diff --git a/README.md b/README.md
index 7114015..f0be759 100644
--- a/README.md
+++ b/README.md
@@ -211,13 +211,13 @@
 
     $ mma # In $ANDROID_ROOT/bionic.
     $ adb root && adb remount && adb sync
-    $ adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests32
+    $ adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests
     $ adb shell \
-        /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static32
+        /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static
     # Only for 64-bit targets
-    $ adb shell /data/nativetest64/bionic-unit-tests/bionic-unit-tests64
+    $ adb shell /data/nativetest64/bionic-unit-tests/bionic-unit-tests
     $ adb shell \
-        /data/nativetest64/bionic-unit-tests-static/bionic-unit-tests-static64
+        /data/nativetest64/bionic-unit-tests-static/bionic-unit-tests-static
 
 Note that we use our own custom gtest runner that offers a superset of the
 options documented at
@@ -286,7 +286,7 @@
     $ adb shell \
         GCOV_PREFIX=/data/local/tmp/gcov \
         GCOV_PREFIX_STRIP=`echo $ANDROID_BUILD_TOP | grep -o / | wc -l` \
-        /data/nativetest/bionic-unit-tests/bionic-unit-tests32
+        /data/nativetest/bionic-unit-tests/bionic-unit-tests
     $ acov
 
 `acov` will pull all coverage information from the device, push it to the right
diff --git a/benchmarks/stdio_benchmark.cpp b/benchmarks/stdio_benchmark.cpp
index 97a03dc..76e9ddb 100644
--- a/benchmarks/stdio_benchmark.cpp
+++ b/benchmarks/stdio_benchmark.cpp
@@ -196,3 +196,12 @@
   }
 }
 BIONIC_BENCHMARK(BM_stdio_printf_d);
+
+static void BM_stdio_printf_1$s(benchmark::State& state) {
+  while (state.KeepRunning()) {
+    char buf[BUFSIZ];
+    snprintf(buf, sizeof(buf), "this is a more typical error message with detail: %1$s",
+             "No such file or directory");
+  }
+}
+BIONIC_BENCHMARK(BM_stdio_printf_1$s);
diff --git a/benchmarks/suites/full.xml b/benchmarks/suites/full.xml
index 240b5e7..9bfd6ff 100644
--- a/benchmarks/suites/full.xml
+++ b/benchmarks/suites/full.xml
@@ -198,6 +198,9 @@
   <name>BM_stdio_printf_d</name>
 </fn>
 <fn>
+  <name>BM_stdio_printf_1$s</name>
+</fn>
+<fn>
   <name>BM_string_memcmp</name>
   <args>AT_ALIGNED_TWOBUF</args>
 </fn>
diff --git a/libc/Android.bp b/libc/Android.bp
index 27e90be..39bd2ec 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1969,17 +1969,13 @@
     defaults: ["linux_bionic_supported"],
     vendor_available: true,
 
-    no_default_compiler_flags: true,
-
-    cflags: ["-Wno-gcc-compat", "-Werror"],
+    cflags: ["-Wno-gcc-compat", "-Wall", "-Werror"],
 }
 
 cc_defaults {
     name: "crt_so_defaults",
+    defaults: ["crt_defaults"],
 
-    cflags: ["-Wno-gcc-compat", "-Werror"],
-
-    vendor_available: true,
     arch: {
         mips: {
             cflags: ["-fPIC"],
@@ -2008,10 +2004,7 @@
     },
     srcs: ["arch-common/bionic/crtbrand.S"],
 
-    defaults: [
-        "crt_defaults",
-        "crt_so_defaults",
-    ],
+    defaults: ["crt_so_defaults"],
 }
 
 cc_object {
@@ -2019,19 +2012,13 @@
     local_include_dirs: ["include"],
     srcs: ["arch-common/bionic/crtbegin_so.c"],
 
-    defaults: [
-        "crt_defaults",
-        "crt_so_defaults",
-    ],
+    defaults: ["crt_so_defaults"],
 }
 
 cc_object {
     name: "crtbegin_so",
 
-    defaults: [
-        "crt_defaults",
-        "crt_so_defaults",
-    ],
+    defaults: ["crt_so_defaults"],
     objs: [
         "crtbegin_so1",
         "crtbrand",
@@ -2043,10 +2030,7 @@
     local_include_dirs: ["include"],
     srcs: ["arch-common/bionic/crtend_so.S"],
 
-    defaults: [
-        "crt_defaults",
-        "crt_so_defaults",
-    ],
+    defaults: ["crt_so_defaults"],
 }
 
 cc_object {
@@ -2199,22 +2183,6 @@
 }
 
 ndk_headers {
-    name: "libc_asm_mips",
-    from: "kernel/uapi/asm-mips",
-    to: "mipsel-linux-android",
-    srcs: ["kernel/uapi/asm-mips/**/*.h"],
-    license: "NOTICE",
-}
-
-ndk_headers {
-    name: "libc_asm_mips64",
-    from: "kernel/uapi/asm-mips",
-    to: "mips64el-linux-android",
-    srcs: ["kernel/uapi/asm-mips/**/*.h"],
-    license: "NOTICE",
-}
-
-ndk_headers {
     name: "libc_asm_x86",
     from: "kernel/uapi/asm-x86",
     to: "i686-linux-android",
diff --git a/libc/include/android/legacy_fenv_inlines_arm.h b/libc/include/android/legacy_fenv_inlines_arm.h
index 58c49c2..de024cf 100644
--- a/libc/include/android/legacy_fenv_inlines_arm.h
+++ b/libc/include/android/legacy_fenv_inlines_arm.h
@@ -35,9 +35,6 @@
 
 __BEGIN_DECLS
 
-#define FPSCR_ENABLE_SHIFT 8
-#define FPSCR_ENABLE_MASK  (FE_ALL_EXCEPT << FPSCR_ENABLE_SHIFT)
-
 #define FPSCR_RMODE_SHIFT 22
 
 static __inline int fegetenv(fenv_t* __envp) {
@@ -108,7 +105,7 @@
   fenv_t __env;
   fegetenv(&__env);
   *__envp = __env;
-  __env &= ~(FE_ALL_EXCEPT | FPSCR_ENABLE_MASK);
+  __env &= ~FE_ALL_EXCEPT;
   fesetenv(&__env);
   return 0;
 }
@@ -121,30 +118,18 @@
   return 0;
 }
 
-static __inline int feenableexcept(int __mask) {
-  fenv_t __old_fpscr, __new_fpscr;
-  fegetenv(&__old_fpscr);
-  __new_fpscr = __old_fpscr | (__mask & FE_ALL_EXCEPT) << FPSCR_ENABLE_SHIFT;
-  fesetenv(&__new_fpscr);
-  return ((__old_fpscr >> FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
+static __inline int feenableexcept(int __mask __unused) {
+  return -1;
 }
 
-static __inline int fedisableexcept(int __mask) {
-  fenv_t __old_fpscr, __new_fpscr;
-  fegetenv(&__old_fpscr);
-  __new_fpscr = __old_fpscr & ~((__mask & FE_ALL_EXCEPT) << FPSCR_ENABLE_SHIFT);
-  fesetenv(&__new_fpscr);
-  return ((__old_fpscr >> FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
+static __inline int fedisableexcept(int __mask __unused) {
+  return 0;
 }
 
 static __inline int fegetexcept(void) {
-  fenv_t __fpscr;
-  fegetenv(&__fpscr);
-  return ((__fpscr & FPSCR_ENABLE_MASK) >> FPSCR_ENABLE_SHIFT);
+  return 0;
 }
 
-#undef FPSCR_ENABLE_SHIFT
-#undef FPSCR_ENABLE_MASK
 #undef FPSCR_RMODE_SHIFT
 
 __END_DECLS
diff --git a/libc/include/bits/fenv_arm.h b/libc/include/bits/fenv_arm.h
index 542ddbe..042fec3 100644
--- a/libc/include/bits/fenv_arm.h
+++ b/libc/include/bits/fenv_arm.h
@@ -26,13 +26,6 @@
  * $FreeBSD: src/lib/msun/arm/fenv.h,v 1.5 2005/03/16 19:03:45 das Exp $
  */
 
-/*
- * Rewritten for Android.
- *
- * The ARM FPSCR is described here:
- * http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0344b/Chdfafia.html
- */
-
 #ifndef _BITS_FENV_ARM_H_
 #define _BITS_FENV_ARM_H_
 
@@ -40,7 +33,28 @@
 
 __BEGIN_DECLS
 
+/*
+ * The ARM Cortex-A75 registers are described here:
+ *
+ * AArch64:
+ *  FPCR: http://infocenter.arm.com/help/topic/com.arm.doc.100403_0200_00_en/lau1442502503726.html
+ *  FPSR: http://infocenter.arm.com/help/topic/com.arm.doc.100403_0200_00_en/lau1442502526288.html
+ * AArch32:
+ *  FPSCR: http://infocenter.arm.com/help/topic/com.arm.doc.100403_0200_00_en/lau1442504290459.html
+ */
+
+#if defined(__LP64__)
+typedef struct {
+  /* FPCR, Floating-point Control Register. */
+  __uint32_t __control;
+  /* FPSR, Floating-point Status Register. */
+  __uint32_t __status;
+} fenv_t;
+
+#else
 typedef __uint32_t fenv_t;
+#endif
+
 typedef __uint32_t fexcept_t;
 
 /* Exception flags. */
@@ -49,8 +63,8 @@
 #define FE_OVERFLOW   0x04
 #define FE_UNDERFLOW  0x08
 #define FE_INEXACT    0x10
-#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
-                       FE_OVERFLOW | FE_UNDERFLOW)
+#define FE_DENORMAL   0x80
+#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW | FE_DENORMAL)
 
 /* Rounding modes. */
 #define FE_TONEAREST  0x0
diff --git a/libc/include/bits/fenv_arm64.h b/libc/include/bits/fenv_arm64.h
deleted file mode 100644
index 67f0fb4..0000000
--- a/libc/include/bits/fenv_arm64.h
+++ /dev/null
@@ -1,102 +0,0 @@
-/*-
- * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * $FreeBSD: src/lib/msun/arm/fenv.h,v 1.5 2005/03/16 19:03:45 das Exp $
- */
-
-/*
- * In ARMv8, AArch64 state, floating-point operation is controlled by:
- *
- *  * FPCR - 32Bit Floating-Point Control Register:
- *      * [31:27] - Reserved, Res0;
- *      * [26]    - AHP, Alternative half-precision control bit;
- *      * [25]    - DN, Default NaN mode control bit;
- *      * [24]    - FZ, Flush-to-zero mode control bit;
- *      * [23:22] - RMode, Rounding Mode control field:
- *            * 00  - Round to Nearest (RN) mode;
- *            * 01  - Round towards Plus Infinity (RP) mode;
- *            * 10  - Round towards Minus Infinity (RM) mode;
- *            * 11  - Round towards Zero (RZ) mode.
- *      * [21:20] - Stride, ignored during AArch64 execution;
- *      * [19]    - Reserved, Res0;
- *      * [18:16] - Len, ignored during AArch64 execution;
- *      * [15]    - IDE, Input Denormal exception trap;
- *      * [14:13] - Reserved, Res0;
- *      * [12]    - IXE, Inexact exception trap;
- *      * [11]    - UFE, Underflow exception trap;
- *      * [10]    - OFE, Overflow exception trap;
- *      * [9]     - DZE, Division by Zero exception;
- *      * [8]     - IOE, Invalid Operation exception;
- *      * [7:0]   - Reserved, Res0.
- *
- *  * FPSR - 32Bit Floating-Point Status Register:
- *      * [31]    - N, Negative condition flag for AArch32 (AArch64 sets PSTATE.N);
- *      * [30]    - Z, Zero condition flag for AArch32 (AArch64 sets PSTATE.Z);
- *      * [29]    - C, Carry conditon flag for AArch32 (AArch64 sets PSTATE.C);
- *      * [28]    - V, Overflow conditon flag for AArch32 (AArch64 sets PSTATE.V);
- *      * [27]    - QC, Cumulative saturation bit, Advanced SIMD only;
- *      * [26:8]  - Reserved, Res0;
- *      * [7]     - IDC, Input Denormal cumulative exception;
- *      * [6:5]   - Reserved, Res0;
- *      * [4]     - IXC, Inexact cumulative exception;
- *      * [3]     - UFC, Underflow cumulative exception;
- *      * [2]     - OFC, Overflow cumulative exception;
- *      * [1]     - DZC, Division by Zero cumulative exception;
- *      * [0]     - IOC, Invalid Operation cumulative exception.
- */
-
-#ifndef _BITS_FENV_ARM64_H_
-#define _BITS_FENV_ARM64_H_
-
-#include <sys/types.h>
-
-__BEGIN_DECLS
-
-typedef struct {
-  __uint32_t __control;     /* FPCR, Floating-point Control Register */
-  __uint32_t __status;      /* FPSR, Floating-point Status Register */
-} fenv_t;
-
-typedef __uint32_t fexcept_t;
-
-/* Exception flags. */
-#define FE_INVALID    0x01
-#define FE_DIVBYZERO  0x02
-#define FE_OVERFLOW   0x04
-#define FE_UNDERFLOW  0x08
-#define FE_INEXACT    0x10
-#define FE_DENORMAL   0x80
-#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
-                       FE_OVERFLOW | FE_UNDERFLOW | FE_DENORMAL)
-
-/* Rounding modes. */
-#define FE_TONEAREST  0x0
-#define FE_UPWARD     0x1
-#define FE_DOWNWARD   0x2
-#define FE_TOWARDZERO 0x3
-
-__END_DECLS
-
-#endif
diff --git a/libc/include/fenv.h b/libc/include/fenv.h
index 4276e87..2b607f5 100644
--- a/libc/include/fenv.h
+++ b/libc/include/fenv.h
@@ -32,9 +32,7 @@
 
 #include <sys/cdefs.h>
 
-#if defined(__aarch64__)
-#include <bits/fenv_arm64.h>
-#elif defined(__arm__)
+#if defined(__aarch64__) || defined(__arm__)
 #include <bits/fenv_arm.h>
 #elif defined(__i386__)
 #include <bits/fenv_x86.h>
diff --git a/libc/include/string.h b/libc/include/string.h
index d409ba8..226566c 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -63,11 +63,8 @@
 char* __strchr_chk(const char* __s, int __ch, size_t __n) __INTRODUCED_IN(18);
 #if defined(__USE_GNU)
 #if defined(__cplusplus)
-/* The versioner doesn't handle C++ blocks yet, so manually guarded. */
-#if __ANDROID_API__ >= 24
 extern "C++" char* strchrnul(char* __s, int __ch) __RENAME(strchrnul) __attribute_pure__ __INTRODUCED_IN(24);
 extern "C++" const char* strchrnul(const char* __s, int __ch) __RENAME(strchrnul) __attribute_pure__ __INTRODUCED_IN(24);
-#endif  /* __ANDROID_API__ >= 24 */
 #else
 char* strchrnul(const char* __s, int __ch) __attribute_pure__ __INTRODUCED_IN(24);
 #endif
@@ -136,11 +133,8 @@
  * It doesn't modify its argument, and in C++ it's const-correct.
  */
 #if defined(__cplusplus)
-/* The versioner doesn't handle C++ blocks yet, so manually guarded. */
-#if __ANDROID_API__ >= 23
 extern "C++" char* basename(char* __path) __RENAME(__gnu_basename) __INTRODUCED_IN(23);
 extern "C++" const char* basename(const char* __path) __RENAME(__gnu_basename) __INTRODUCED_IN(23);
-#endif  /* __ANDROID_API__ >= 23 */
 #else
 char* basename(const char* __path) __RENAME(__gnu_basename) __INTRODUCED_IN(23);
 #endif
diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp
index 46d717a..b4b2a36 100644
--- a/libc/stdio/stdio.cpp
+++ b/libc/stdio/stdio.cpp
@@ -581,7 +581,7 @@
 
 int fseeko64(FILE* fp, off64_t offset, int whence) {
   CHECK_FP(fp);
-  return __fseeko64(fp, offset, whence, 8*sizeof(off_t));
+  return __fseeko64(fp, offset, whence, 8*sizeof(off64_t));
 }
 
 int fsetpos(FILE* fp, const fpos_t* pos) {
diff --git a/libc/stdio/vfprintf.cpp b/libc/stdio/vfprintf.cpp
index 10303d9..366b196 100644
--- a/libc/stdio/vfprintf.cpp
+++ b/libc/stdio/vfprintf.cpp
@@ -251,7 +251,6 @@
 #define MAXINT 0x1000   /* largest integer size (intmax_t) */
 
 int __vfprintf(FILE* fp, const char* fmt0, __va_list ap) {
-  char* fmt;           /* format string */
   int ch;              /* character from fmt */
   int n, n2;           /* handy integers (short term usage) */
   char* cp;            /* handy char pointer (short term usage) */
@@ -261,7 +260,6 @@
   int width;           /* width from format (%8d), or 0 */
   int prec;            /* precision from format; <0 for N/A */
   char sign;           /* sign prefix (' ', '+', '-', or \0) */
-  wchar_t wc;
   mbstate_t ps;
   /*
    * We can decompose the printed representation of floating
@@ -316,10 +314,12 @@
    * below longer.
    */
 #define PADSIZE 16 /* pad chunk size */
-  static char blanks[PADSIZE] = { ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
-                                  ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' };
-  static char zeroes[PADSIZE] = { '0', '0', '0', '0', '0', '0', '0', '0',
-                                  '0', '0', '0', '0', '0', '0', '0', '0' };
+  static CHAR_TYPE blanks[PADSIZE] = {
+    ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '
+  };
+  static CHAR_TYPE zeroes[PADSIZE] = {
+    '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0'
+  };
 
   static const char xdigs_lower[] = "0123456789abcdef";
   static const char xdigs_upper[] = "0123456789ABCDEF";
@@ -444,17 +444,19 @@
   ((argtable != NULL) ? *((type*)(&argtable[nextarg++])) : (nextarg++, va_arg(ap, type)))
 
   _SET_ORIENTATION(fp, -1);
-  /* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
+
+  // Writing "" to a read only file returns EOF, not 0.
   if (cantwrite(fp)) {
     errno = EBADF;
-    return (EOF);
+    return EOF;
   }
 
-  /* optimise fprintf(stderr) (and other unbuffered Unix files) */
-  if ((fp->_flags & (__SNBF | __SWR | __SRW)) == (__SNBF | __SWR) && fp->_file >= 0)
+  // Optimize writes to stderr and other unbuffered files).
+  if ((fp->_flags & (__SNBF | __SWR | __SRW)) == (__SNBF | __SWR) && fp->_file >= 0) {
     return (__sbprintf(fp, fmt0, ap));
+  }
 
-  fmt = (char*)fmt0;
+  CHAR_TYPE* fmt = const_cast<CHAR_TYPE*>(fmt0);
   argtable = NULL;
   nextarg = 1;
   va_copy(orgap, ap);
@@ -469,25 +471,14 @@
    * Scan the format for conversions (`%' character).
    */
   for (;;) {
-    cp = fmt;
-    while ((n = mbrtowc(&wc, fmt, MB_CUR_MAX, &ps)) > 0) {
-      fmt += n;
-      if (wc == '%') {
-        fmt--;
-        break;
-      }
-    }
-    if (n < 0) {
-      ret = -1;
-      goto error;
-    }
+    for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++) continue;
     if (fmt != cp) {
       ptrdiff_t m = fmt - cp;
       if (m < 0 || m > INT_MAX - ret) goto overflow;
       PRINT(cp, m);
       ret += m;
     }
-    if (n == 0) goto done;
+    if (ch == '\0') goto done;
     fmt++; /* skip over '%' */
 
     flags = 0;
@@ -1062,12 +1053,10 @@
  * used since we are attempting to make snprintf thread safe, and alloca is
  * problematic since we have nested functions..)
  */
-static int __find_arguments(const char* fmt0, va_list ap, union arg** argtable,
+static int __find_arguments(const CHAR_TYPE* fmt0, va_list ap, union arg** argtable,
                             size_t* argtablesiz) {
-  char* fmt;                /* format string */
   int ch;                   /* character from fmt */
   int n, n2;                /* handy integer (short term usage) */
-  char* cp;                 /* handy char pointer (short term usage) */
   int flags;                /* flags as above */
   unsigned char* typetable; /* table of types */
   unsigned char stattypetable[STATIC_ARG_TBL_SIZE];
@@ -1075,8 +1064,6 @@
   int tablemax;  /* largest used index in table */
   int nextarg;   /* 1-based argument index */
   int ret = 0;   /* return value */
-  wchar_t wc;
-  mbstate_t ps;
 
   /*
    * Add an argument type to the table, expanding if necessary.
@@ -1135,28 +1122,20 @@
   } else {                 \
     ADDTYPE(T_INT);        \
   }
-  fmt = (char*)fmt0;
+  CHAR_TYPE* fmt = const_cast<CHAR_TYPE*>(fmt0);
+  CHAR_TYPE* cp;
   typetable = stattypetable;
   tablesize = STATIC_ARG_TBL_SIZE;
   tablemax = 0;
   nextarg = 1;
   memset(typetable, T_UNUSED, STATIC_ARG_TBL_SIZE);
-  memset(&ps, 0, sizeof(ps));
 
   /*
    * Scan the format for conversions (`%' character).
    */
   for (;;) {
-    cp = fmt;
-    while ((n = mbrtowc(&wc, fmt, MB_CUR_MAX, &ps)) > 0) {
-      fmt += n;
-      if (wc == '%') {
-        fmt--;
-        break;
-      }
-    }
-    if (n < 0) return (-1);
-    if (n == 0) goto done;
+    for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++) continue;
+    if (ch == '\0') goto done;
     fmt++; /* skip over '%' */
 
     flags = 0;
diff --git a/libc/stdio/vfwprintf.cpp b/libc/stdio/vfwprintf.cpp
index 38acccf..7235969 100644
--- a/libc/stdio/vfwprintf.cpp
+++ b/libc/stdio/vfwprintf.cpp
@@ -277,7 +277,6 @@
 #define MAXINT 0x1000   /* largest integer size (intmax_t) */
 
 int __vfwprintf(FILE* __restrict fp, const wchar_t* __restrict fmt0, __va_list ap) {
-  wchar_t* fmt;  /* format string */
   wchar_t ch;    /* character from fmt */
   int n, n2, n3; /* handy integers (short term usage) */
   wchar_t* cp;   /* handy char pointer (short term usage) */
@@ -336,10 +335,12 @@
    * below longer.
    */
 #define PADSIZE 16 /* pad chunk size */
-  static wchar_t blanks[PADSIZE] = { ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
-                                     ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' };
-  static wchar_t zeroes[PADSIZE] = { '0', '0', '0', '0', '0', '0', '0', '0',
-                                     '0', '0', '0', '0', '0', '0', '0', '0' };
+  static CHAR_TYPE blanks[PADSIZE] = {
+    ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '
+  };
+  static CHAR_TYPE zeroes[PADSIZE] = {
+    '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0'
+  };
 
   static const char xdigs_lower[] = "0123456789abcdef";
   static const char xdigs_upper[] = "0123456789ABCDEF";
@@ -421,25 +422,28 @@
    * Get * arguments, including the form *nn$.  Preserve the nextarg
    * that the argument can be gotten once the type is determined.
    */
-#define GETASTER(val)                                         \
-  n2 = 0;                                                     \
-  cp = fmt;                                                   \
-  while (is_digit(*cp)) {                                     \
-    APPEND_DIGIT(n2, *cp);                                    \
-    cp++;                                                     \
-  }                                                           \
-  if (*cp == '$') {                                           \
-    int hold = nextarg;                                       \
-    if (argtable == NULL) {                                   \
-      argtable = statargtable;                                \
-      __find_arguments(fmt0, orgap, &argtable, &argtablesiz); \
-    }                                                         \
-    nextarg = n2;                                             \
-    val = GETARG(int);                                        \
-    nextarg = hold;                                           \
-    fmt = ++cp;                                               \
-  } else {                                                    \
-    val = GETARG(int);                                        \
+#define GETASTER(val)                                                     \
+  n2 = 0;                                                                 \
+  cp = fmt;                                                               \
+  while (is_digit(*cp)) {                                                 \
+    APPEND_DIGIT(n2, *cp);                                                \
+    cp++;                                                                 \
+  }                                                                       \
+  if (*cp == '$') {                                                       \
+    int hold = nextarg;                                                   \
+    if (argtable == NULL) {                                               \
+      argtable = statargtable;                                            \
+      if (__find_arguments(fmt0, orgap, &argtable, &argtablesiz) == -1) { \
+        ret = -1;                                                         \
+        goto error;                                                       \
+      }                                                                   \
+    }                                                                     \
+    nextarg = n2;                                                         \
+    val = GETARG(int);                                                    \
+    nextarg = hold;                                                       \
+    fmt = ++cp;                                                           \
+  } else {                                                                \
+    val = GETARG(int);                                                    \
   }
 
 /*
@@ -451,17 +455,19 @@
   ((argtable != NULL) ? *((type*)(&argtable[nextarg++])) : (nextarg++, va_arg(ap, type)))
 
   _SET_ORIENTATION(fp, 1);
-  /* sorry, fwprintf(read_only_file, "") returns EOF, not 0 */
+
+  // Writing "" to a read only file returns EOF, not 0.
   if (cantwrite(fp)) {
     errno = EBADF;
-    return (EOF);
+    return EOF;
   }
 
-  /* optimise fwprintf(stderr) (and other unbuffered Unix files) */
-  if ((fp->_flags & (__SNBF | __SWR | __SRW)) == (__SNBF | __SWR) && fp->_file >= 0)
+  // Optimize writes to stderr and other unbuffered files).
+  if ((fp->_flags & (__SNBF | __SWR | __SRW)) == (__SNBF | __SWR) && fp->_file >= 0) {
     return (__sbprintf(fp, fmt0, ap));
+  }
 
-  fmt = (wchar_t*)fmt0;
+  CHAR_TYPE* fmt = const_cast<CHAR_TYPE*>(fmt0);
   argtable = NULL;
   nextarg = 1;
   va_copy(orgap, ap);
@@ -540,7 +546,10 @@
           nextarg = n;
           if (argtable == NULL) {
             argtable = statargtable;
-            __find_arguments(fmt0, orgap, &argtable, &argtablesiz);
+            if (__find_arguments(fmt0, orgap, &argtable, &argtablesiz) == -1) {
+              ret = -1;
+              goto error;
+            }
           }
           goto rflag;
         }
@@ -572,7 +581,10 @@
           nextarg = n;
           if (argtable == NULL) {
             argtable = statargtable;
-            __find_arguments(fmt0, orgap, &argtable, &argtablesiz);
+            if (__find_arguments(fmt0, orgap, &argtable, &argtablesiz) == -1) {
+              ret = -1;
+              goto error;
+            }
           }
           goto rflag;
         }
@@ -1037,12 +1049,10 @@
  * used since we are attempting to make snprintf thread safe, and alloca is
  * problematic since we have nested functions..)
  */
-static int __find_arguments(const wchar_t* fmt0, va_list ap, union arg** argtable,
+static int __find_arguments(const CHAR_TYPE* fmt0, va_list ap, union arg** argtable,
                             size_t* argtablesiz) {
-  wchar_t* fmt;             /* format string */
   int ch;                   /* character from fmt */
   int n, n2;                /* handy integer (short term usage) */
-  wchar_t* cp;              /* handy char pointer (short term usage) */
   int flags;                /* flags as above */
   unsigned char* typetable; /* table of types */
   unsigned char stattypetable[STATIC_ARG_TBL_SIZE];
@@ -1108,7 +1118,8 @@
   } else {                 \
     ADDTYPE(T_INT);        \
   }
-  fmt = (wchar_t*)fmt0;
+  CHAR_TYPE* fmt = const_cast<CHAR_TYPE*>(fmt0);
+  CHAR_TYPE* cp;
   typetable = stattypetable;
   tablesize = STATIC_ARG_TBL_SIZE;
   tablemax = 0;
diff --git a/libm/arm/fenv.c b/libm/arm/fenv.c
index 2124730..c988e4f 100644
--- a/libm/arm/fenv.c
+++ b/libm/arm/fenv.c
@@ -28,9 +28,6 @@
 
 #include <fenv.h>
 
-#define FPSCR_ENABLE_SHIFT 8
-#define FPSCR_ENABLE_MASK  (FE_ALL_EXCEPT << FPSCR_ENABLE_SHIFT)
-
 #define FPSCR_RMODE_SHIFT 22
 
 const fenv_t __fe_dfl_env = 0;
@@ -103,7 +100,7 @@
   fenv_t __env;
   fegetenv(&__env);
   *__envp = __env;
-  __env &= ~(FE_ALL_EXCEPT | FPSCR_ENABLE_MASK);
+  __env &= ~FE_ALL_EXCEPT;
   fesetenv(&__env);
   return 0;
 }
@@ -116,24 +113,14 @@
   return 0;
 }
 
-int feenableexcept(int __mask) {
-  fenv_t __old_fpscr, __new_fpscr;
-  fegetenv(&__old_fpscr);
-  __new_fpscr = __old_fpscr | (__mask & FE_ALL_EXCEPT) << FPSCR_ENABLE_SHIFT;
-  fesetenv(&__new_fpscr);
-  return ((__old_fpscr >> FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
+int feenableexcept(int __mask __unused) {
+  return -1;
 }
 
-int fedisableexcept(int __mask) {
-  fenv_t __old_fpscr, __new_fpscr;
-  fegetenv(&__old_fpscr);
-  __new_fpscr = __old_fpscr & ~((__mask & FE_ALL_EXCEPT) << FPSCR_ENABLE_SHIFT);
-  fesetenv(&__new_fpscr);
-  return ((__old_fpscr >> FPSCR_ENABLE_SHIFT) & FE_ALL_EXCEPT);
+int fedisableexcept(int __mask __unused) {
+  return 0;
 }
 
 int fegetexcept(void) {
-  fenv_t __fpscr;
-  fegetenv(&__fpscr);
-  return ((__fpscr & FPSCR_ENABLE_MASK) >> FPSCR_ENABLE_SHIFT);
+  return 0;
 }
diff --git a/libm/arm64/fenv.c b/libm/arm64/fenv.c
index 19a2393..a99288b 100644
--- a/libm/arm64/fenv.c
+++ b/libm/arm64/fenv.c
@@ -29,9 +29,6 @@
 #include <stdint.h>
 #include <fenv.h>
 
-#define FPCR_EXCEPT_SHIFT 8
-#define FPCR_EXCEPT_MASK  (FE_ALL_EXCEPT << FPCR_EXCEPT_SHIFT)
-
 #define FPCR_RMODE_SHIFT 22
 
 const fenv_t __fe_dfl_env = { 0 /* control */, 0 /* status */};
@@ -137,22 +134,13 @@
 }
 
 int feholdexcept(fenv_t* envp) {
-  fenv_t env;
   fpu_status_t fpsr;
-  fpu_control_t fpcr, new_fpcr;
-
   __get_fpsr(fpsr);
+  fpu_control_t fpcr;
   __get_fpcr(fpcr);
-  env.__status = fpsr;
-  env.__control = fpcr;
+  fenv_t env = { .__status = fpsr, .__control = fpcr };
   *envp = env;
 
-  // Set exceptions to untrapped.
-  new_fpcr = fpcr & ~(FE_ALL_EXCEPT << FPCR_EXCEPT_SHIFT);
-  if (new_fpcr != fpcr) {
-    __set_fpcr(new_fpcr);
-  }
-
   // Clear all exceptions.
   fpsr &= ~FE_ALL_EXCEPT;
   __set_fpsr(fpsr);
@@ -176,31 +164,14 @@
   return 0;
 }
 
-int feenableexcept(int mask) {
-  fpu_control_t old_fpcr, new_fpcr;
-
-  __get_fpcr(old_fpcr);
-  new_fpcr = old_fpcr | ((mask & FE_ALL_EXCEPT) << FPCR_EXCEPT_SHIFT);
-  if (new_fpcr != old_fpcr) {
-    __set_fpcr(new_fpcr);
-  }
-  return ((old_fpcr >> FPCR_EXCEPT_SHIFT) & FE_ALL_EXCEPT);
+int feenableexcept(int mask __unused) {
+  return -1;
 }
 
-int fedisableexcept(int mask) {
-  fpu_control_t old_fpcr, new_fpcr;
-
-  __get_fpcr(old_fpcr);
-  new_fpcr = old_fpcr & ~((mask & FE_ALL_EXCEPT) << FPCR_EXCEPT_SHIFT);
-  if (new_fpcr != old_fpcr) {
-    __set_fpcr(new_fpcr);
-  }
-  return ((old_fpcr >> FPCR_EXCEPT_SHIFT) & FE_ALL_EXCEPT);
+int fedisableexcept(int mask __unused) {
+  return 0;
 }
 
 int fegetexcept(void) {
-  fpu_control_t fpcr;
-
-  __get_fpcr(fpcr);
-  return ((fpcr & FPCR_EXCEPT_MASK) >> FPCR_EXCEPT_SHIFT);
+  return 0;
 }
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 697b84a..6bd6e0c 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -24,6 +24,7 @@
 #if __has_include(<sys/auxv.h>)
 #include <sys/auxv.h>
 #endif
+#include <sys/user.h>
 
 #include <string>
 #include <thread>
@@ -824,6 +825,21 @@
 #endif
 }
 
+TEST(dlfcn, dlclose_unload) {
+  void* handle = dlopen("libtest_simple.so", RTLD_NOW);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+  uint32_t* taxicab_number = static_cast<uint32_t*>(dlsym(handle, "dlopen_testlib_taxicab_number"));
+  ASSERT_TRUE(taxicab_number != nullptr) << dlerror();
+  EXPECT_EQ(1729U, *taxicab_number);
+  dlclose(handle);
+  // Making sure that the library has been unmapped as part of library unload
+  // process. Note that mprotect somewhat counter-intuitively returns ENOMEM in
+  // this case.
+  uintptr_t page_start = reinterpret_cast<uintptr_t>(taxicab_number) & ~(PAGE_SIZE - 1);
+  ASSERT_TRUE(mprotect(reinterpret_cast<void*>(page_start), PAGE_SIZE, PROT_NONE) != 0);
+  ASSERT_EQ(ENOMEM, errno) << strerror(errno);
+}
+
 static void ConcurrentDlErrorFn(std::string& error) {
   ASSERT_TRUE(dlerror() == nullptr);
 
@@ -1102,17 +1118,17 @@
 
 // Check that RTLD_NEXT of a libc symbol works in dlopened library
 TEST(dlfcn, rtld_next_from_library) {
-  void* library_with_close = dlopen("libtest_check_rtld_next_from_library.so", RTLD_NOW);
-  ASSERT_TRUE(library_with_close != nullptr) << dlerror();
-  void* expected_addr = dlsym(RTLD_DEFAULT, "close");
+  void* library_with_fclose = dlopen("libtest_check_rtld_next_from_library.so", RTLD_NOW);
+  ASSERT_TRUE(library_with_fclose != nullptr) << dlerror();
+  void* expected_addr = dlsym(RTLD_DEFAULT, "fclose");
   ASSERT_TRUE(expected_addr != nullptr) << dlerror();
-  typedef void* (*get_libc_close_ptr_fn_t)();
-  get_libc_close_ptr_fn_t get_libc_close_ptr =
-      reinterpret_cast<get_libc_close_ptr_fn_t>(dlsym(library_with_close, "get_libc_close_ptr"));
-  ASSERT_TRUE(get_libc_close_ptr != nullptr) << dlerror();
-  ASSERT_EQ(expected_addr, get_libc_close_ptr());
+  typedef void* (*get_libc_fclose_ptr_fn_t)();
+  get_libc_fclose_ptr_fn_t get_libc_fclose_ptr =
+      reinterpret_cast<get_libc_fclose_ptr_fn_t>(dlsym(library_with_fclose, "get_libc_fclose_ptr"));
+  ASSERT_TRUE(get_libc_fclose_ptr != nullptr) << dlerror();
+  ASSERT_EQ(expected_addr, get_libc_fclose_ptr());
 
-  dlclose(library_with_close);
+  dlclose(library_with_fclose);
 }
 
 
diff --git a/tests/fenv_test.cpp b/tests/fenv_test.cpp
index c914692..9fc7d96 100644
--- a/tests/fenv_test.cpp
+++ b/tests/fenv_test.cpp
@@ -182,12 +182,20 @@
 
 TEST(fenv, feenableexcept_fegetexcept) {
 #if defined(__aarch64__) || defined(__arm__)
-  // Unsupported.
-  // arm:
-  // http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100403_0200_00_en/lau1442504290459.html
-  // aarch64:
-  // http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0488h/way1382990760439.html
-  GTEST_LOG_(INFO) << "arm and arm64 don't support feenableexcept";
+  // ARM doesn't support this. They used to if you go back far enough, but it was removed in
+  // the Cortex-A8 between r3p1 and r3p2.
+  ASSERT_EQ(-1, feenableexcept(FE_INVALID));
+  ASSERT_EQ(0, fegetexcept());
+  ASSERT_EQ(-1, feenableexcept(FE_DIVBYZERO));
+  ASSERT_EQ(0, fegetexcept());
+  ASSERT_EQ(-1, feenableexcept(FE_OVERFLOW));
+  ASSERT_EQ(0, fegetexcept());
+  ASSERT_EQ(-1, feenableexcept(FE_UNDERFLOW));
+  ASSERT_EQ(0, fegetexcept());
+  ASSERT_EQ(-1, feenableexcept(FE_INEXACT));
+  ASSERT_EQ(0, fegetexcept());
+  ASSERT_EQ(-1, feenableexcept(FE_DENORMAL));
+  ASSERT_EQ(0, fegetexcept());
 #else
   // We can't recover from SIGFPE, so sacrifice a child...
   pid_t pid = fork();
diff --git a/tests/libs/check_rtld_next_from_library.cpp b/tests/libs/check_rtld_next_from_library.cpp
index 45d8eea..fb15e2a 100644
--- a/tests/libs/check_rtld_next_from_library.cpp
+++ b/tests/libs/check_rtld_next_from_library.cpp
@@ -15,22 +15,23 @@
  */
 
 #include <dlfcn.h>
+#include <stdio.h>
 #include <stdlib.h>
 
-static void* g_libc_close_ptr;
+static void* g_libc_fclose_ptr;
 
-static void __attribute__((constructor)) __libc_close_lookup() {
-  g_libc_close_ptr = dlsym(RTLD_NEXT, "close");
+static void __attribute__((constructor)) __libc_fclose_lookup() {
+  g_libc_fclose_ptr = dlsym(RTLD_NEXT, "fclose");
 }
 
-// A libc function used for RTLD_NEXT
-// This function in not supposed to be called
-extern "C" int __attribute__((weak)) close(int) {
+// A libc function used for RTLD_NEXT.
+// This function in not supposed to be called.
+extern "C" int __attribute__((weak)) fclose(FILE*) {
   abort();
 }
 
-extern "C" void* get_libc_close_ptr() {
-  return g_libc_close_ptr;
+extern "C" void* get_libc_fclose_ptr() {
+  return g_libc_fclose_ptr;
 }
 
 
diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index 87a0eae..05a19d1 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -2148,3 +2148,37 @@
 
   ASSERT_EQ(0, fclose(fp));
 }
+
+TEST(STDIO_TEST, fseek_64bit) {
+  TemporaryFile tf;
+  FILE* fp = fopen64(tf.filename, "w+");
+  ASSERT_TRUE(fp != nullptr);
+  ASSERT_EQ(0, fseeko64(fp, 0x2'0000'0000, SEEK_SET));
+  ASSERT_EQ(0x2'0000'0000, ftello64(fp));
+  ASSERT_EQ(0, fseeko64(fp, 0x1'0000'0000, SEEK_CUR));
+  ASSERT_EQ(0x3'0000'0000, ftello64(fp));
+  ASSERT_EQ(0, fclose(fp));
+}
+
+// POSIX requires that fseek/fseeko fail with EOVERFLOW if the new file offset
+// isn't representable in long/off_t.
+TEST(STDIO_TEST, fseek_overflow_32bit) {
+  TemporaryFile tf;
+  FILE* fp = fopen64(tf.filename, "w+");
+  ASSERT_EQ(0, ftruncate64(fileno(fp), 0x2'0000'0000));
+
+  // Bionic implements overflow checking for SEEK_CUR, but glibc doesn't.
+#if defined(__BIONIC__) && !defined(__LP64__)
+  ASSERT_EQ(0, fseek(fp, 0x7fff'ffff, SEEK_SET));
+  ASSERT_EQ(-1, fseek(fp, 1, SEEK_CUR));
+  ASSERT_EQ(EOVERFLOW, errno);
+#endif
+
+  // Neither Bionic nor glibc implement the overflow checking for SEEK_END.
+  // (Aside: FreeBSD's libc is an example of a libc that checks both SEEK_CUR
+  // and SEEK_END -- many C libraries check neither.)
+  ASSERT_EQ(0, fseek(fp, 0, SEEK_END));
+  ASSERT_EQ(0x2'0000'0000, ftello64(fp));
+
+  fclose(fp);
+}
diff --git a/tools/versioner/src/DeclarationDatabase.cpp b/tools/versioner/src/DeclarationDatabase.cpp
index 4443834..19c2f0d 100644
--- a/tools/versioner/src/DeclarationDatabase.cpp
+++ b/tools/versioner/src/DeclarationDatabase.cpp
@@ -90,7 +90,7 @@
     return "<unnamed>";
   }
 
-  bool VisitDecl(Decl* decl) {
+  bool VisitDeclaratorDecl(DeclaratorDecl* decl, SourceRange range) {
     // Skip declarations inside of functions (function arguments, variable declarations inside of
     // inline functions, etc).
     if (decl->getParentFunctionOrMethod()) {
@@ -143,21 +143,6 @@
       return true;
     }
 
-    auto start_loc = src_manager.getPresumedLoc(decl->getLocStart());
-    auto end_loc = src_manager.getPresumedLoc(decl->getLocEnd());
-
-    Location location = {
-      .filename = start_loc.getFilename(),
-      .start = {
-        .line = start_loc.getLine(),
-        .column = start_loc.getColumn(),
-      },
-      .end = {
-        .line = end_loc.getLine(),
-        .column = end_loc.getColumn(),
-      }
-    };
-
     DeclarationAvailability availability;
 
     // Find and parse __ANDROID_AVAILABILITY_DUMP__ annotations.
@@ -215,6 +200,24 @@
       std::tie(symbol_it, dummy) = database.symbols.insert({ declaration_name, symbol });
     }
 
+    auto expansion_range = src_manager.getExpansionRange(range);
+    auto filename = src_manager.getFilename(expansion_range.getBegin());
+    if (filename != src_manager.getFilename(expansion_range.getEnd())) {
+      errx(1, "expansion range filenames don't match");
+    }
+
+    Location location = {
+      .filename = filename,
+      .start = {
+        .line = src_manager.getExpansionLineNumber(expansion_range.getBegin()),
+        .column = src_manager.getExpansionColumnNumber(expansion_range.getBegin()),
+      },
+      .end = {
+        .line = src_manager.getExpansionLineNumber(expansion_range.getEnd()),
+        .column = src_manager.getExpansionColumnNumber(expansion_range.getEnd()),
+      }
+    };
+
     // Find or insert an entry for the declaration.
     if (auto declaration_it = symbol_it->second.declarations.find(location);
         declaration_it != symbol_it->second.declarations.end()) {
@@ -238,6 +241,38 @@
 
     return true;
   }
+
+  bool VisitDeclaratorDecl(DeclaratorDecl* decl) {
+    return VisitDeclaratorDecl(decl, decl->getSourceRange());
+  }
+
+  bool TraverseLinkageSpecDecl(LinkageSpecDecl* decl) {
+    // Make sure that we correctly calculate the SourceRange of a declaration that has a non-braced
+    // extern "C"/"C++".
+    if (!decl->hasBraces()) {
+      DeclaratorDecl* child = nullptr;
+      for (auto child_decl : decl->decls()) {
+        if (child != nullptr) {
+          errx(1, "LinkageSpecDecl has multiple children");
+        }
+
+        if (DeclaratorDecl* declarator_decl = dyn_cast<DeclaratorDecl>(child_decl)) {
+          child = declarator_decl;
+        } else {
+          errx(1, "child of LinkageSpecDecl is not a DeclaratorDecl");
+        }
+      }
+
+      return VisitDeclaratorDecl(child, decl->getSourceRange());
+    }
+
+    for (auto child : decl->decls()) {
+      if (!TraverseDecl(child)) {
+        return false;
+      }
+    }
+    return true;
+  }
 };
 
 bool DeclarationAvailability::merge(const DeclarationAvailability& other) {
diff --git a/tools/versioner/tests/preprocessor_extern_cpp/expected/foo.h b/tools/versioner/tests/preprocessor_extern_cpp/expected/foo.h
new file mode 100644
index 0000000..9b2d122
--- /dev/null
+++ b/tools/versioner/tests/preprocessor_extern_cpp/expected/foo.h
@@ -0,0 +1,27 @@
+#define __RENAME(x) asm(#x)
+
+#if defined(__cplusplus)
+
+#if __ANDROID_API__ >= 24
+extern "C++" const char* strchrnul(const char*, int) __RENAME(strchrnul) __INTRODUCED_IN(24);
+#endif /* __ANDROID_API__ >= 24 */
+
+#endif
+
+#if defined(__cplusplus)
+extern "C" int foo();
+#endif
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+#if __ANDROID_API__ >= 24
+char* strchrnul(char*, int) __INTRODUCED_IN(24);
+#endif /* __ANDROID_API__ >= 24 */
+
+
+#if defined(__cplusplus)
+}
+#endif
diff --git a/tools/versioner/tests/preprocessor_extern_cpp/headers/foo.h b/tools/versioner/tests/preprocessor_extern_cpp/headers/foo.h
new file mode 100644
index 0000000..de26d21
--- /dev/null
+++ b/tools/versioner/tests/preprocessor_extern_cpp/headers/foo.h
@@ -0,0 +1,19 @@
+#define __RENAME(x) asm(#x)
+
+#if defined(__cplusplus)
+extern "C++" const char* strchrnul(const char*, int) __RENAME(strchrnul) __INTRODUCED_IN(24);
+#endif
+
+#if defined(__cplusplus)
+extern "C" int foo();
+#endif
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+char* strchrnul(char*, int) __INTRODUCED_IN(24);
+
+#if defined(__cplusplus)
+}
+#endif
diff --git a/tools/versioner/tests/preprocessor_extern_cpp/platforms/android-9/arch-arm/symbols/libc.so.functions.txt b/tools/versioner/tests/preprocessor_extern_cpp/platforms/android-9/arch-arm/symbols/libc.so.functions.txt
new file mode 100644
index 0000000..257cc56
--- /dev/null
+++ b/tools/versioner/tests/preprocessor_extern_cpp/platforms/android-9/arch-arm/symbols/libc.so.functions.txt
@@ -0,0 +1 @@
+foo
diff --git a/tools/versioner/tests/preprocessor_extern_cpp/run.sh b/tools/versioner/tests/preprocessor_extern_cpp/run.sh
new file mode 100644
index 0000000..50d9b5c
--- /dev/null
+++ b/tools/versioner/tests/preprocessor_extern_cpp/run.sh
@@ -0,0 +1,29 @@
+set -e
+
+function run_test {
+  SRC=$1
+  DST=$2
+  rm -rf $2
+  versioner -a 9 -a 12 -a 13 -a 14 -a 15 $1 -i -o $2
+  diff -q -w -B $2 expected
+}
+
+run_test headers out
+run_test headers/ out
+run_test headers out/
+run_test headers/ out/
+
+run_test `pwd`/headers out
+run_test `pwd`/headers/ out
+run_test `pwd`/headers out/
+run_test `pwd`/headers/ out/
+
+run_test headers `pwd`/out
+run_test headers/ `pwd`/out
+run_test headers `pwd`/out/
+run_test headers/ `pwd`/out/
+
+run_test `pwd`/headers `pwd`/out
+run_test `pwd`/headers/ `pwd`/out
+run_test `pwd`/headers `pwd`/out/
+run_test `pwd`/headers/ `pwd`/out/