Merge pull request #3353 from xclaesse/has-link-argument

Add has_link_argument() and friends

7 files changed, 166 insertions, 80 deletions

diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index fad6a3c..42abe75 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -1508,7 +1508,11 @@ the following methods:
 
 - `first_supported_argument(list_of_strings)`, given a list of
   strings, returns the first argument that passes the `has_argument`
-  test above or an empty array if none pass.
+  test or an empty array if none pass.
+
+- `first_supported_link_argument(list_of_strings)` *(added 0.46.0)*, given a
+  list of strings, returns the first argument that passes the
+  `has_link_argument` test or an empty array if none pass.
 
 - `get_define(definename)` returns the given preprocessor symbol's
   value as a string or empty string if it is not defined.
@@ -1520,11 +1524,19 @@ the following methods:
   an array containing only the arguments supported by the compiler,
   as if `has_argument` were called on them individually.
 
+- `get_supported_link_arguments(list_of_string)` *(added 0.46.0)* returns
+  an array containing only the arguments supported by the linker,
+  as if `has_link_argument` were called on them individually.
+
 - `has_argument(argument_name)` returns true if the compiler accepts
   the specified command line argument, that is, can compile code
-  without erroring out or printing a warning about an unknown flag,
-  you can specify external dependencies to use with `dependencies`
-  keyword argument.
+  without erroring out or printing a warning about an unknown flag.
+
+- `has_link_argument(argument_name)` *(added 0.46.0)* returns true if the linker
+  accepts the specified command line argument, that is, can compile and link
+  code without erroring out or printing a warning about an unknown flag. Link
+  arguments will be passed to the compiler, so should usually have the `-Wl,`
+  prefix. On VisualStudio a `/link` argument will be prepended.
 
 - `has_function(funcname)` returns true if the given function is
   provided by the standard library or a library passed in with the
@@ -1559,6 +1571,10 @@ the following methods:
   `has_argument` but takes multiple arguments and uses them all in a
   single compiler invocation, available since 0.37.0.
 
+- `has_multi_link_arguments(arg1, arg2, arg3, ...)` *(added 0.46.0)* is the same
+  as `has_link_argument` but takes multiple arguments and uses them all in a
+  single compiler invocation.
+
 - `has_type(typename)` returns true if the specified token is a type,
   you can specify external dependencies to use with `dependencies`
   keyword argument.
diff --git a/docs/markdown/snippets/has-link-argument.md b/docs/markdown/snippets/has-link-argument.md
new file mode 100644
index 0000000..7beda63
--- /dev/null
+++ b/docs/markdown/snippets/has-link-argument.md
@@ -0,0 +1,9 @@
+## has_link_argument() and friends
+
+A new set of methods has been added on compiler objects to test if the linker
+supports given arguments.
+
+- `has_link_argument()`
+- `has_multi_link_arguments()`
+- `get_supported_link_arguments()`
+- `first_supported_link_argument()`
diff --git a/mesonbuild/compilers/c.py b/mesonbuild/compilers/c.py
index 0e474e7..1230e3f 100644
--- a/mesonbuild/compilers/c.py
+++ b/mesonbuild/compilers/c.py
@@ -323,25 +323,21 @@ class CCompiler(Compiler):
         args += extra_args
         return args
 
-    def compiles(self, code, env, extra_args=None, dependencies=None, mode='compile', want_output=False):
-        args = self._get_compiler_check_args(env, extra_args, dependencies, mode)
-        # We only want to compile; not link
-        with self.compile(code, args.to_native(), mode) as p:
+    def compiles(self, code, env, extra_args=None, dependencies=None, mode='compile'):
+        with self._build_wrapper(code, env, extra_args, dependencies, mode) as p:
             return p.returncode == 0
 
-    def _links_wrapper(self, code, env, extra_args, dependencies, want_output=False):
-        "Shares common code between self.links and self.run"
-        args = self._get_compiler_check_args(env, extra_args, dependencies, mode='link')
-        return self.compile(code, args, want_output=want_output)
+    def _build_wrapper(self, code, env, extra_args, dependencies=None, mode='compile', want_output=False):
+        args = self._get_compiler_check_args(env, extra_args, dependencies, mode)
+        return self.compile(code, args.to_native(), mode, want_output=want_output)
 
     def links(self, code, env, extra_args=None, dependencies=None):
-        with self._links_wrapper(code, env, extra_args, dependencies) as p:
-            return p.returncode == 0
+        return self.compiles(code, env, extra_args, dependencies, mode='link')
 
     def run(self, code, env, extra_args=None, dependencies=None):
         if self.is_cross and self.exe_wrapper is None:
             raise CrossNoRunException('Can not run test applications in this cross environment.')
-        with self._links_wrapper(code, env, extra_args, dependencies, True) as p:
+        with self._build_wrapper(code, env, extra_args, dependencies, mode='link', want_output=True) as p:
             if p.returncode != 0:
                 mlog.debug('Could not compile test file %s: %d\n' % (
                     p.input_name,
@@ -841,6 +837,12 @@ class CCompiler(Compiler):
             return []
         return ['-pthread']
 
+    def linker_to_compiler_args(self, args):
+        return args
+
+    def has_arguments(self, args, env, code, mode):
+        return self.compiles(code, env, extra_args=args, mode=mode)
+
     def has_multi_arguments(self, args, env):
         for arg in args[:]:
             # some compilers, e.g. GCC, don't warn for unsupported warning-disable
@@ -849,13 +851,21 @@ class CCompiler(Compiler):
             if arg.startswith('-Wno-'):
                     args.append('-W' + arg[5:])
             if arg.startswith('-Wl,'):
-                mlog.warning('''{} looks like a linker argument, but has_argument
-and other similar methods only support checking compiler arguments.
-Using them to check linker arguments are never supported, and results
-are likely to be wrong regardless of the compiler you are using.
-'''.format(arg))
-        return self.compiles('int i;\n', env, extra_args=args)
+                mlog.warning('{} looks like a linker argument, '
+                             'but has_argument and other similar methods only '
+                             'support checking compiler arguments. Using them '
+                             'to check linker arguments are never supported, '
+                             'and results are likely to be wrong regardless of '
+                             'the compiler you are using. has_link_argument or '
+                             'other similar method can be used instead.'
+                             .format(arg))
+        code = 'int i;\n'
+        return self.has_arguments(args, env, code, mode='compile')
 
+    def has_multi_link_arguments(self, args, env):
+        args = self.linker_to_compiler_args(args)
+        code = 'int main(int argc, char **argv) { return 0; }'
+        return self.has_arguments(args, env, code, mode='link')
 
 class ClangCCompiler(ClangCompiler, CCompiler):
     def __init__(self, exelist, version, clang_type, is_cross, exe_wrapper=None, **kwargs):
@@ -981,8 +991,8 @@ class IntelCCompiler(IntelCompiler, CCompiler):
     def get_std_shared_lib_link_args(self):
         return ['-shared']
 
-    def has_multi_arguments(self, args, env):
-        return super().has_multi_arguments(args + ['-diag-error', '10006'], env)
+    def has_arguments(self, args, env, code, mode):
+        return super().has_arguments(args + ['-diag-error', '10006'], env, code, mode)
 
 
 class VisualStudioCCompiler(CCompiler):
@@ -1066,6 +1076,9 @@ class VisualStudioCCompiler(CCompiler):
     def get_linker_search_args(self, dirname):
         return ['/LIBPATH:' + dirname]
 
+    def linker_to_compiler_args(self, args):
+        return ['/link'] + args
+
     def get_gui_app_args(self):
         return ['/SUBSYSTEM:WINDOWS']
 
@@ -1149,24 +1162,12 @@ class VisualStudioCCompiler(CCompiler):
     # Visual Studio is special. It ignores some arguments it does not
     # understand and you can't tell it to error out on those.
     # http://stackoverflow.com/questions/15259720/how-can-i-make-the-microsoft-c-compiler-treat-unknown-flags-as-errors-rather-t
-    def has_multi_arguments(self, args, env):
-        warning_text = '9002'
-        code = 'int i;\n'
-        (fd, srcname) = tempfile.mkstemp(suffix='.' + self.default_suffix)
-        os.close(fd)
-        with open(srcname, 'w') as ofile:
-            ofile.write(code)
-        # Read c_args/cpp_args/etc from the cross-info file (if needed)
-        extra_args = self.get_cross_extra_flags(env, link=False)
-        extra_args += self.get_compile_only_args()
-        commands = self.exelist + args + extra_args + [srcname]
-        mlog.debug('Running VS compile:')
-        mlog.debug('Command line: ', ' '.join(commands))
-        mlog.debug('Code:\n', code)
-        p, stdo, stde = Popen_safe(commands, cwd=os.path.dirname(srcname))
-        if p.returncode != 0:
-            return False
-        return not(warning_text in stde or warning_text in stdo)
+    def has_arguments(self, args, env, code, mode):
+        warning_text = '4044' if mode == 'link' else '9002'
+        with self._build_wrapper(code, env, extra_args=args, mode=mode) as p:
+            if p.returncode != 0:
+                return False
+            return not(warning_text in p.stde or warning_text in p.stdo)
 
     def get_compile_debugfile_args(self, rel_obj, pch=False):
         pdbarr = rel_obj.split('.')[:-1]
diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index 37326d8..a2c6668 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -745,20 +745,15 @@ class Compiler:
     def get_library_dirs(self):
         return []
 
-    def has_argument(self, arg, env):
-        return self.has_multi_arguments([arg], env)
-
     def has_multi_arguments(self, args, env):
         raise EnvironmentException(
             'Language {} does not support has_multi_arguments.'.format(
                 self.get_display_language()))
 
-    def get_supported_arguments(self, args, env):
-        supported_args = []
-        for arg in args:
-            if self.has_argument(arg, env):
-                supported_args.append(arg)
-        return supported_args
+    def has_multi_link_arguments(self, args, env):
+        raise EnvironmentException(
+            'Language {} does not support has_multi_link_arguments.'.format(
+                self.get_display_language()))
 
     def get_cross_extra_flags(self, environment, link):
         extra_flags = []
@@ -815,7 +810,6 @@ class Compiler:
                 # Construct the compiler command-line
                 commands = CompilerArgs(self)
                 commands.append(srcname)
-                commands += extra_args
                 commands += self.get_always_args()
                 if mode == 'compile':
                     commands += self.get_compile_only_args()
@@ -825,6 +819,10 @@ class Compiler:
                 else:
                     output = self._get_compile_output(tmpdirname, mode)
                     commands += self.get_output_args(output)
+                # extra_args must be last because it could contain '/link' to
+                # pass args to VisualStudio's linker. In that case everything
+                # in the command line after '/link' is given to the linker.
+                commands += extra_args
                 # Generate full command-line with the exelist
                 commands = self.get_exelist() + commands.to_native()
                 mlog.debug('Running compile:')
diff --git a/mesonbuild/compilers/cpp.py b/mesonbuild/compilers/cpp.py
index 8dd2306..4c48052 100644
--- a/mesonbuild/compilers/cpp.py
+++ b/mesonbuild/compilers/cpp.py
@@ -199,20 +199,10 @@ class IntelCPPCompiler(IntelCompiler, CPPCompiler):
     def get_option_link_args(self, options):
         return []
 
-    def has_multi_arguments(self, args, env):
-        for arg in args:
-            if arg.startswith('-Wl,'):
-                mlog.warning('''{} looks like a linker argument, but has_argument
-and other similar methods only support checking compiler arguments.
-Using them to check linker arguments are never supported, and results
-are likely to be wrong regardless of the compiler you are using.
-'''.format(arg))
-        return super().has_multi_arguments(args + ['-diag-error', '10006'], env)
-
 
 class VisualStudioCPPCompiler(VisualStudioCCompiler, CPPCompiler):
     def __init__(self, exelist, version, is_cross, exe_wrap, is_64):
-        self.language = 'cpp'
+        CPPCompiler.__init__(self, exelist, version, is_cross, exe_wrap)
         VisualStudioCCompiler.__init__(self, exelist, version, is_cross, exe_wrap, is_64)
         self.base_options = ['b_pch'] # FIXME add lto, pgo and the like
 
@@ -239,7 +229,7 @@ class VisualStudioCPPCompiler(VisualStudioCCompiler, CPPCompiler):
     def get_compiler_check_args(self):
         # Visual Studio C++ compiler doesn't support -fpermissive,
         # so just use the plain C args.
-        return super(VisualStudioCCompiler, self).get_compiler_check_args()
+        return VisualStudioCCompiler.get_compiler_check_args(self)
 
 
 class ArmCPPCompiler(ArmCompiler, CPPCompiler):
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index 2c92895..4fe879a 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -741,6 +741,10 @@ class CompilerHolder(InterpreterObject):
                              'has_multi_arguments': self.has_multi_arguments_method,
                              'get_supported_arguments': self.get_supported_arguments_method,
                              'first_supported_argument': self.first_supported_argument_method,
+                             'has_link_argument': self.has_link_argument_method,
+                             'has_multi_link_arguments': self.has_multi_link_arguments_method,
+                             'get_supported_link_arguments': self.get_supported_link_arguments_method,
+                             'first_supported_link_argument': self.first_supported_link_argument_method,
                              'unittest_args': self.unittest_args_method,
                              'symbols_have_underscore_prefix': self.symbols_have_underscore_prefix_method,
                              })
@@ -1183,14 +1187,8 @@ class CompilerHolder(InterpreterObject):
     def has_argument_method(self, args, kwargs):
         args = mesonlib.stringlistify(args)
         if len(args) != 1:
-            raise InterpreterException('Has_arg takes exactly one argument.')
-        result = self.compiler.has_argument(args[0], self.environment)
-        if result:
-            h = mlog.green('YES')
-        else:
-            h = mlog.red('NO')
-        mlog.log('Compiler for {} supports argument {}:'.format(self.compiler.get_display_language(), args[0]), h)
-        return result
+            raise InterpreterException('has_argument takes exactly one argument.')
+        return self.has_multi_arguments_method(args, kwargs)
 
     @permittedMethodKwargs({})
     def has_multi_arguments_method(self, args, kwargs):
@@ -1209,26 +1207,58 @@ class CompilerHolder(InterpreterObject):
     @permittedMethodKwargs({})
     def get_supported_arguments_method(self, args, kwargs):
         args = mesonlib.stringlistify(args)
-        result = self.compiler.get_supported_arguments(args, self.environment)
-        if len(result) == len(args):
+        supported_args = []
+        for arg in args:
+            if self.has_argument_method(arg, kwargs):
+                supported_args.append(arg)
+        return supported_args
+
+    @permittedMethodKwargs({})
+    def first_supported_argument_method(self, args, kwargs):
+        for i in mesonlib.stringlistify(args):
+            if self.has_argument_method(i, kwargs):
+                mlog.log('First supported argument:', mlog.bold(i))
+                return [i]
+        mlog.log('First supported argument:', mlog.red('None'))
+        return []
+
+    @permittedMethodKwargs({})
+    def has_link_argument_method(self, args, kwargs):
+        args = mesonlib.stringlistify(args)
+        if len(args) != 1:
+            raise InterpreterException('has_link_argument takes exactly one argument.')
+        return self.has_multi_link_arguments_method(args, kwargs)
+
+    @permittedMethodKwargs({})
+    def has_multi_link_arguments_method(self, args, kwargs):
+        args = mesonlib.stringlistify(args)
+        result = self.compiler.has_multi_link_arguments(args, self.environment)
+        if result:
             h = mlog.green('YES')
-        elif len(result) > 0:
-            h = mlog.yellow('SOME')
         else:
             h = mlog.red('NO')
         mlog.log(
-            'Compiler for {} supports arguments {}:'.format(
+            'Compiler for {} supports link arguments {}:'.format(
                 self.compiler.get_display_language(), ' '.join(args)),
             h)
         return result
 
     @permittedMethodKwargs({})
-    def first_supported_argument_method(self, args, kwargs):
+    def get_supported_link_arguments_method(self, args, kwargs):
+        args = mesonlib.stringlistify(args)
+        supported_args = []
+        for arg in args:
+            if self.has_link_argument_method(arg, kwargs):
+                supported_args.append(arg)
+        return supported_args
+
+    @permittedMethodKwargs({})
+    def first_supported_link_argument_method(self, args, kwargs):
         for i in mesonlib.stringlistify(args):
-            if self.compiler.has_argument(i, self.environment):
-                mlog.log('First supported argument:', mlog.bold(i))
+            if self.has_link_argument_method(i, kwargs):
+                mlog.log('First supported link argument:', mlog.bold(i))
                 return [i]
-        mlog.log('First supported argument:', mlog.red('None'))
+        mlog.log('First supported link argument:', mlog.red('None'))
         return []
 
 ModuleState = namedtuple('ModuleState', [
diff --git a/test cases/common/191 has link arg/meson.build b/test cases/common/191 has link arg/meson.build
new file mode 100644
index 0000000..255ff45
--- /dev/null
+++ b/test cases/common/191 has link arg/meson.build
@@ -0,0 +1,42 @@
+project('has link arg', 'c', 'cpp')
+
+cc = meson.get_compiler('c')
+cpp = meson.get_compiler('cpp')
+
+if cc.get_id() == 'msvc'
+  is_arg = '/OPT:REF'
+  useless = '/DEBUG'
+  isnt_arg = '/iambroken'
+else
+  is_arg = '-Wl,-Lfoo'
+  useless = '-Wl,-Lbar'
+  isnt_arg = '-Wl,-iambroken'
+endif
+
+assert(cc.has_link_argument(is_arg), 'Arg that should have worked does not work.')
+assert(not cc.has_link_argument(isnt_arg), 'Arg that should be broken is not.')
+
+assert(cpp.has_link_argument(is_arg), 'Arg that should have worked does not work.')
+assert(not cpp.has_link_argument(isnt_arg), 'Arg that should be broken is not.')
+
+assert(cc.get_supported_link_arguments([is_arg, isnt_arg, useless]) == [is_arg, useless], 'Arg filtering returned different result.')
+assert(cpp.get_supported_link_arguments([is_arg, isnt_arg, useless]) == [is_arg, useless], 'Arg filtering returned different result.')
+
+# Have useless at the end to ensure that the search goes from front to back.
+l1 = cc.first_supported_link_argument([isnt_arg, is_arg, isnt_arg, useless])
+l2 = cc.first_supported_link_argument(isnt_arg, isnt_arg, isnt_arg)
+
+assert(l1.length() == 1, 'First supported returned wrong result.')
+assert(l1.get(0) == is_arg, 'First supported returned wrong argument.')
+assert(l2.length() == 0, 'First supported did not return empty array.')
+
+l1 = cpp.first_supported_link_argument([isnt_arg, is_arg, isnt_arg, useless])
+l2 = cpp.first_supported_link_argument(isnt_arg, isnt_arg, isnt_arg)
+
+assert(l1.length() == 1, 'First supported returned wrong result.')
+assert(l1.get(0) == is_arg, 'First supported returned wrong argument.')
+assert(l2.length() == 0, 'First supported did not return empty array.')
+
+assert(not cc.has_multi_link_arguments([isnt_arg, is_arg]), 'Arg that should be broken is not.')
+assert(cc.has_multi_link_arguments(is_arg), 'Arg that should have worked does not work.')
+assert(cc.has_multi_link_arguments([useless, is_arg]), 'Arg that should have worked does not work.')