Merge pull request #856 from centricular/static_library_pic

Add cross-platform PIC support for static libraries

mesonbuild/backend/backends.py

@@ -341,6 +341,8 @@ class Backend():
             commands += compiler.get_werror_args()
         if isinstance(target, build.SharedLibrary):
             commands += compiler.get_pic_args()
+        if isinstance(target, build.StaticLibrary) and target.pic:
+            commands += compiler.get_pic_args()
         for dep in target.get_external_deps():
             # Cflags required by external deps might have UNIX-specific flags,
             # so filter them out if needed

mesonbuild/build.py

@@ -44,12 +44,19 @@ known_basic_kwargs = {'install' : True,
                       'native' : True,
                      }
 
-known_shlib_kwargs = known_basic_kwargs.copy()
-known_shlib_kwargs.update({'version' : True,
-                           'soversion' : True,
-                           'name_prefix' : True,
-                           'name_suffix' : True,
-                           'vs_module_defs' : True})
+# These contain kwargs supported by both static and shared libraries. These are
+# combined here because a library() call might be shared_library() or
+# static_library() at runtime based on the configuration.
+# FIXME: Find a way to pass that info down here so we can have proper target
+# kwargs checking when specifically using shared_library() or static_library().
+known_lib_kwargs = known_basic_kwargs.copy()
+known_lib_kwargs.update({'version' : True, # Only for shared libs
+                         'soversion' : True, # Only for shared libs
+                         'name_prefix' : True,
+                         'name_suffix' : True,
+                         'vs_module_defs' : True, # Only for shared libs
+                         'pic' : True, # Only for static libs
+                        })
 
 def compilers_are_msvc(compilers):
     """
@@ -516,6 +523,16 @@ class BuildTarget():
                 if not isinstance(name_suffix, str):
                     raise InvalidArguments('Name suffix must be a string.')
                 self.suffix = name_suffix
+        if isinstance(self, StaticLibrary):
+            # You can't disable PIC on OS X. The compiler ignores -fno-PIC.
+            # PIC is always on for Windows (all code is position-independent
+            # since library loading is done differently)
+            if for_darwin(self.is_cross, self.environment) or for_windows(self.is_cross, self.environment):
+                self.pic = True
+            else:
+                self.pic = kwargs.get('pic', False)
+                if not isinstance(self.pic, bool):
+                    raise InvalidArguments('Argument pic must be boolean')
 
     def get_subdir(self):
         return self.subdir
@@ -618,6 +635,8 @@ by calling get_variable() on the subproject object.''')
                 t = t.held_object
             if not isinstance(t, (StaticLibrary, SharedLibrary)):
                 raise InvalidArguments('Link target is not library.')
+            if isinstance(self, SharedLibrary) and isinstance(t, StaticLibrary) and not t.pic:
+                raise InvalidArguments("Can't link a non-PIC static library into a shared library")
             if self.is_cross != t.is_cross:
                 raise InvalidArguments('Tried to mix cross built and native libraries in target %s.' % self.name)
             self.link_targets.append(t)
@@ -831,6 +850,9 @@ class StaticLibrary(BuildTarget):
     def type_suffix(self):
         return "@sta"
 
+    def check_unknown_kwargs(self, kwargs):
+        self.check_unknown_kwargs_int(kwargs, known_lib_kwargs)
+
 class SharedLibrary(BuildTarget):
     def __init__(self, name, subdir, subproject, is_cross, sources, objects, environment, kwargs):
         self.soversion = None
@@ -988,7 +1010,7 @@ class SharedLibrary(BuildTarget):
             self.link_depends.append(path)
 
     def check_unknown_kwargs(self, kwargs):
-        self.check_unknown_kwargs_int(kwargs, known_shlib_kwargs)
+        self.check_unknown_kwargs_int(kwargs, known_lib_kwargs)
 
     def get_import_filename(self):
         """

mesonbuild/compilers.py

@@ -1934,8 +1934,8 @@ class GnuCompiler:
             return defines[define]
 
     def get_pic_args(self):
-        if self.gcc_type == GCC_MINGW:
-            return [] # On Window gcc defaults to fpic being always on.
+        if self.gcc_type in (GCC_MINGW, GCC_OSX):
+            return [] # On Window and OS X, pic is always on.
         return ['-fPIC']
 
     def get_buildtype_args(self, buildtype):
@@ -2059,6 +2059,11 @@ class ClangCompiler():
             self.base_options.append('b_lundef')
             self.base_options.append('b_asneeded')
 
+    def get_pic_args(self):
+        if self.clang_type in (CLANG_WIN, CLANG_OSX):
+            return [] # On Window and OS X, pic is always on.
+        return ['-fPIC']
+
     def get_buildtype_args(self, buildtype):
         return gnulike_buildtype_args[buildtype]
 
@@ -2174,8 +2179,8 @@ class FortranCompiler(Compiler):
         return ' '.join(self.exelist)
 
     def get_pic_args(self):
-        if self.gcc_type == GCC_MINGW:
-            return [] # On Windows gcc defaults to fpic being always on.
+        if self.gcc_type in (GCC_MINGW, GCC_OSX):
+            return [] # On Window and OS X, pic is always on.
         return ['-fPIC']
 
     def get_std_shared_lib_link_args(self):

test cases/common/62 exe static shared/meson.build

@@ -1,6 +1,7 @@
 project('statchain', 'c')
 
 subdir('subdir')
-statlib = static_library('stat', 'stat.c', link_with : shlib)
-exe = executable('prog', 'prog.c', link_with : statlib)
+statlib = static_library('stat', 'stat.c', link_with : shlib, pic : true)
+shlib2 = shared_library('shr2', 'shlib2.c', link_with : statlib)
+exe = executable('prog', 'prog.c', link_with : shlib2)
 test('runtest', exe)

test cases/common/62 exe static shared/prog.c

@@ -1,5 +1,10 @@
+int shlibfunc2();
 int statlibfunc();
 
 int main(int argc, char **argv) {
-    return statlibfunc() == 42 ? 0 : 1;
+    if (statlibfunc() != 42)
+        return 1;
+    if (shlibfunc2() != 24)
+        return 1;
+    return 0;
 }

test cases/common/62 exe static shared/shlib2.c

@@ -0,0 +1,7 @@
+#include "subdir/exports.h"
+
+int statlibfunc(void);
+
+int DLL_PUBLIC shlibfunc2(void) {
+    return statlibfunc() - 18;
+}

test cases/common/62 exe static shared/subdir/exports.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#if defined _WIN32 || defined __CYGWIN__
+  #define DLL_PUBLIC __declspec(dllexport)
+#else
+  #if defined __GNUC__
+    #define DLL_PUBLIC __attribute__ ((visibility("default")))
+  #else
+    #pragma message ("Compiler does not support symbol visibility.")
+    #define DLL_PUBLIC
+  #endif
+#endif

test cases/common/62 exe static shared/subdir/shlib.c

@@ -1,13 +1,4 @@
-#if defined _WIN32 || defined __CYGWIN__
-  #define DLL_PUBLIC __declspec(dllexport)
-#else
-  #if defined __GNUC__
-    #define DLL_PUBLIC __attribute__ ((visibility("default")))
-  #else
-    #pragma message ("Compiler does not support symbol visibility.")
-    #define DLL_PUBLIC
-  #endif
-#endif
+#include "exports.h"
 
 int DLL_PUBLIC shlibfunc() {
     return 42;

test cases/failing/33 exe static shared/meson.build

@@ -0,0 +1,11 @@
+project('statchain', 'c')
+
+host_system = host_machine.system()
+if host_system == 'windows' or host_system == 'darwin'
+  error('Test only fails on Linux and BSD')
+endif
+
+statlib = static_library('stat', 'stat.c', pic : false)
+shlib2 = shared_library('shr2', 'shlib2.c', link_with : statlib)
+exe = executable('prog', 'prog.c', link_with : shlib2)
+test('runtest', exe)

test cases/failing/33 exe static shared/prog.c

@@ -0,0 +1,10 @@
+int shlibfunc2();
+int statlibfunc();
+
+int main(int argc, char **argv) {
+    if (statlibfunc() != 42)
+        return 1;
+    if (shlibfunc2() != 24)
+        return 1;
+    return 0;
+}

test cases/failing/33 exe static shared/shlib2.c

@@ -0,0 +1,16 @@
+#if defined _WIN32 || defined __CYGWIN__
+  #define DLL_PUBLIC __declspec(dllexport)
+#else
+  #if defined __GNUC__
+    #define DLL_PUBLIC __attribute__ ((visibility("default")))
+  #else
+    #pragma message ("Compiler does not support symbol visibility.")
+    #define DLL_PUBLIC
+  #endif
+#endif
+
+int statlibfunc(void);
+
+int DLL_PUBLIC shlibfunc2(void) {
+    return 24;
+}

test cases/failing/33 exe static shared/stat.c

@@ -0,0 +1,3 @@
+int statlibfunc() {
+    return 42;
+}