hg merge default to release-1.15

31 files changed, 424 insertions, 84 deletions

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index b26dfec..d30f9b0 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -33,6 +33,7 @@ jobs:
         - spec: cp38-manylinux_x86_64
         - spec: cp39-manylinux_x86_64
         - spec: cp310-manylinux_x86_64
+        - spec: cp311-manylinux_x86_64
         - spec: cp27-manylinux_i686
           cibw_version: cibuildwheel<2.0  # py2.7 is not supported on CIBW 2.0+
           manylinux_img: manylinux1  # build really old Pythons on manylinux1
@@ -42,12 +43,20 @@ jobs:
         - spec: cp38-manylinux_i686
         - spec: cp39-manylinux_i686
         - spec: cp310-manylinux_i686
+        - spec: cp311-manylinux_i686
+        - spec: cp39-musllinux_x86_64
+        - spec: cp310-musllinux_x86_64
+        - spec: cp311-musllinux_x86_64
+        - spec: cp39-musllinux_i686
+        - spec: cp310-musllinux_i686
+        - spec: cp311-musllinux_i686
     steps:
     - name: clone repo
       uses: actions/checkout@v2
 
     - name: build/test wheels
       env:
+        CFLAGS: -Dffi_call=cffistatic_ffi_call  # override name for ffi_call to break hard if we linked against someone else's libffi
         CIBW_ARCHS_LINUX: auto
         CIBW_BUILD: ${{ matrix.spec }}
         CIBW_BEFORE_BUILD: |
@@ -55,19 +64,20 @@ jobs:
           curl -L -O https://github.com/libffi/libffi/archive/v3.4.2.tar.gz && \
           tar zxf v3.4.2.tar.gz && cd libffi-3.4.2 && \
           ./autogen.sh && \
-          ./configure --without-gcc-arch --disable-docs && \
+          ./configure --without-gcc-arch --disable-docs --with-pic --enable-shared=no && \
           make && \
           make install && \
-          ldconfig
-        # TODO: update default to '' once CIBW 2.1.3 ships: https://github.com/pypa/cibuildwheel/pull/829
-        CIBW_MANYLINUX_X86_64_IMAGE: ${{ matrix.manylinux_img || 'manylinux2010' }}
-        CIBW_MANYLINUX_I686_IMAGE: ${{ matrix.manylinux_img || 'manylinux2010' }}
+          ldconfig || true
+        CIBW_ENVIRONMENT_PASS_LINUX: CFLAGS  # ensure that the build container can see our overridden build config
+        CIBW_MANYLINUX_X86_64_IMAGE: ${{ matrix.manylinux_img || '' }}
+        CIBW_MANYLINUX_I686_IMAGE: ${{ matrix.manylinux_img || '' }}
+        CIBW_PRERELEASE_PYTHONS: 'True'
         CIBW_TEST_REQUIRES: pytest
-        CIBW_TEST_COMMAND: python -m pytest {project}/c {project}/testing
+        CIBW_TEST_COMMAND: PYTHONUNBUFFERED=1 python -m pytest {project}
       run: |
         python -m pip install --upgrade "${{ matrix.cibw_version || 'cibuildwheel' }}"
 
-        # actually build libyaml + wheel (using env tweaks above)
+        # actually build libffi + wheel (using env tweaks above)
         python -m cibuildwheel --output-dir dist .
 
 
@@ -94,6 +104,7 @@ jobs:
         - spec: cp38-macosx_x86_64
         - spec: cp39-macosx_x86_64
         - spec: cp310-macosx_x86_64
+        - spec: cp311-macosx_x86_64
         # build for arm64 under a hacked macOS 12 self-hosted x86_64-on-arm64 runner until arm64 is fully supported
         # FIXME: ? cp38-macosx_arm64 requires special handling and fails some test_zdist tests under cibw 2.1.2, skip it (so Apple's XCode python3 won't have a wheel)
         - spec: cp39-macosx_arm64
@@ -107,6 +118,14 @@ jobs:
           runs_on: [self-hosted, macOS]
           run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
           sdkroot: macosx11.3
+
+        - spec: cp311-macosx_arm64
+          deployment_target: '11.0'
+          runs_on: [self-hosted, macOS]
+          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+          sdkroot: macosx11.3
+
+
     steps:
     - name: clone repo
       uses: actions/checkout@v2
@@ -119,8 +138,9 @@ jobs:
     - name: build/test wheels
       env:
         CIBW_BUILD: ${{ matrix.spec }}
+        CIBW_PRERELEASE_PYTHONS: 'True'
         CIBW_TEST_REQUIRES: pytest
-        CIBW_TEST_COMMAND: pip install pip --upgrade; cd {project}; pytest
+        CIBW_TEST_COMMAND: pip install pip --upgrade; cd {project}; PYTHONUNBUFFERED=1 pytest
       run: |
         if [[ -n "${{ matrix.deployment_target || '' }}" ]]
         then
@@ -141,7 +161,7 @@ jobs:
         if-no-files-found: error
 
   windows:
-    runs-on: windows-2016
+    runs-on: windows-2019
     strategy:
       matrix:
         include:
@@ -152,6 +172,7 @@ jobs:
         - spec: cp38-win_amd64
         - spec: cp39-win_amd64
         - spec: cp310-win_amd64
+        - spec: cp311-win_amd64
         - spec: cp27-win32
           cibw_version: cibuildwheel==1.10  # last release with proper py2.7 Windows support
         - spec: cp36-win32
@@ -159,6 +180,7 @@ jobs:
         - spec: cp38-win32
         - spec: cp39-win32
         - spec: cp310-win32
+        - spec: cp311-win32
     steps:
     - name: clone repo
       uses: actions/checkout@v2
@@ -180,6 +202,7 @@ jobs:
     - name: build/test wheels
       env:
         CIBW_BUILD: ${{ matrix.spec }}
+        CIBW_PRERELEASE_PYTHONS: 'True'
       run: |
         python -m pip install --upgrade pip
         pip install "${{ matrix.cibw_version || 'cibuildwheel'}}"
diff --git a/c/_cffi_backend.c b/c/_cffi_backend.c
index ffecbf9..b9618bd 100644
--- a/c/_cffi_backend.c
+++ b/c/_cffi_backend.c
@@ -2,7 +2,7 @@
 #include <Python.h>
 #include "structmember.h"
 
-#define CFFI_VERSION  "1.15.0"
+#define CFFI_VERSION  "1.15.1"
 
 #ifdef MS_WIN32
 #include <windows.h>
@@ -2197,7 +2197,7 @@ static PyObject *_frombuf_repr(CDataObject *cd, const char *cd_type_name)
     }
 }
 
-static PyObject *cdataowning_repr(CDataObject *cd)
+static Py_ssize_t cdataowning_size_bytes(CDataObject *cd)
 {
     Py_ssize_t size = _cdata_var_byte_size(cd);
     if (size < 0) {
@@ -2208,6 +2208,12 @@ static PyObject *cdataowning_repr(CDataObject *cd)
         else
             size = cd->c_type->ct_size;
     }
+    return size;
+}
+
+static PyObject *cdataowning_repr(CDataObject *cd)
+{
+    Py_ssize_t size = cdataowning_size_bytes(cd);
     return PyText_FromFormat("<cdata '%s' owning %zd bytes>",
                              cd->c_type->ct_name, size);
 }
@@ -4603,7 +4609,7 @@ static PyObject *get_unique_type(CTypeDescrObject *x,
            array      [ctype, length]
            funcptr    [ctresult, ellipsis+abi, num_args, ctargs...]
     */
-    PyObject *key, *y;
+    PyObject *key, *y, *res;
     void *pkey;
 
     key = PyBytes_FromStringAndSize(NULL, keylength * sizeof(void *));
@@ -4635,8 +4641,9 @@ static PyObject *get_unique_type(CTypeDescrObject *x,
     /* the 'value' in unique_cache doesn't count as 1, but don't use
        Py_DECREF(x) here because it will confuse debug builds into thinking
        there was an extra DECREF in total. */
-    ((PyObject *)x)->ob_refcnt--;
-    return (PyObject *)x;
+    res = (PyObject *)x;
+    Py_SET_REFCNT(res, Py_REFCNT(res) - 1);
+    return res;
 
  error:
     Py_DECREF(x);
@@ -5665,7 +5672,8 @@ static ffi_type *fb_fill_type(struct funcbuilder_s *fb, CTypeDescrObject *ct,
     }
 }
 
-#define ALIGN_ARG(n)  ((n) + 7) & ~7
+#define ALIGN_TO(n, a)  ((n) + ((a)-1)) & ~((a)-1)
+#define ALIGN_ARG(n)    ALIGN_TO(n, 8)
 
 static int fb_build(struct funcbuilder_s *fb, PyObject *fargs,
                     CTypeDescrObject *fresult)
@@ -5690,10 +5698,12 @@ static int fb_build(struct funcbuilder_s *fb, PyObject *fargs,
         /* exchange data size */
         /* first, enough room for an array of 'nargs' pointers */
         exchange_offset = nargs * sizeof(void*);
+        /* then enough room for the result --- which means at least
+           sizeof(ffi_arg), according to the ffi docs, but we also
+           align according to the result type, for issue #531 */
+        exchange_offset = ALIGN_TO(exchange_offset, fb->rtype->alignment);
         exchange_offset = ALIGN_ARG(exchange_offset);
         cif_descr->exchange_offset_arg[0] = exchange_offset;
-        /* then enough room for the result --- which means at least
-           sizeof(ffi_arg), according to the ffi docs */
         i = fb->rtype->size;
         if (i < (Py_ssize_t)sizeof(ffi_arg))
             i = sizeof(ffi_arg);
@@ -5721,6 +5731,7 @@ static int fb_build(struct funcbuilder_s *fb, PyObject *fargs,
         if (fb->atypes != NULL) {
             fb->atypes[i] = atype;
             /* exchange data size */
+            exchange_offset = ALIGN_TO(exchange_offset, atype->alignment);
             exchange_offset = ALIGN_ARG(exchange_offset);
             cif_descr->exchange_offset_arg[1 + i] = exchange_offset;
             exchange_offset += atype->size;
@@ -5737,6 +5748,7 @@ static int fb_build(struct funcbuilder_s *fb, PyObject *fargs,
 }
 
 #undef ALIGN_ARG
+#undef ALIGN_TO
 
 static void fb_cat_name(struct funcbuilder_s *fb, const char *piece,
                         int piecelen)
@@ -7010,12 +7022,14 @@ b_buffer_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     /* this is the constructor of the type implemented in minibuffer.h */
     CDataObject *cd;
     Py_ssize_t size = -1;
+    int explicit_size;
     static char *keywords[] = {"cdata", "size", NULL};
 
     if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!|n:buffer", keywords,
                                      &CData_Type, &cd, &size))
         return NULL;
 
+    explicit_size = size >= 0;
     if (size < 0)
         size = _cdata_var_byte_size(cd);
 
@@ -7039,6 +7053,20 @@ b_buffer_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
                      cd->c_type->ct_name);
         return NULL;
     }
+
+    if (explicit_size && CDataOwn_Check(cd)) {
+        Py_ssize_t size_max = cdataowning_size_bytes(cd);
+        if (size > size_max) {
+            char msg[256];
+            sprintf(msg, "ffi.buffer(cdata, bytes): creating a buffer of %llu "
+                         "bytes over a cdata that owns only %llu bytes.  This "
+                         "will crash if you access the extra memory",
+                         (unsigned PY_LONG_LONG)size,
+                         (unsigned PY_LONG_LONG)size_max);
+            if (PyErr_WarnEx(PyExc_UserWarning, msg, 1))
+                return NULL;
+        }
+    }
     /*WRITE(cd->c_data, size)*/
     return minibuffer_new(cd->c_data, size, (PyObject *)cd);
 }
diff --git a/c/libffi_arm64/README b/c/libffi_arm64/README
index 3b8f133..f531e5f 100644
--- a/c/libffi_arm64/README
+++ b/c/libffi_arm64/README
@@ -1,5 +1,5 @@
-Libffi package for ARM64 is copied from cpython binary dependencies
+Please run build_libffi.bat to generate the libffi static library and header files
 
-https://github.com/python/cpython-bin-deps/archive/libffi.zip
+Environment variable LIBFFI_SOURCE needs to be set to libffi source before invoking the script.
 
-The library file has been renamed from libffi-7.lib to ffi.lib to avoid special casing
\ No newline at end of file
+Libffi source can be downloaded from https://github.com/libffi/libffi
\ No newline at end of file
diff --git a/c/libffi_arm64/build_libffi.bat b/c/libffi_arm64/build_libffi.bat
new file mode 100644
index 0000000..be4e23b
--- /dev/null
+++ b/c/libffi_arm64/build_libffi.bat
@@ -0,0 +1,71 @@
+@echo off

+goto :Run

+ 

+:Usage

+echo.

+echo Before running prepare_libffi.bat

+echo .

+echo   LIBFFI_SOURCE environment variable must be set to the location of libffi source

+echo   Source can be checked out from https://github.com/libffi/libffi

+echo.

+echo   Cygwin needs to be installed (Invoke with --install-cygwin to install)

+echo.  

+echo.  Visual Studio 2017 or newer with ARM64 toolchain needs to be installed

+:Run

+set INSTALL_CYGWIN=

+ 

+:CheckOpts

+if "%1"=="" goto :CheckOptsDone

+if /I "%1"=="-?" goto :Usage

+if /I "%1"=="--install-cygwin" (set INSTALL_CYGWIN=1) & shift & goto :CheckOpts

+goto :Usage

+ 

+:CheckOptsDone

+ 

+if "%INSTALL_CYGWIN%"=="1" call :InstallCygwin

+ 

+REM Set build variables

+ 

+set BUILD=i686-pc-cygwin

+set HOST=aarch64-w64-cygwin

+if NOT DEFINED SH if exist c:\cygwin\bin\sh.exe set SH=c:\cygwin\bin\sh.exe

+ 

+REM Initialise ARM64 build environment

+ 

+if NOT DEFINED VCVARSALL (

+  for /F "tokens=*" %%i in ('"%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe" -property installationPath -latest -prerelease -products * -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64') DO @(set VCVARSALL="%%i\VC\Auxiliary\Build\vcvarsall.bat")

+)

+if ^%VCVARSALL:~0,1% NEQ ^" SET VCVARSALL="%VCVARSALL%"

+call %VCVARSALL% x86_arm64

+pushd %LIBFFI_SOURCE%

+%SH% --login -lc "cygcheck -dc cygwin"

+set GET_MSVCC=%SH% -lc "cd $LIBFFI_SOURCE; export MSVCC=`/usr/bin/find $PWD -name msvcc.sh`; echo ${MSVCC};"

+FOR /F "usebackq delims==" %%i IN (`%GET_MSVCC%`) do @set MSVCC=%%i

+set MSVCC=%MSVCC% -marm64

+

+echo Configuring and building libffi for ARM64

+ 

+%SH% -lc "(cd $LIBFFI_SOURCE; ./autogen.sh)"

+%SH% -lc "(cd $LIBFFI_SOURCE; ./configure CC='%MSVCC%' CXX='%MSVCC%' LD='link' CPP='cl -nologo -EP' CXXCPP='cl -nologo -EP' CPPFLAGS='-DFFI_BUILDING_DLL'  NM='dumpbin -symbols' STRIP=':' --build=$BUILD --host=$HOST --enable-static --disable-shared)"

+%SH% -lc "(cd $LIBFFI_SOURCE; cp src/aarch64/ffitarget.h include)"

+%SH% -lc "(cd $LIBFFI_SOURCE; make)"

+

+set LIBFFI_OUT=%~dp0

+

+echo copying files to %LIBFFI_OUT%

+if not exist %LIBFFI_OUT%\include (md %LIBFFI_OUT%\include)

+copy %LIBFFI_SOURCE%\%HOST%\.libs\libffi.lib %LIBFFI_OUT%\ffi.lib || exit /B 1

+copy %LIBFFI_SOURCE%\%HOST%\fficonfig.h %LIBFFI_OUT%\include || exit /B 1

+copy %LIBFFI_SOURCE%\%HOST%\include\*.h %LIBFFI_OUT%\include || exit /B 1

+popd

+exit /B

+ 

+:InstallCygwin

+setlocal

+set CYG_ROOT=C:/cygwin

+set CYG_CACHE=C:/cygwin/var/cache/setup

+set CYG_MIRROR=http://mirrors.kernel.org/sourceware/cygwin/

+powershell -c "Invoke-WebRequest https://cygwin.com/setup-x86.exe -OutFile setup.exe"

+setup.exe -qgnNdO -R "%CYG_ROOT%" -s "%CYG_MIRROR%" -l "%CYG_CACHE%" -P dejagnu -P autoconf -P automake -P libtool -P make

+endlocal

+exit /B

diff --git a/c/libffi_arm64/ffi.lib b/c/libffi_arm64/ffi.lib
index 4a8b84b..b3f79e1 100644
--- a/c/libffi_arm64/ffi.lib
+++ b/c/libffi_arm64/ffi.lib
diff --git a/c/libffi_arm64/include/ffi.h b/c/libffi_arm64/include/ffi.h
index d91c3e1..87eb14b 100644
--- a/c/libffi_arm64/include/ffi.h
+++ b/c/libffi_arm64/include/ffi.h
@@ -1,6 +1,7 @@
 /* -----------------------------------------------------------------*-C-*-
-   libffi 3.3-rc0 - Copyright (c) 2011, 2014 Anthony Green
-                    - Copyright (c) 1996-2003, 2007, 2008 Red Hat, Inc.
+   libffi 3.4.2
+     - Copyright (c) 2011, 2014, 2019, 2021 Anthony Green
+     - Copyright (c) 1996-2003, 2007, 2008 Red Hat, Inc.
 
    Permission is hereby granted, free of charge, to any person
    obtaining a copy of this software and associated documentation
@@ -217,7 +218,8 @@ FFI_EXTERN ffi_type ffi_type_complex_longdouble;
 typedef enum {
   FFI_OK = 0,
   FFI_BAD_TYPEDEF,
-  FFI_BAD_ABI
+  FFI_BAD_ABI,
+  FFI_BAD_ARGTYPE
 } ffi_status;
 
 typedef struct {
@@ -269,7 +271,7 @@ typedef ffi_raw ffi_java_raw;
 #endif
 
 
-FFI_API 
+FFI_API
 void ffi_raw_call (ffi_cif *cif,
 		   void (*fn)(void),
 		   void *rvalue,
@@ -288,15 +290,15 @@ FFI_API
 void ffi_java_raw_call (ffi_cif *cif,
 			void (*fn)(void),
 			void *rvalue,
-			ffi_java_raw *avalue);
+			ffi_java_raw *avalue) __attribute__((deprecated));
 #endif
 
 FFI_API
-void ffi_java_ptrarray_to_raw (ffi_cif *cif, void **args, ffi_java_raw *raw);
+void ffi_java_ptrarray_to_raw (ffi_cif *cif, void **args, ffi_java_raw *raw) __attribute__((deprecated));
 FFI_API
-void ffi_java_raw_to_ptrarray (ffi_cif *cif, ffi_java_raw *raw, void **args);
+void ffi_java_raw_to_ptrarray (ffi_cif *cif, ffi_java_raw *raw, void **args) __attribute__((deprecated));
 FFI_API
-size_t ffi_java_raw_size (ffi_cif *cif);
+size_t ffi_java_raw_size (ffi_cif *cif) __attribute__((deprecated));
 
 /* ---- Definitions for closures ----------------------------------------- */
 
@@ -310,7 +312,10 @@ typedef struct {
   void *trampoline_table;
   void *trampoline_table_entry;
 #else
-  char tramp[FFI_TRAMPOLINE_SIZE];
+  union {
+    char tramp[FFI_TRAMPOLINE_SIZE];
+    void *ftramp;
+  };
 #endif
   ffi_cif   *cif;
   void     (*fun)(ffi_cif*,void*,void**,void*);
@@ -330,6 +335,14 @@ typedef struct {
 FFI_API void *ffi_closure_alloc (size_t size, void **code);
 FFI_API void ffi_closure_free (void *);
 
+#if defined(PA_LINUX) || defined(PA_HPUX)
+#define FFI_CLOSURE_PTR(X) ((void *)((unsigned int)(X) | 2))
+#define FFI_RESTORE_PTR(X) ((void *)((unsigned int)(X) & ~3))
+#else
+#define FFI_CLOSURE_PTR(X) (X)
+#define FFI_RESTORE_PTR(X) (X)
+#endif
+
 FFI_API ffi_status
 ffi_prep_closure (ffi_closure*,
 		  ffi_cif *,
@@ -363,8 +376,8 @@ typedef struct {
 
 #if !FFI_NATIVE_RAW_API
 
-  /* If this is enabled, then a raw closure has the same layout 
-     as a regular closure.  We use this to install an intermediate 
+  /* If this is enabled, then a raw closure has the same layout
+     as a regular closure.  We use this to install an intermediate
      handler to do the transaltion, void** -> ffi_raw*.  */
 
   void     (*translate_args)(ffi_cif*,void*,void**,void*);
@@ -389,8 +402,8 @@ typedef struct {
 
 #if !FFI_NATIVE_RAW_API
 
-  /* If this is enabled, then a raw closure has the same layout 
-     as a regular closure.  We use this to install an intermediate 
+  /* If this is enabled, then a raw closure has the same layout
+     as a regular closure.  We use this to install an intermediate
      handler to do the translation, void** -> ffi_raw*.  */
 
   void     (*translate_args)(ffi_cif*,void*,void**,void*);
@@ -421,14 +434,14 @@ FFI_API ffi_status
 ffi_prep_java_raw_closure (ffi_java_raw_closure*,
 		           ffi_cif *cif,
 		           void (*fun)(ffi_cif*,void*,ffi_java_raw*,void*),
-		           void *user_data);
+		           void *user_data) __attribute__((deprecated));
 
 FFI_API ffi_status
 ffi_prep_java_raw_closure_loc (ffi_java_raw_closure*,
 			       ffi_cif *cif,
 			       void (*fun)(ffi_cif*,void*,ffi_java_raw*,void*),
 			       void *user_data,
-			       void *codeloc);
+			       void *codeloc) __attribute__((deprecated));
 #endif
 
 #endif /* FFI_CLOSURES */
@@ -451,7 +464,7 @@ FFI_API void ffi_call_go (ffi_cif *cif, void (*fn)(void), void *rvalue,
 
 /* ---- Public interface definition -------------------------------------- */
 
-FFI_API 
+FFI_API
 ffi_status ffi_prep_cif(ffi_cif *cif,
 			ffi_abi abi,
 			unsigned int nargs,
@@ -484,18 +497,18 @@ ffi_status ffi_get_struct_offsets (ffi_abi abi, ffi_type *struct_type,
 #endif
 
 /* If these change, update src/mips/ffitarget.h. */
-#define FFI_TYPE_VOID       0    
+#define FFI_TYPE_VOID       0
 #define FFI_TYPE_INT        1
-#define FFI_TYPE_FLOAT      2    
+#define FFI_TYPE_FLOAT      2
 #define FFI_TYPE_DOUBLE     3
 #if 0
 #define FFI_TYPE_LONGDOUBLE 4
 #else
 #define FFI_TYPE_LONGDOUBLE FFI_TYPE_DOUBLE
 #endif
-#define FFI_TYPE_UINT8      5   
+#define FFI_TYPE_UINT8      5
 #define FFI_TYPE_SINT8      6
-#define FFI_TYPE_UINT16     7 
+#define FFI_TYPE_UINT16     7
 #define FFI_TYPE_SINT16     8
 #define FFI_TYPE_UINT32     9
 #define FFI_TYPE_SINT32     10
diff --git a/c/libffi_arm64/include/fficonfig.h b/c/libffi_arm64/include/fficonfig.h
index 5768c29..e888ff1 100644
--- a/c/libffi_arm64/include/fficonfig.h
+++ b/c/libffi_arm64/include/fficonfig.h
@@ -18,6 +18,9 @@
 /* Define this if you want extra debugging. */
 /* #undef FFI_DEBUG */
 
+/* Define this if you want statically defined trampolines */
+/* #undef FFI_EXEC_STATIC_TRAMP */
+
 /* Cannot use PROT_EXEC on this target, so, we revert to alternative means */
 /* #undef FFI_EXEC_TRAMPOLINE_TABLE */
 
@@ -77,12 +80,18 @@
 /* Define to 1 if you have the `memcpy' function. */
 /* #undef HAVE_MEMCPY */
 
+/* Define to 1 if you have the `memfd_create' function. */
+/* #undef HAVE_MEMFD_CREATE */
+
 /* Define to 1 if you have the <memory.h> header file. */
 #define HAVE_MEMORY_H 1
 
 /* Define to 1 if you have the `mkostemp' function. */
 /* #undef HAVE_MKOSTEMP */
 
+/* Define to 1 if you have the `mkstemp' function. */
+/* #undef HAVE_MKSTEMP */
+
 /* Define to 1 if you have the `mmap' function. */
 /* #undef HAVE_MMAP */
 
@@ -95,6 +104,9 @@
 /* Define if read-only mmap of a plain file works. */
 /* #undef HAVE_MMAP_FILE */
 
+/* Define if your compiler supports pointer authentication. */
+/* #undef HAVE_PTRAUTH */
+
 /* Define if .eh_frame sections should be read-only. */
 /* #undef HAVE_RO_EH_FRAME */
 
@@ -110,6 +122,9 @@
 /* Define to 1 if you have the <string.h> header file. */
 #define HAVE_STRING_H 1
 
+/* Define to 1 if you have the <sys/memfd.h> header file. */
+/* #undef HAVE_SYS_MEMFD_H */
+
 /* Define to 1 if you have the <sys/mman.h> header file. */
 /* #undef HAVE_SYS_MMAN_H */
 
@@ -138,7 +153,7 @@
 #define PACKAGE_NAME "libffi"
 
 /* Define to the full name and version of this package. */
-#define PACKAGE_STRING "libffi 3.3-rc0"
+#define PACKAGE_STRING "libffi 3.4.2"
 
 /* Define to the one symbol short name of this package. */
 #define PACKAGE_TARNAME "libffi"
@@ -147,7 +162,7 @@
 #define PACKAGE_URL ""
 
 /* Define to the version of this package. */
-#define PACKAGE_VERSION "3.3-rc0"
+#define PACKAGE_VERSION "3.4.2"
 
 /* The size of `double', as computed by sizeof. */
 #define SIZEOF_DOUBLE 8
@@ -177,7 +192,7 @@
 /* #undef USING_PURIFY */
 
 /* Version number of package */
-#define VERSION "3.3-rc0"
+#define VERSION "3.4.2"
 
 /* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
    significant byte first (like Motorola and SPARC, unlike Intel). */
diff --git a/c/libffi_arm64/include/ffitarget.h b/c/libffi_arm64/include/ffitarget.h
index ecb6d2d..d5622e1 100644
--- a/c/libffi_arm64/include/ffitarget.h
+++ b/c/libffi_arm64/include/ffitarget.h
@@ -32,7 +32,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #define FFI_SIZEOF_JAVA_RAW  4
 typedef unsigned long long ffi_arg;
 typedef signed long long ffi_sarg;
-#elif defined(_M_ARM64)
+#elif defined(_WIN32)
 #define FFI_SIZEOF_ARG 8
 typedef unsigned long long ffi_arg;
 typedef signed long long ffi_sarg;
@@ -45,8 +45,13 @@ typedef enum ffi_abi
   {
     FFI_FIRST_ABI = 0,
     FFI_SYSV,
+    FFI_WIN64,
     FFI_LAST_ABI,
+#if defined(_WIN32)
+    FFI_DEFAULT_ABI = FFI_WIN64
+#else
     FFI_DEFAULT_ABI = FFI_SYSV
+#endif
   } ffi_abi;
 #endif
 
@@ -69,22 +74,22 @@ typedef enum ffi_abi
 #define FFI_TRAMPOLINE_CLOSURE_OFFSET FFI_TRAMPOLINE_SIZE
 #endif
 
-#ifdef _M_ARM64
+#ifdef _WIN32
 #define FFI_EXTRA_CIF_FIELDS unsigned is_variadic
 #endif
+#define FFI_TARGET_SPECIFIC_VARIADIC
 
 /* ---- Internal ---- */
 
 #if defined (__APPLE__)
-#define FFI_TARGET_SPECIFIC_VARIADIC
 #define FFI_EXTRA_CIF_FIELDS unsigned aarch64_nfixedargs
-#elif !defined(_M_ARM64)
+#elif !defined(_WIN32)
 /* iOS and Windows reserve x18 for the system.  Disable Go closures until
    a new static chain is chosen.  */
 #define FFI_GO_CLOSURES 1
 #endif
 
-#ifndef _M_ARM64
+#ifndef _WIN32
 /* No complex type on Windows */
 #define FFI_TARGET_HAS_COMPLEX_TYPE
 #endif
diff --git a/c/test_c.py b/c/test_c.py
index 654584d..cde83b8 100644
--- a/c/test_c.py
+++ b/c/test_c.py
@@ -1,5 +1,15 @@
 import py
 import pytest
+import sys
+
+is_musl = False
+if sys.platform == 'linux':
+    try:
+        from packaging.tags import platform_tags
+        is_musl = any(t.startswith('musllinux') for t in platform_tags())
+        del platform_tags
+    except ImportError:
+        pass
 
 def _setup_path():
     import os, sys
@@ -17,7 +27,7 @@ from _cffi_backend import __version__
 # ____________________________________________________________
 
 import sys
-assert __version__ == "1.15.0", ("This test_c.py file is for testing a version"
+assert __version__ == "1.15.1", ("This test_c.py file is for testing a version"
                                  " of cffi that differs from the one that we"
                                  " get from 'import _cffi_backend'")
 if sys.version_info < (3,):
@@ -93,7 +103,8 @@ def test_all_rtld_symbols():
     if sys.platform.startswith("linux"):
         RTLD_NODELETE
         RTLD_NOLOAD
-        RTLD_DEEPBIND
+        if not is_musl:
+            RTLD_DEEPBIND
 
 def test_new_primitive_type():
     py.test.raises(KeyError, new_primitive_type, "foo")
@@ -1296,7 +1307,7 @@ def test_read_variable_as_unknown_length_array():
 def test_write_variable():
     ## FIXME: this test assumes glibc specific behavior, it's not compliant with C standard
     ## https://bugs.pypy.org/issue1643
-    if not sys.platform.startswith("linux"):
+    if not sys.platform.startswith("linux") or is_musl:
         py.test.skip("untested")
     BVoidP = new_pointer_type(new_void_type())
     ll = find_and_load_library('c')
@@ -1331,9 +1342,11 @@ def test_callback_exception():
     except ImportError:
         import io as cStringIO    # Python 3
     import linecache
-    def matches(istr, ipattern, ipattern38):
+    def matches(istr, ipattern, ipattern38, ipattern311):
         if sys.version_info >= (3, 8):
             ipattern = ipattern38
+        if sys.version_info >= (3, 11):
+            ipattern = ipattern311
         str, pattern = istr, ipattern
         while '$' in pattern:
             i = pattern.index('$')
@@ -1387,6 +1400,16 @@ Traceback (most recent call last):
   File "$", line $, in check_value
     $
 ValueError: 42
+""", """\
+Exception ignored from cffi callback <function$Zcb1 at 0x$>:
+Traceback (most recent call last):
+  File "$", line $, in Zcb1
+    $
+    $
+  File "$", line $, in check_value
+    $
+    $
+ValueError: 42
 """)
         sys.stderr = cStringIO.StringIO()
         bigvalue = 20000
@@ -1401,6 +1424,13 @@ Traceback (most recent call last):
   File "$", line $, in test_callback_exception
     $
 OverflowError: integer 60000 does not fit 'short'
+""", """\
+Exception ignored from cffi callback <function$Zcb1 at 0x$>, trying to convert the result back to C:
+Traceback (most recent call last):
+  File "$", line $, in test_callback_exception
+    $
+    $
+OverflowError: integer 60000 does not fit 'short'
 """)
         sys.stderr = cStringIO.StringIO()
         bigvalue = 20000
@@ -1449,6 +1479,19 @@ Traceback (most recent call last):
   File "$", line $, in test_callback_exception
     $
 TypeError: $integer$
+""", """\
+Exception ignored from cffi callback <function$Zcb1 at 0x$>, trying to convert the result back to C:
+Traceback (most recent call last):
+  File "$", line $, in test_callback_exception
+    $
+    $
+OverflowError: integer 60000 does not fit 'short'
+Exception ignored during handling of the above exception by 'onerror':
+Traceback (most recent call last):
+  File "$", line $, in test_callback_exception
+    $
+    $
+TypeError: $integer$
 """)
         #
         sys.stderr = cStringIO.StringIO()
@@ -1478,6 +1521,19 @@ Traceback (most recent call last):
   File "$", line $, in oops
     $
 AttributeError: 'str' object has no attribute 'append$
+""", """\
+Exception ignored from cffi callback <function$Zcb1 at 0x$>, trying to convert the result back to C:
+Traceback (most recent call last):
+  File "$", line $, in test_callback_exception
+    $
+    $
+OverflowError: integer 60000 does not fit 'short'
+Exception ignored during handling of the above exception by 'onerror':
+Traceback (most recent call last):
+  File "$", line $, in oops
+    $
+    $
+AttributeError: 'str' object has no attribute 'append$
 """)
     finally:
         sys.stderr = orig_stderr
@@ -3453,6 +3509,18 @@ def test_bitfield_as_ppc_gcc():
     _test_bitfield_details(flag=SF_GCC_X86_BITFIELDS|SF_GCC_BIG_ENDIAN)
 
 
+def buffer_warning(cdata):
+    import warnings
+    buf = buffer(cdata)
+    bytes = len(buf)
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        buffer(cdata, bytes)
+        assert len(w) == 0
+        buffer(cdata, bytes + 1)
+        assert len(w) <= 1
+        return len(w) == 1
+
 def test_struct_array_no_length():
     BInt = new_primitive_type("int")
     BIntP = new_pointer_type(BInt)
@@ -3567,6 +3635,7 @@ def test_struct_array_no_length():
     assert p.a[1] == 20
     assert p.a[2] == 30
     assert p.a[3] == 0
+    assert buffer_warning(p)
     #
     # struct of struct of varsized array
     BStruct2 = new_struct_type("bar")
@@ -3575,6 +3644,20 @@ def test_struct_array_no_length():
     for i in range(2):   # try to detect heap overwrites
         p = newp(new_pointer_type(BStruct2), [100, [200, list(range(50))]])
         assert p.tail.y[49] == 49
+    assert buffer_warning(p)
+    assert not buffer_warning(cast(new_pointer_type(BStruct2), p))
+    assert not buffer_warning(cast(BIntP, p))
+
+def test_more_buffer_warning():
+    BChar = new_primitive_type("unsigned char")
+    BCharP = new_pointer_type(BChar)
+    BArray = new_array_type(BCharP, 10)   # char[10]
+    p = newp(BArray)
+    assert buffer_warning(p)
+    assert not buffer_warning(cast(BCharP, p))
+    p = newp(BCharP)
+    assert buffer_warning(p)
+    assert not buffer_warning(cast(BCharP, p))
 
 
 def test_struct_array_no_length_explicit_position():
diff --git a/cffi/__init__.py b/cffi/__init__.py
index 82a9618..90e2e65 100644
--- a/cffi/__init__.py
+++ b/cffi/__init__.py
@@ -5,8 +5,8 @@ from .api import FFI
 from .error import CDefError, FFIError, VerificationError, VerificationMissing
 from .error import PkgConfigError
 
-__version__ = "1.15.0"
-__version_info__ = (1, 15, 0)
+__version__ = "1.15.1"
+__version_info__ = (1, 15, 1)
 
 # The verifier module file names are based on the CRC32 of a string that
 # contains the following version number.  It may be older than __version__
diff --git a/cffi/_embedding.h b/cffi/_embedding.h
index e863d85..8e8df88 100644
--- a/cffi/_embedding.h
+++ b/cffi/_embedding.h
@@ -22,7 +22,8 @@ extern "C" {
 
    * _cffi_call_python_org, which on CPython is actually part of the
      _cffi_exports[] array, is the function pointer copied from
-     _cffi_backend.
+     _cffi_backend.  If _cffi_start_python() fails, then this is set
+     to NULL; otherwise, it should never be NULL.
 
    After initialization is complete, both are equal.  However, the
    first one remains equal to &_cffi_start_and_call_python until the
@@ -224,7 +225,7 @@ static int _cffi_initialize_python(void)
 
         if (f != NULL && f != Py_None) {
             PyFile_WriteString("\nFrom: " _CFFI_MODULE_NAME
-                               "\ncompiled with cffi version: 1.15.0"
+                               "\ncompiled with cffi version: 1.15.1"
                                "\n_cffi_backend module: ", f);
             modules = PyImport_GetModuleDict();
             mod = PyDict_GetItemString(modules, "_cffi_backend");
diff --git a/cffi/recompiler.py b/cffi/recompiler.py
index 86b37d7..5d9d32d 100644
--- a/cffi/recompiler.py
+++ b/cffi/recompiler.py
@@ -407,7 +407,7 @@ class Recompiler:
             prnt('  NULL,  /* no includes */')
         prnt('  %d,  /* num_types */' % (len(self.cffi_types),))
         flags = 0
-        if self._num_externpy:
+        if self._num_externpy > 0 or self.ffi._embedding is not None:
             flags |= 1     # set to mean that we use extern "Python"
         prnt('  %d,  /* flags */' % flags)
         prnt('};')
@@ -422,7 +422,7 @@ class Recompiler:
         prnt('PyMODINIT_FUNC')
         prnt('_cffi_pypyinit_%s(const void *p[])' % (base_module_name,))
         prnt('{')
-        if self._num_externpy:
+        if flags & 1:
             prnt('    if (((intptr_t)p[0]) >= 0x0A03) {')
             prnt('        _cffi_call_python_org = '
                  '(void(*)(struct _cffi_externpy_s *, char *))p[1];')
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 33e8c11..fb6421e 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -47,7 +47,7 @@ copyright = u'2012-2018, Armin Rigo, Maciej Fijalkowski'
 # The short X.Y version.
 version = '1.15'
 # The full version, including alpha/beta/rc tags.
-release = '1.15.0'
+release = '1.15.1'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/doc/source/installation.rst b/doc/source/installation.rst
index 6d55eb5..4859c83 100644
--- a/doc/source/installation.rst
+++ b/doc/source/installation.rst
@@ -52,13 +52,13 @@ Download and Installation:
 
 * https://pypi.python.org/pypi/cffi
 
-* Checksums of the "source" package version 1.15.0:
+* Checksums of the "source" package version 1.15.1:
 
-   - MD5: f3a3f26cd3335fc597479c9475da0a0b
+   - MD5: ...
 
-   - SHA1: 9c51c29e35510adf7f94542e1f8e05611930b07b
+   - SHA1: ...
 
-   - SHA256: 920f0d66a896c2d99f0adbb391f990a84091179542c205fa53ce5787aff87954
+   - SHA256: ...
 
 * Or grab the most current version from the `Heptapod page`_:
   ``hg clone https://foss.heptapod.net/pypy/cffi``
diff --git a/doc/source/overview.rst b/doc/source/overview.rst
index dbc3540..3de8a3f 100644
--- a/doc/source/overview.rst
+++ b/doc/source/overview.rst
@@ -15,7 +15,12 @@ two sections delve deeper in the CFFI library.
 
 Make sure you have `cffi installed`__.
 
+You can find these and some other complete demos in the demo__ directory
+of the repository__.
+
 .. __: installation.html
+.. __: https://foss.heptapod.net/pypy/cffi/-/tree/branch/default/demo
+.. __: https://foss.heptapod.net/pypy/cffi
 
 .. _out-of-line-api-level:
 .. _real-example:
diff --git a/doc/source/ref.rst b/doc/source/ref.rst
index 05c0f7c..946e48c 100644
--- a/doc/source/ref.rst
+++ b/doc/source/ref.rst
@@ -846,20 +846,35 @@ allowed.
    argument is identical to a ``item[]`` argument (and ``ffi.cdef()``
    doesn't record the difference).  So when you call such a function,
    you can pass an argument that is accepted by either C type, like
-   for example passing a Python string to a ``char *`` argument
+   for example passing a Python byte string to a ``char *`` argument
    (because it works for ``char[]`` arguments) or a list of integers
    to a ``int *`` argument (it works for ``int[]`` arguments).  Note
    that even if you want to pass a single ``item``, you need to
    specify it in a list of length 1; for example, a ``struct point_s
    *`` argument might be passed as ``[[x, y]]`` or ``[{'x': 5, 'y':
-   10}]``.
+   10}]``.  In all these cases (including passing a byte string to
+   a ``char *`` argument), the required C data structure is created
+   just before the call is done, and freed afterwards.
 
    As an optimization, CFFI assumes that a
-   function with a ``char *`` argument to which you pass a Python
+   function with a ``char *`` argument to which you pass a Python byte
    string will not actually modify the array of characters passed in,
-   and so passes directly a pointer inside the Python string object.
+   and so it attempts to pass directly a pointer inside the Python
+   byte string object.  This still doesn't mean that the ``char *``
+   argument can be stored by the C function and inspected later.
+   The ``char *`` is only valid for the duration of the call, even if
+   the Python object is kept alive for longer.
    (On PyPy, this optimization is only available since PyPy 5.4
-   with CFFI 1.8.)
+   with CFFI 1.8.  It may fail in rare cases and fall back to making
+   a copy anyway, but only for short strings so it shouldn't be
+   noticeable.)
+
+   If you need to pass a ``char *`` that must be valid for longer than
+   just the call, you need to build it explicitly, either with ``p =
+   ffi.new("char[]", mystring)`` (which makes a copy) or by not using a
+   byte string in the first place but something else like a buffer object,
+   or a bytearray and ``ffi.from_buffer()``; or just use
+   ``ffi.new("char[]", length)`` directly if possible.
 
 `[2]` C function calls are done with the GIL released.
 
diff --git a/doc/source/using.rst b/doc/source/using.rst
index 38c96ba..ccaa4db 100644
--- a/doc/source/using.rst
+++ b/doc/source/using.rst
@@ -383,6 +383,18 @@ argument and may mutate it!):
 
     assert lib.strlen("hello") == 5
 
+(Note that there is no guarantee that the ``char *`` passed to the
+function remains valid after the call is done.  Similarly, if you write
+``lib.f(x); lib.f(x)`` where ``x`` is a variable containing a byte string,
+the two calls to ``f()`` could sometimes receive different ``char *``
+pointers, with each of them only valid during the corresponding call.  This is
+important notably for PyPy which uses many optimizations tweaking the data
+underlying a byte string object.  CFFI will not make and free a copy of
+the whole string at *every* call---it usually won't---but you *cannot*
+write code that relies on it: there are cases were that would break.
+If you need a pointer to remain valid, you need to make one explicitly,
+for example with ``ptr = ffi.new("char[]", x)``.)
+
 You can also pass unicode strings as ``wchar_t *`` or ``char16_t *`` or
 ``char32_t *`` arguments.  Note that
 the C language makes no difference between argument declarations that
diff --git a/doc/source/whatsnew.rst b/doc/source/whatsnew.rst
index aa7f2fe..ff2b7ba 100644
--- a/doc/source/whatsnew.rst
+++ b/doc/source/whatsnew.rst
@@ -2,6 +2,15 @@
 What's New
 ======================
 
+v1.15.1
+=======
+
+* If you call `ffi.embedding_api()` but don't write any `extern "Python"`
+  function there, then the resulting C code would fail an assert.  Fixed.
+
+* Updated Windows/arm64 embedded libffi static lib to v3.4.2, and scripted
+  to ease future updates (thanks Niyas Sait!)
+
 v1.15.0
 =======
 
diff --git a/setup.py b/setup.py
index 5fd1a1c..4ce0007 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ sources = ['c/_cffi_backend.c']
 libraries = ['ffi']
 include_dirs = ['/usr/include/ffi',
                 '/usr/include/libffi']    # may be changed by pkg-config
-define_macros = []
+define_macros = [('FFI_BUILDING', '1')]   # for linking with libffi static library
 library_dirs = []
 extra_compile_args = []
 extra_link_args = []
@@ -156,6 +156,11 @@ if 'freebsd' in sys.platform:
     include_dirs.append('/usr/local/include')
     library_dirs.append('/usr/local/lib')
 
+forced_extra_objs = os.environ.get('CFFI_FORCE_STATIC', [])
+if forced_extra_objs:
+    forced_extra_objs = forced_extra_objs.split(';')
+
+
 if __name__ == '__main__':
     from setuptools import setup, Distribution, Extension
 
@@ -186,7 +191,7 @@ Contact
 
 `Mailing list <https://groups.google.com/forum/#!forum/python-cffi>`_
 """,
-        version='1.15.0',
+        version='1.15.1',
         packages=['cffi'] if cpython else [],
         package_data={'cffi': ['_cffi_include.h', 'parse_c_type.h', 
                                '_embedding.h', '_cffi_errors.h']}
@@ -209,6 +214,7 @@ Contact
             library_dirs=library_dirs,
             extra_compile_args=extra_compile_args,
             extra_link_args=extra_link_args,
+            extra_objects=forced_extra_objs,
         )] if cpython else [],
 
         install_requires=[
diff --git a/testing/cffi0/test_function.py b/testing/cffi0/test_function.py
index b4bb23d..84d8db6 100644
--- a/testing/cffi0/test_function.py
+++ b/testing/cffi0/test_function.py
@@ -5,7 +5,7 @@ import math, os, sys
 import ctypes.util
 from cffi.backend_ctypes import CTypesBackend
 from testing.udir import udir
-from testing.support import FdWriteCapture, StdErrCapture
+from testing.support import FdWriteCapture, StdErrCapture, is_musl
 from .backend_tests import needs_dlopen_none
 
 try:
@@ -13,6 +13,12 @@ try:
 except ImportError:
     from io import StringIO
 
+try:
+    from packaging.tags import platform_tags
+    _platform_tags_cached = set(platform_tags())
+    _is_musl = any(t.startswith('musllinux') for t in _platform_tags_cached)
+except ImportError:
+    _is_musl = False
 
 lib_m = 'm'
 if sys.platform == 'win32':
@@ -20,6 +26,8 @@ if sys.platform == 'win32':
     import distutils.ccompiler
     if distutils.ccompiler.get_default_compiler() == 'msvc':
         lib_m = 'msvcrt'
+elif is_musl:
+    lib_m = 'c'
 
 class TestFunction(object):
     Backend = CTypesBackend
@@ -165,11 +173,15 @@ class TestFunction(object):
                           ffi.cast("long long", 168))
             ffi.C.fprintf(ffi.C.stderr, b"hello %p\n", ffi.NULL)
         res = fd.getvalue()
+        if is_musl:
+            nil_repr = b'0'
+        else:
+            nil_repr = b'(nil)'
         assert res == (b"hello with no arguments\n"
                        b"hello, world!\n"
                        b"hello, world2!\n"
                        b"hello int 42 long 84 long long 168\n"
-                       b"hello (nil)\n")
+                       b"hello " + nil_repr + b"\n")
 
     def test_must_specify_type_of_vararg(self):
         ffi = FFI(backend=self.Backend())
@@ -265,7 +277,7 @@ class TestFunction(object):
         assert res == 5
 
     def test_write_variable(self):
-        if not sys.platform.startswith('linux'):
+        if not sys.platform.startswith('linux') or _is_musl:
             py.test.skip("probably no symbol 'stdout' in the lib")
         ffi = FFI(backend=self.Backend())
         ffi.cdef("""
diff --git a/testing/cffi0/test_ownlib.py b/testing/cffi0/test_ownlib.py
index ffad879..bbdab8c 100644
--- a/testing/cffi0/test_ownlib.py
+++ b/testing/cffi0/test_ownlib.py
@@ -2,7 +2,7 @@ import py, sys, os
 import subprocess, weakref
 from cffi import FFI
 from cffi.backend_ctypes import CTypesBackend
-from testing.support import u
+from testing.support import u, is_musl
 
 
 SOURCE = """\
@@ -388,7 +388,7 @@ class TestOwnLib(object):
     def test_dlopen_handle(self):
         if self.module is None:
             py.test.skip("fix the auto-generation of the tiny test lib")
-        if sys.platform == 'win32':
+        if sys.platform == 'win32' or is_musl:
             py.test.skip("uses 'dl' explicitly")
         if self.__class__.Backend is CTypesBackend:
             py.test.skip("not for the ctypes backend")
diff --git a/testing/cffi0/test_parsing.py b/testing/cffi0/test_parsing.py
index a5e4587..5d93a8d 100644
--- a/testing/cffi0/test_parsing.py
+++ b/testing/cffi0/test_parsing.py
@@ -1,6 +1,7 @@
 import py, sys, re
 from cffi import FFI, FFIError, CDefError, VerificationError
 from .backend_tests import needs_dlopen_none
+from testing.support import is_musl
 
 
 class FakeBackend(object):
@@ -80,6 +81,9 @@ if sys.platform == 'win32':
     import distutils.ccompiler
     if distutils.ccompiler.get_default_compiler() == 'msvc':
         lib_m = 'msvcrt'
+elif is_musl:
+    lib_m = 'c'
+
 
 def test_simple():
     ffi = FFI(backend=FakeBackend())
diff --git a/testing/cffi0/test_unicode_literals.py b/testing/cffi0/test_unicode_literals.py
index 7b0a5cc..8838de5 100644
--- a/testing/cffi0/test_unicode_literals.py
+++ b/testing/cffi0/test_unicode_literals.py
@@ -9,6 +9,8 @@ from __future__ import unicode_literals
 #
 import sys, math
 from cffi import FFI
+from testing.support import is_musl
+
 
 lib_m = "m"
 if sys.platform == 'win32':
@@ -16,6 +18,8 @@ if sys.platform == 'win32':
     import distutils.ccompiler
     if distutils.ccompiler.get_default_compiler() == 'msvc':
         lib_m = 'msvcrt'
+elif is_musl:
+    lib_m = 'c'
 
 
 def test_cast():
diff --git a/testing/cffi0/test_verify.py b/testing/cffi0/test_verify.py
index 3a1c0b9..de1608d 100644
--- a/testing/cffi0/test_verify.py
+++ b/testing/cffi0/test_verify.py
@@ -3,7 +3,7 @@ import pytest
 import sys, os, math, weakref
 from cffi import FFI, VerificationError, VerificationMissing, model, FFIError
 from testing.support import *
-from testing.support import extra_compile_args
+from testing.support import extra_compile_args, is_musl
 
 
 lib_m = ['m']
@@ -1609,7 +1609,7 @@ def test_keepalive_ffi():
     assert func() == 42
 
 def test_FILE_stored_in_stdout():
-    if not sys.platform.startswith('linux'):
+    if not sys.platform.startswith('linux') or is_musl:
         py.test.skip("likely, we cannot assign to stdout")
     ffi = FFI()
     ffi.cdef("int printf(const char *, ...); FILE *setstdout(FILE *);")
diff --git a/testing/cffi1/test_cffi_binary.py b/testing/cffi1/test_cffi_binary.py
index 7cfbace..45421ed 100644
--- a/testing/cffi1/test_cffi_binary.py
+++ b/testing/cffi1/test_cffi_binary.py
@@ -1,10 +1,11 @@
 import py, sys, os
 import _cffi_backend
+from testing.support import is_musl
 
 def test_no_unknown_exported_symbols():
     if not hasattr(_cffi_backend, '__file__'):
         py.test.skip("_cffi_backend module is built-in")
-    if not sys.platform.startswith('linux'):
+    if not sys.platform.startswith('linux') or is_musl:
         py.test.skip("linux-only")
     g = os.popen("objdump -T '%s'" % _cffi_backend.__file__, 'r')
     for line in g:
@@ -17,6 +18,9 @@ def test_no_unknown_exported_symbols():
         name = line.split()[-1]
         if name.startswith('_') or name.startswith('.'):
             continue
-        if name not in ('init_cffi_backend', 'PyInit__cffi_backend'):
+        # a statically-linked libffi will always appear here without header hackage, ignore it if it's internal
+        if name.startswith('ffi_') and 'Base' in line:
+            continue
+        if name not in ('init_cffi_backend', 'PyInit__cffi_backend', 'cffistatic_ffi_call'):
             raise Exception("Unexpected exported name %r" % (name,))
     g.close()
diff --git a/testing/cffi1/test_re_python.py b/testing/cffi1/test_re_python.py
index 2ae0dd1..45dd70c 100644
--- a/testing/cffi1/test_re_python.py
+++ b/testing/cffi1/test_re_python.py
@@ -3,7 +3,7 @@ import py
 from cffi import FFI
 from cffi import recompiler, ffiplatform, VerificationMissing
 from testing.udir import udir
-from testing.support import u
+from testing.support import u, is_musl
 
 
 def setup_module(mod):
@@ -269,7 +269,7 @@ def test_selfref():
 def test_dlopen_handle():
     import _cffi_backend
     from re_python_pysrc import ffi
-    if sys.platform == 'win32':
+    if sys.platform == 'win32' or is_musl:
         py.test.skip("uses 'dl' explicitly")
     ffi1 = FFI()
     ffi1.cdef("""void *dlopen(const char *filename, int flags);
diff --git a/testing/cffi1/test_verify1.py b/testing/cffi1/test_verify1.py
index 33244cc..45df2b3 100644
--- a/testing/cffi1/test_verify1.py
+++ b/testing/cffi1/test_verify1.py
@@ -4,7 +4,7 @@ from cffi import FFI, FFIError, VerificationError, VerificationMissing, model
 from cffi import CDefError
 from cffi import recompiler
 from testing.support import *
-from testing.support import _verify, extra_compile_args
+from testing.support import _verify, extra_compile_args, is_musl
 import _cffi_backend
 
 lib_m = ['m']
@@ -1571,7 +1571,7 @@ def test_keepalive_ffi():
     assert func() == 42
 
 def test_FILE_stored_in_stdout():
-    if not sys.platform.startswith('linux'):
+    if not sys.platform.startswith('linux') or is_musl:
         py.test.skip("likely, we cannot assign to stdout")
     ffi = FFI()
     ffi.cdef("int printf(const char *, ...); FILE *setstdout(FILE *);")
diff --git a/testing/embedding/empty-test.c b/testing/embedding/empty-test.c
new file mode 100644
index 0000000..b00dd50
--- /dev/null
+++ b/testing/embedding/empty-test.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+void initialize_my_empty_cffi(void);
+
+int main(void)
+{
+    initialize_my_empty_cffi();
+    printf("OK\n");
+    return 0;
+}
+
diff --git a/testing/embedding/empty.py b/testing/embedding/empty.py
index aa8d830..1093505 100644
--- a/testing/embedding/empty.py
+++ b/testing/embedding/empty.py
@@ -4,7 +4,14 @@ ffi = cffi.FFI()
 
 ffi.embedding_api("")
 
-ffi.set_source("_empty_cffi", "")
+ffi.set_source("_empty_cffi", """
+void initialize_my_empty_cffi(void) {
+    if (cffi_start_python() != 0) {
+        printf("oops, cffi_start_python() returned non-0\\n");
+        abort();
+    }
+}
+""")
 
 fn = ffi.compile(verbose=True)
 print('FILENAME: %s' % (fn,))
diff --git a/testing/embedding/test_basic.py b/testing/embedding/test_basic.py
index 8d2e776..b29afd2 100644
--- a/testing/embedding/test_basic.py
+++ b/testing/embedding/test_basic.py
@@ -180,6 +180,9 @@ if sys.platform == 'win32':
 class TestBasic(EmbeddingTests):
     def test_empty(self):
         empty_cffi = self.prepare_module('empty')
+        self.compile('empty-test', [empty_cffi])
+        output = self.execute('empty-test')
+        assert output == 'OK\n'
 
     def test_basic(self):
         add1_cffi = self.prepare_module('add1')
diff --git a/testing/support.py b/testing/support.py
index 6339a94..a65375e 100644
--- a/testing/support.py
+++ b/testing/support.py
@@ -117,3 +117,12 @@ else:
         extra_compile_args = ['-Werror', '-Wall', '-Wextra', '-Wconversion',
                               '-Wno-unused-parameter',
                               '-Wno-unreachable-code']
+
+is_musl = False
+if sys.platform == 'linux':
+    try:
+        from packaging.tags import platform_tags
+        is_musl = any(t.startswith('musllinux') for t in platform_tags())
+        del platform_tags
+    except ImportError:
+        pass