Get library name patterns with proper prefixes and suffixes on OS/2

mesonbuild/compilers/mixins/clike.py

@@ -990,9 +990,24 @@ def symbols_have_underscore_prefix(self, env: 'Environment') -> bool:
 
     def _get_patterns(self, env: 'Environment', prefixes: T.List[str], suffixes: T.List[str], shared: bool = False) -> T.List[str]:
         patterns: T.List[str] = []
-        for p in prefixes:
+        if env.machines[self.for_machine].is_os2():
+            # On OS/2, search order for shared libs is
+            #   1. libfoo_dll.a
+            #   2. foo_dll.a
+            #   3. libfoo.a
+            #   4. foo.a
+            #   5. foo.dll
+            # For static libs, `_s' is used instead of `_dll'.
             for s in suffixes:
-                patterns.append(p + '{}.' + s)
+                for p in prefixes:
+                    if s.startswith('_dll.') or s.startswith('_s.'):
+                        patterns.append(p + '{}' + s)
+                    else:
+                        patterns.append(p + '{}.' + s)
+        else:
+            for p in prefixes:
+                for s in suffixes:
+                    patterns.append(p + '{}.' + s)
         if shared and env.machines[self.for_machine].is_openbsd():
             # Shared libraries on OpenBSD can be named libfoo.so.X.Y:
             # https://www.openbsd.org/faq/ports/specialtopics.html#SharedLibs
@@ -1015,7 +1030,9 @@ def get_library_naming(self, env: 'Environment', libtype: LibType, strict: bool
         # people depend on it. Also, some people use prebuilt `foo.so` instead
         # of `libfoo.so` for unknown reasons, and may also want to create
         # `foo.so` by setting name_prefix to ''
-        if strict and not isinstance(self, VisualStudioLikeCompiler): # lib prefix is not usually used with msvc
+        # lib prefix is not usually used with msvc and OS/2
+        if strict and not isinstance(self, VisualStudioLikeCompiler) \
+          and not env.machines[self.for_machine].is_os2():
             prefixes = ['lib']
         else:
             prefixes = ['lib', '']
@@ -1038,6 +1055,14 @@ def get_library_naming(self, env: 'Environment', libtype: LibType, strict: bool
             # TI C28x compilers can use both extensions for static or dynamic libs.
             stlibext = ['a', 'lib']
             shlibext = ['dll', 'so']
+        elif env.machines[self.for_machine].is_os2():
+            from ...options import OptionKey
+            if env.coredata.get_option(OptionKey('emxomf')):
+                stlibext = ['_s.lib', '_s.a', 'lib', 'a']
+                shlibext = ['_dll.lib', '_dll.a', 'lib', 'a', 'dll']
+            else:
+                stlibext = ['_s.a', 'a']
+                shlibext = ['_dll.a', 'a', 'dll']
         else:
             # Linux/BSDs
             shlibext = ['so']