Added find_library method and deprecated the standalone version. Closes #396.

mesonbuild/compilers.py

@@ -190,6 +190,9 @@ class Compiler():
     def unix_compile_flags_to_native(self, args):
         return args
 
+    def find_library(self, libname):
+        raise EnvironmentException('Language {} does not support library finding.'.format(self.language))
+
 class CCompiler(Compiler):
     def __init__(self, exelist, version, is_cross, exe_wrapper=None):
         super().__init__(exelist, version)
@@ -563,6 +566,16 @@ void bar() {
 '''
         return self.compiles(templ % (prefix, typename), extra_args)
 
+    def find_library(self, libname):
+        code = '''int main(int argc, char **argv) {
+    return 0;
+}
+        '''
+        linkarg = '-l' + libname
+        if self.links(code, extra_args=[linkarg]):
+            return linkarg
+        return None
+
     def thread_flags(self):
         return ['-pthread']
 

mesonbuild/dependencies.py

@@ -388,7 +388,14 @@ class ExternalLibrary(Dependency):
     def __init__(self, name, fullpath=None, silent=False):
         super().__init__()
         self.name = name
-        self.fullpath = fullpath
+        # Rename fullpath to link_args once standalone find_library() gets removed.
+        if fullpath is not None:
+            if isinstance(fullpath, list):
+                self.fullpath = fullpath
+            else:
+                self.fullpath = [fullpath]
+        else:
+            self.fullpath = fullpath
         if not silent:
             if self.found():
                 mlog.log('Library', mlog.bold(name), 'found:', mlog.green('YES'),
@@ -401,7 +408,7 @@ class ExternalLibrary(Dependency):
 
     def get_link_args(self):
         if self.found():
-            return [self.fullpath]
+            return self.fullpath
         return []
 
 class BoostDependency(Dependency):

mesonbuild/interpreter.py

@@ -27,6 +27,8 @@ from functools import wraps
 
 import importlib
 
+find_lib_deprecation_printed = False
+
 class InterpreterException(coredata.MesonException):
     pass
 
@@ -581,6 +583,7 @@ class CompilerHolder(InterpreterObject):
                              'alignment' : self.alignment_method,
                              'version' : self.version_method,
                              'cmd_array' : self.cmd_array_method,
+                             'find_library': self.find_library_method,
                             })
 
     def version_method(self, args, kwargs):
@@ -750,6 +753,19 @@ class CompilerHolder(InterpreterObject):
         mlog.log('Has header "%s":' % string, h)
         return haz
 
+    def find_library_method(self, args, kwargs):
+        if len(args) != 1:
+            raise InterpreterException('find_library method takes one argument.')
+        libname = args[0]
+        if not isinstance(libname, str):
+            raise InterpreterException('Library name not a string.')
+        required = kwargs.get('required', True)
+        if not isinstance(required, bool):
+            raise InterpreterException('required must be boolean.')
+        linkarg = self.compiler.find_library(libname)
+        lib = dependencies.ExternalLibrary(libname, linkarg)
+        return ExternalLibraryHolder(lib)
+
 class ModuleState:
     pass
 
@@ -1526,6 +1542,10 @@ class Interpreter():
         return progobj
 
     def func_find_library(self, node, args, kwargs):
+        global find_lib_deprecation_printed
+        if not find_lib_deprecation_printed:
+            find_lib_deprecation_printed = True
+            mlog.log(mlog.red('DEPRECATION:'), 'find_library() is deprecated, use the corresponding method in compiler object instead.')
         self.validate_arguments(args, 1, [str])
         required = kwargs.get('required', True)
         if not isinstance(required, bool):

test cases/linuxlike/2 external library/meson.build

@@ -1,6 +1,8 @@
 project('external library', 'c')
 
-zlib = find_library('z')
+cc = meson.get_compiler('c')
+zlib = find_library('z') # DEPRECATED
+zlib2 = cc.find_library('z') # The modern way.
 
 # Verify that link testing works.
 linkcode = '''#include<zlib.h>
@@ -16,13 +18,16 @@ int main(int argc, char **argv) {
   return ptr == 0;
 }
 '''
-cc = meson.get_compiler('c')
+
 assert(cc.links(linkcode, args : '-lz', name : 'Test link against zlib'), 'Linking test failed.')
 assert(not cc.links(nolinkcode, name : 'Failing link'), 'Linking succeeded when it should have failed.')
 
 e = executable('zprog', 'prog.c', dependencies : zlib)
 test('libtest', e)
 
+e2 = executable('zprog_alt', 'prog.c', dependencies : zlib2)
+test('libtest_alt', e2)
+
 # Test that ext deps work via an internal dep.
 intdep = declare_dependency(dependencies : zlib)
 exe2 = executable('zprog2', 'prog.c', dependencies : intdep)