAXHOSTNAMELEN", kPrivate, "<sys/param.h>", kPublic },
   { "MAXHOSTNAMELEN", kPrivate, "<protocols/timed.h>", kPublic },
-  { "SIGABRT", kPrivate, "<signal.h>", kPublic },
-  { "SIGCHLD", kPrivate, "<signal.h>", kPublic },
-  { "va_arg", kPrivate, "<stdarg.h>", kPublic },
-  { "va_copy", kPrivate, "<stdarg.h>", kPublic },
-  { "va_end", kPrivate, "<stdarg.h>", kPublic },
-  { "va_list", kPrivate, "<stdarg.h>", kPublic },
-  { "va_start", kPrivate, "<stdarg.h>", kPublic },
-  { "WEOF", kPrivate, "<wchar.h>", kPublic },
+  { "SIGABRT", kPrivate, "<signal.h>", kPrivate },
+  { "SIGCHLD", kPrivate, "<signal.h>", kPrivate },
+  { "va_arg", kPrivate, "<stdarg.h>", kPrivate },
+  { "va_copy", kPrivate, "<stdarg.h>", kPrivate },
+  { "va_end", kPrivate, "<stdarg.h>", kPrivate },
+  { "va_list", kPrivate, "<stdarg.h>", kPrivate },
+  { "va_start", kPrivate, "<stdarg.h>", kPrivate },
+  { "WEOF", kPrivate, "<wchar.h>", kPrivate },
   // These are symbols that could be defined in either stdlib.h or
   // malloc.h, but we always want the stdlib location.
-  { "malloc", kPrivate, "<stdlib.h>", kPublic },
-  { "calloc", kPrivate, "<stdlib.h>", kPublic },
-  { "realloc", kPrivate, "<stdlib.h>", kPublic },
-  { "free", kPrivate, "<stdlib.h>", kPublic },
+  { "malloc", kPrivate, "<stdlib.h>", kPrivate },
+  { "calloc", kPrivate, "<stdlib.h>", kPrivate },
+  { "realloc", kPrivate, "<stdlib.h>", kPrivate },
+  { "free", kPrivate, "<stdlib.h>", kPrivate },
   // Entries for NULL
-  { "NULL", kPrivate, "<stddef.h>", kPublic },  // 'canonical' location for NULL
+  { "NULL", kPrivate, "<stddef.h>", kPrivate },  // 'canonical' location for NULL
   { "NULL", kPrivate, "<clocale>", kPublic },
   { "NULL", kPrivate, "<cstddef>", kPublic },
   { "NULL", kPrivate, "<cstdio>", kPublic },
@@ -293,13 +293,13 @@ const IncludeMapEntry libc_symbol_map[] = {
   { "NULL", kPrivate, "<cstring>", kPublic },
   { "NULL", kPrivate, "<ctime>", kPublic },
   { "NULL", kPrivate, "<cwchar>", kPublic },
-  { "NULL", kPrivate, "<locale.h>", kPublic },
-  { "NULL", kPrivate, "<stdio.h>", kPublic },
-  { "NULL", kPrivate, "<stdlib.h>", kPublic },
-  { "NULL", kPrivate, "<string.h>", kPublic },
-  { "NULL", kPrivate, "<time.h>", kPublic },
-  { "NULL", kPrivate, "<wchar.h>", kPublic },
-  { "offsetof", kPrivate, "<stddef.h>", kPublic },
+  { "NULL", kPrivate, "<locale.h>", kPrivate },
+  { "NULL", kPrivate, "<stdio.h>", kPrivate },
+  { "NULL", kPrivate, "<stdlib.h>", kPrivate },
+  { "NULL", kPrivate, "<string.h>", kPrivate },
+  { "NULL", kPrivate, "<time.h>", kPrivate },
+  { "NULL", kPrivate, "<wchar.h>", kPrivate },
+  { "offsetof", kPrivate, "<stddef.h>", kPrivate },
 };
 
 // Common kludges for C++ standard libraries
@@ -355,7 +355,7 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/a.out.h>", kPrivate, "<a.out.h>", kPublic },
   { "<bits/auxv.h>", kPrivate, "<sys/auxv.h>", kPublic },
   { "<bits/byteswap.h>", kPrivate, "<byteswap.h>", kPublic },
-  { "<bits/cmathcalls.h>", kPrivate, "<complex.h>", kPublic },
+  { "<bits/cmathcalls.h>", kPrivate, "<complex.h>", kPrivate },
   { "<bits/confname.h>", kPrivate, "<unistd.h>", kPublic },
   { "<bits/dirent.h>", kPrivate, "<dirent.h>", kPublic },
   { "<bits/dlfcn.h>", kPrivate, "<dlfcn.h>", kPublic },
@@ -363,18 +363,18 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/endian.h>", kPrivate, "<endian.h>", kPublic },
   { "<bits/environments.h>", kPrivate, "<unistd.h>", kPublic },
   { "<bits/epoll.h>", kPrivate, "<sys/epoll.h>", kPublic },
-  { "<bits/errno.h>", kPrivate, "<errno.h>", kPublic },
+  { "<bits/errno.h>", kPrivate, "<errno.h>", kPrivate },
   { "<bits/error.h>", kPrivate, "<error.h>", kPublic },
   { "<bits/eventfd.h>", kPrivate, "<sys/eventfd.h>", kPublic },
   { "<bits/fcntl.h>", kPrivate, "<fcntl.h>", kPublic },
   { "<bits/fcntl2.h>", kPrivate, "<fcntl.h>", kPublic },
-  { "<bits/fenv.h>", kPrivate, "<fenv.h>", kPublic },
-  { "<bits/fenvinline.h>", kPrivate, "<fenv.h>", kPublic },
-  { "<bits/huge_val.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/huge_valf.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/huge_vall.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/fenv.h>", kPrivate, "<fenv.h>", kPrivate },
+  { "<bits/fenvinline.h>", kPrivate, "<fenv.h>", kPrivate },
+  { "<bits/huge_val.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/huge_valf.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/huge_vall.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/hwcap.h>", kPrivate, "<sys/auxv.h>", kPublic },
-  { "<bits/inf.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/inf.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/inotify.h>", kPrivate, "<sys/inotify.h>", kPublic },
   { "<bits/ioctl-types.h>", kPrivate, "<sys/ioctl.h>", kPublic },
   { "<bits/ioctls.h>", kPrivate, "<sys/ioctl.h>", kPublic },
@@ -382,24 +382,24 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/ipctypes.h>", kPrivate, "<sys/ipc.h>", kPublic },
   { "<bits/libio-ldbl.h>", kPrivate, "<libio.h>", kPublic },
   { "<bits/link.h>", kPrivate, "<link.h>", kPublic },
-  { "<bits/locale.h>", kPrivate, "<locale.h>", kPublic },
-  { "<bits/math-finite.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/mathcalls.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/mathdef.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/mathinline.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/locale.h>", kPrivate, "<locale.h>", kPrivate },
+  { "<bits/math-finite.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/mathcalls.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/mathdef.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/mathinline.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/mman.h>", kPrivate, "<sys/mman.h>", kPublic },
   { "<bits/mman-shared.h>", kPrivate, "<sys/mman.h>", kPublic },
   { "<bits/monetary-ldbl.h>", kPrivate, "<monetary.h>", kPublic },
   { "<bits/mqueue.h>", kPrivate, "<mqueue.h>", kPublic },
   { "<bits/mqueue2.h>", kPrivate, "<mqueue.h>", kPublic },
   { "<bits/msq.h>", kPrivate, "<sys/msg.h>", kPublic },
-  { "<bits/nan.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/nan.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/netdb.h>", kPrivate, "<netdb.h>", kPublic },
   { "<bits/param.h>", kPrivate, "<sys/param.h>", kPublic },
   { "<bits/poll.h>", kPrivate, "<sys/poll.h>", kPrivate },
   { "<bits/poll2.h>", kPrivate, "<sys/poll.h>", kPrivate },
-  { "<bits/posix1_lim.h>", kPrivate, "<limits.h>", kPublic },
-  { "<bits/posix2_lim.h>", kPrivate, "<limits.h>", kPublic },
+  { "<bits/posix1_lim.h>", kPrivate, "<limits.h>", kPrivate },
+  { "<bits/posix2_lim.h>", kPrivate, "<limits.h>", kPrivate },
   { "<bits/posix_opt.h>", kPrivate, "<unistd.h>", kPublic },
   { "<bits/printf-ldbl.h>", kPrivate, "<printf.h>", kPublic },
   { "<bits/pthreadtypes.h>", kPrivate, "<pthread.h>", kPublic },
@@ -409,17 +409,17 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/select2.h>", kPrivate, "<sys/select.h>", kPublic },
   { "<bits/sem.h>", kPrivate, "<sys/sem.h>", kPublic },
   { "<bits/semaphore.h>", kPrivate, "<semaphore.h>", kPublic },
-  { "<bits/setjmp.h>", kPrivate, "<setjmp.h>", kPublic },
-  { "<bits/setjmp2.h>", kPrivate, "<setjmp.h>", kPublic },
+  { "<bits/setjmp.h>", kPrivate, "<setjmp.h>", kPrivate },
+  { "<bits/setjmp2.h>", kPrivate, "<setjmp.h>", kPrivate },
   { "<bits/shm.h>", kPrivate, "<sys/shm.h>", kPublic },
-  { "<bits/sigaction.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/sigcontext.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/siginfo.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/signum.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/signum-arch.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/sigset.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/sigstack.h>", kPrivate, "<signal.h>", kPublic },
-  { "<bits/sigthread.h>", kPrivate, "<signal.h>", kPublic },
+  { "<bits/sigaction.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/sigcontext.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/siginfo.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/signum.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/signum-arch.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/sigset.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/sigstack.h>", kPrivate, "<signal.h>", kPrivate },
+  { "<bits/sigthread.h>", kPrivate, "<signal.h>", kPrivate },
   { "<bits/sockaddr.h>", kPrivate, "<sys/un.h>", kPublic },
   { "<bits/socket.h>", kPrivate, "<sys/socket.h>", kPublic },
   { "<bits/socket2.h>", kPrivate, "<sys/socket.h>", kPublic },
@@ -429,22 +429,22 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/statfs.h>", kPrivate, "<sys/statfs.h>", kPublic },
   { "<bits/statvfs.h>", kPrivate, "<sys/statvfs.h>", kPublic },
   { "<bits/statx-generic.h>", kPrivate, "<sys/stat.h>", kPublic },
-  { "<bits/stdio-ldbl.h>", kPrivate, "<stdio.h>", kPublic },
+  { "<bits/stdio-ldbl.h>", kPrivate, "<stdio.h>", kPrivate },
   { "<bits/stdio-lock.h>", kPrivate, "<libio.h>", kPublic },
-  { "<bits/stdio.h>", kPrivate, "<stdio.h>", kPublic },
-  { "<bits/stdio2.h>", kPrivate, "<stdio.h>", kPublic },
-  { "<bits/stdio_lim.h>", kPrivate, "<stdio.h>", kPublic },
-  { "<bits/stdlib-bsearch.h>", kPrivate, "<stdlib.h>", kPublic },
-  { "<bits/stdlib-float.h>", kPrivate, "<stdlib.h>", kPublic },
-  { "<bits/stdlib-ldbl.h>", kPrivate, "<stdlib.h>", kPublic },
-  { "<bits/stdlib.h>", kPrivate, "<stdlib.h>", kPublic },
-  { "<bits/string.h>", kPrivate, "<string.h>", kPublic },
-  { "<bits/string2.h>", kPrivate, "<string.h>", kPublic },
-  { "<bits/string3.h>", kPrivate, "<string.h>", kPublic },
+  { "<bits/stdio.h>", kPrivate, "<stdio.h>", kPrivate },
+  { "<bits/stdio2.h>", kPrivate, "<stdio.h>", kPrivate },
+  { "<bits/stdio_lim.h>", kPrivate, "<stdio.h>", kPrivate },
+  { "<bits/stdlib-bsearch.h>", kPrivate, "<stdlib.h>", kPrivate },
+  { "<bits/stdlib-float.h>", kPrivate, "<stdlib.h>", kPrivate },
+  { "<bits/stdlib-ldbl.h>", kPrivate, "<stdlib.h>", kPrivate },
+  { "<bits/stdlib.h>", kPrivate, "<stdlib.h>", kPrivate },
+  { "<bits/string.h>", kPrivate, "<string.h>", kPrivate },
+  { "<bits/string2.h>", kPrivate, "<string.h>", kPrivate },
+  { "<bits/string3.h>", kPrivate, "<string.h>", kPrivate },
   { "<bits/stropts.h>", kPrivate, "<stropts.h>", kPublic },
   { "<bits/struct_stat.h>", kPrivate, "<sys/stat.h>", kPublic },
   { "<bits/struct_stat.h>", kPrivate, "<ftw.h>", kPublic },
-  { "<bits/sys_errlist.h>", kPrivate, "<stdio.h>", kPublic },
+  { "<bits/sys_errlist.h>", kPrivate, "<stdio.h>", kPrivate },
   { "<bits/syscall.h>", kPrivate, "<sys/syscall.h>", kPublic },
   { "<bits/sysctl.h>", kPrivate, "<sys/sysctl.h>", kPublic },
   { "<bits/syslog-ldbl.h>", kPrivate, "<sys/syslog.h>", kPrivate },
@@ -459,12 +459,12 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/termios-struct.h>", kPrivate, "<termios.h>", kPublic },
   { "<bits/termios-tcflow.h>", kPrivate, "<termios.h>", kPublic },
   { "<bits/termios.h>", kPrivate, "<termios.h>", kPublic },
-  { "<bits/time.h>", kPrivate, "<time.h>", kPublic },
+  { "<bits/time.h>", kPrivate, "<time.h>", kPrivate },
   { "<bits/time.h>", kPrivate, "<sys/time.h>", kPublic },
   { "<bits/timerfd.h>", kPrivate, "<sys/timerfd.h>", kPublic },
   { "<bits/timex.h>", kPrivate, "<sys/timex.h>", kPublic },
   { "<bits/types.h>", kPrivate, "<sys/types.h>", kPublic },
-  { "<bits/types/siginfo_t.h>", kPrivate, "<signal.h>", kPublic },
+  { "<bits/types/siginfo_t.h>", kPrivate, "<signal.h>", kPrivate },
   { "<bits/types/siginfo_t.h>", kPrivate, "<sys/wait.h>", kPublic },
   { "<bits/uio.h>", kPrivate, "<sys/uio.h>", kPublic },
   { "<bits/unistd.h>", kPrivate, "<unistd.h>", kPublic },
@@ -474,11 +474,11 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/utsname.h>", kPrivate, "<sys/utsname.h>", kPublic },
   { "<bits/waitflags.h>", kPrivate, "<sys/wait.h>", kPublic },
   { "<bits/waitstatus.h>", kPrivate, "<sys/wait.h>", kPublic },
-  { "<bits/wchar-ldbl.h>", kPrivate, "<wchar.h>", kPublic },
-  { "<bits/wchar.h>", kPrivate, "<wchar.h>", kPublic },
-  { "<bits/wchar2.h>", kPrivate, "<wchar.h>", kPublic },
-  { "<bits/wordsize.h>", kPrivate, "<limits.h>", kPublic },
-  { "<bits/xopen_lim.h>", kPrivate, "<limits.h>", kPublic },
+  { "<bits/wchar-ldbl.h>", kPrivate, "<wchar.h>", kPrivate },
+  { "<bits/wchar.h>", kPrivate, "<wchar.h>", kPrivate },
+  { "<bits/wchar2.h>", kPrivate, "<wchar.h>", kPrivate },
+  { "<bits/wordsize.h>", kPrivate, "<limits.h>", kPrivate },
+  { "<bits/xopen_lim.h>", kPrivate, "<limits.h>", kPrivate },
   { "<bits/xtitypes.h>", kPrivate, "<stropts.h>", kPublic },
   // Sometimes libc tells you what mapping to do via an '#error':
   // # error "Never use <bits/dlfcn.h> directly; include <dlfcn.h> instead."
@@ -488,7 +488,7 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/a.out.h>", kPrivate, "<a.out.h>", kPublic },
   { "<bits/byteswap-16.h>", kPrivate, "<byteswap.h>", kPublic },
   { "<bits/byteswap.h>", kPrivate, "<byteswap.h>", kPublic },
-  { "<bits/cmathcalls.h>", kPrivate, "<complex.h>", kPublic },
+  { "<bits/cmathcalls.h>", kPrivate, "<complex.h>", kPrivate },
   { "<bits/confname.h>", kPrivate, "<unistd.h>", kPublic },
   { "<bits/dirent.h>", kPrivate, "<dirent.h>", kPublic },
   { "<bits/dlfcn.h>", kPrivate, "<dlfcn.h>", kPublic },
@@ -498,38 +498,38 @@ const IncludeMapEntry libc_include_map[] = {
   { "<bits/eventfd.h>", kPrivate, "<sys/eventfd.h>", kPublic },
   { "<bits/fcntl-linux.h>", kPrivate, "<fcntl.h>", kPublic },
   { "<bits/fcntl.h>", kPrivate, "<fcntl.h>", kPublic },
-  { "<bits/fenv.h>", kPrivate, "<fenv.h>", kPublic },
-  { "<bits/huge_val.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/huge_valf.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/huge_vall.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/fenv.h>", kPrivate, "<fenv.h>", kPrivate },
+  { "<bits/huge_val.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/huge_valf.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/huge_vall.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/in.h>", kPrivate, "<netinet/in.h>", kPublic },
-  { "<bits/inf.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/inf.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/inotify.h>", kPrivate, "<sys/inotify.h>", kPublic },
   { "<bits/ioctl-types.h>", kPrivate, "<sys/ioctl.h>", kPublic },
   { "<bits/ioctls.h>", kPrivate, "<sys/ioctl.h>", kPublic },
   { "<bits/ipc.h>", kPrivate, "<sys/ipc.h>", kPublic },
   { "<bits/ipctypes.h>", kPrivate, "<sys/ipc.h>", kPublic },
-  { "<bits/locale.h>", kPrivate, "<locale.h>", kPublic },
-  { "<bits/math-finite.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/mathdef.h>", kPrivate, "<math.h>", kPublic },
-  { "<bits/mathinline.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/locale.h>", kPrivate, "<locale.h>", kPrivate },
+  { "<bits/math-finite.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/mathdef.h>", kPrivate, "<math.h>", kPrivate },
+  { "<bits/mathinline.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/mman-linux.h>", kPrivate, "<sys/mman.h>", kPublic },
   { "<bits/mman.h>", kPrivate, "<sys/mman.h>", kPublic },
   { "<bits/mqueue.h>", kPrivate, "<mqueue.h>", kPublic },
   { "<bits/msq.h>", kPrivate, "<sys/msg.h>", kPublic },
-  { "<bits/nan.h>", kPrivate, "<math.h>", kPublic },
+  { "<bits/nan.h>", kPrivate, "<math.h>", kPrivate },
   { "<bits/param.h>", kPrivate, "<sys/param.h>", kPublic },
   { "<bits/poll.h>", kPrivate, "<sys/poll.h>", kPrivate },
   { "<bits/predefs.h>", kPrivate, "<features.h>", kPublic },
   { "<bits/resource.h>", kPrivate, "<sys/resource.h>", kPublic },
   { "<bits/select.h>", kPrivate, "<sys/select.h>", kPublic },
   { "<bits/semaphore.h>", kPrivate, "<semaphore.h>", kPublic },
-  { "<bits/sigcontext.h>", kPrivate, "<signal.h>", kPublic },
+  { "<bits/sigcontext.h>", kPrivate, "<signal.h>", kPrivate },
   { "<bits/signalfd.h>", kPrivate, "<sys/signalfd.h>", kPublic },
-  { "<bits/stdlib-float.h>", kPrivate, "<stdlib.h>", kPublic },
-  { "<bits/string.h>", kPrivate, "<string.h>", kPublic },
-  { "<bits/string2.h>", kPrivate, "<string.h>", kPublic },
-  { "<bits/string3.h>", kPrivate, "<string.h>", kPublic },
+  { "<bits/stdlib-float.h>", kPrivate, "<stdlib.h>", kPrivate },
+  { "<bits/string.h>", kPrivate, "<string.h>", kPrivate },
+  { "<bits/string2.h>", kPrivate, "<string.h>", kPrivate },
+  { "<bits/string3.h>", kPrivate, "<string.h>", kPrivate },
   { "<bits/timerfd.h>", kPrivate, "<sys/timerfd.h>", kPublic },
   { "<bits/typesizes.h>", kPrivate, "<sys/types.h>", kPublic },
   // Top-level #includes that just forward to another file:
@@ -541,13 +541,13 @@ const IncludeMapEntry libc_include_map[] = {
   // on the POSIX.1-2024 list, I just choose the top-level one.
   { "<sys/aio.h>", kPrivate, "<aio.h>", kPublic },
   { "<sys/dirent.h>", kPrivate, "<dirent.h>", kPublic },
-  { "<sys/errno.h>", kPrivate, "<errno.h>", kPublic },
+  { "<sys/errno.h>", kPrivate, "<errno.h>", kPrivate },
   { "<sys/fcntl.h>", kPrivate, "<fcntl.h>", kPublic },
   { "<sys/poll.h>", kPrivate, "<poll.h>", kPublic },
   { "<sys/semaphore.h>", kPrivate, "<semaphore.h>", kPublic },
-  { "<sys/signal.h>", kPrivate, "<signal.h>", kPublic },
+  { "<sys/signal.h>", kPrivate, "<signal.h>", kPrivate },
   { "<sys/spawn.h>", kPrivate, "<spawn.h>", kPublic },
-  { "<sys/stdio.h>", kPrivate, "<stdio.h>", kPublic },
+  { "<sys/stdio.h>", kPrivate, "<stdio.h>", kPrivate },
   { "<sys/syslog.h>", kPrivate, "<syslog.h>", kPublic },
   { "<sys/termios.h>", kPrivate, "<termios.h>", kPublic },
   { "<sys/unistd.h>", kPrivate, "<unistd.h>", kPublic },
@@ -567,21 +567,21 @@ const IncludeMapEntry libc_include_map[] = {
   { "<asm/unistd_64.h>", kPrivate, "<asm/unistd.h>", kPrivate },
   // I don't know what grep would have found these.  I found them
   // via user report.
-  { "<asm/errno.h>", kPrivate, "<errno.h>", kPublic },
-  { "<asm/errno-base.h>", kPrivate, "<errno.h>", kPublic },
+  { "<asm/errno.h>", kPrivate, "<errno.h>", kPrivate },
+  { "<asm/errno-base.h>", kPrivate, "<errno.h>", kPrivate },
   { "<asm/ptrace-abi.h>", kPrivate, "<asm/ptrace.h>", kPublic },
   { "<asm/unistd.h>", kPrivate, "<sys/syscall.h>", kPublic },
-  { "<linux/limits.h>", kPrivate, "<limits.h>", kPublic },   // PATH_MAX
+  { "<linux/limits.h>", kPrivate, "<limits.h>", kPrivate },   // PATH_MAX
   { "<linux/prctl.h>", kPrivate, "<sys/prctl.h>", kPublic },
   { "<sys/ucontext.h>", kPrivate, "<ucontext.h>", kPublic },
   // System headers available on AIX, BSD, Solaris and other Unix systems
   { "<sys/dtrace.h>", kPrivate, "<dtrace.h>", kPublic },
   { "<sys/paths.h>", kPrivate, "<paths.h>", kPublic },
-  { "<sys/syslimits.h>", kPrivate, "<limits.h>", kPublic },
+  { "<sys/syslimits.h>", kPrivate, "<limits.h>", kPrivate },
   { "<sys/ttycom.h>", kPrivate, "<sys/ioctl.h>", kPublic },
   { "<sys/ustat.h>", kPrivate, "<ustat.h>", kPublic },
   // Exports guaranteed by the C standard
-  { "<stdint.h>", kPublic, "<inttypes.h>", kPublic },
+  { "<stdint.h>", kPrivate, "<inttypes.h>", kPrivate },
 };
 
 const IncludeMapEntry stdlib_c_include_map[] = {
@@ -601,31 +601,31 @@ const IncludeMapEntry stdlib_c_include_map[] = {
   //
   // $ curl -s -N https://raw.githubusercontent.com/cplusplus/draft/c%2B%2B20/source/lib-intro.tex | sed -n '/begin{multicolfloattable}.*{headers.cpp.c}/,/end{multicolfloattable}/p' | grep tcode | perl -nle 'm/tcode{<c(.*)>}/ && print qq@  { "<$1.h>", kPublic, "<c$1>", kPublic },@' | sort
   { "<assert.h>", kPublic, "<cassert>", kPublic },
-  { "<complex.h>", kPublic, "<ccomplex>", kPublic },
-  { "<ctype.h>", kPublic, "<cctype>", kPublic },
-  { "<errno.h>", kPublic, "<cerrno>", kPublic },
-  { "<fenv.h>", kPublic, "<cfenv>", kPublic },
-  { "<float.h>", kPublic, "<cfloat>", kPublic },
-  { "<inttypes.h>", kPublic, "<cinttypes>", kPublic },
-  { "<iso646.h>", kPublic, "<ciso646>", kPublic },
-  { "<limits.h>", kPublic, "<climits>", kPublic },
-  { "<locale.h>", kPublic, "<clocale>", kPublic },
-  { "<math.h>", kPublic, "<cmath>", kPublic },
-  { "<setjmp.h>", kPublic, "<csetjmp>", kPublic },
-  { "<signal.h>", kPublic, "<csignal>", kPublic },
-  { "<stdalign.h>", kPublic, "<cstdalign>", kPublic },
-  { "<stdarg.h>", kPublic, "<cstdarg>", kPublic },
-  { "<stdbool.h>", kPublic, "<cstdbool>", kPublic },
-  { "<stddef.h>", kPublic, "<cstddef>", kPublic },
-  { "<stdint.h>", kPublic, "<cstdint>", kPublic },
-  { "<stdio.h>", kPublic, "<cstdio>", kPublic },
-  { "<stdlib.h>", kPublic, "<cstdlib>", kPublic },
-  { "<string.h>", kPublic, "<cstring>", kPublic },
-  { "<tgmath.h>", kPublic, "<ctgmath>", kPublic },
-  { "<time.h>", kPublic, "<ctime>", kPublic },
-  { "<uchar.h>", kPublic, "<cuchar>", kPublic },
-  { "<wchar.h>", kPublic, "<cwchar>", kPublic },
-  { "<wctype.h>", kPublic, "<cwctype>", kPublic },
+  { "<complex.h>", kPrivate, "<ccomplex>", kPublic },
+  { "<ctype.h>", kPrivate, "<cctype>", kPublic },
+  { "<errno.h>", kPrivate, "<cerrno>", kPublic },
+  { "<fenv.h>", kPrivate, "<cfenv>", kPublic },
+  { "<float.h>", kPrivate, "<cfloat>", kPublic },
+  { "<inttypes.h>", kPrivate, "<cinttypes>", kPublic },
+  { "<iso646.h>", kPrivate, "<ciso646>", kPublic },
+  { "<limits.h>", kPrivate, "<climits>", kPublic },
+  { "<locale.h>", kPrivate, "<clocale>", kPublic },
+  { "<math.h>", kPrivate, "<cmath>", kPublic },
+  { "<setjmp.h>", kPrivate, "<csetjmp>", kPublic },
+  { "<signal.h>", kPrivate, "<csignal>", kPublic },
+  { "<stdalign.h>", kPrivate, "<cstdalign>", kPublic },
+  { "<stdarg.h>", kPrivate, "<cstdarg>", kPublic },
+  { "<stdbool.h>", kPrivate, "<cstdbool>", kPublic },
+  { "<stddef.h>", kPrivate, "<cstddef>", kPublic },
+  { "<stdint.h>", kPrivate, "<cstdint>", kPublic },
+  { "<stdio.h>", kPrivate, "<cstdio>", kPublic },
+  { "<stdlib.h>", kPrivate, "<cstdlib>", kPublic },
+  { "<string.h>", kPrivate, "<cstring>", kPublic },
+  { "<tgmath.h>", kPrivate, "<ctgmath>", kPublic },
+  { "<time.h>", kPrivate, "<ctime>", kPublic },
+  { "<uchar.h>", kPrivate, "<cuchar>", kPublic },
+  { "<wchar.h>", kPrivate, "<cwchar>", kPublic },
+  { "<wctype.h>", kPrivate, "<cwctype>", kPublic },
 };
 
 const char* stdlib_cpp_public_headers[] = {