Introduce static_to_shared_library function (#6092)

The static_to_shared_library function takes an existing static library
and produces a shared library based on it.

1 files changed, 98 insertions, 0 deletions

diff --git a/lib/spack/spack/build_environment.py b/lib/spack/spack/build_environment.py
index 0a9bd22de7..f1cf0d5049 100644
--- a/lib/spack/spack/build_environment.py
+++ b/lib/spack/spack/build_environment.py
@@ -373,6 +373,104 @@ def set_module_variables_for_package(pkg, module):
     # Platform-specific library suffix.
     m.dso_suffix = dso_suffix
 
+    def static_to_shared_library(static_lib, shared_lib=None, **kwargs):
+        compiler_path = kwargs.get('compiler', m.spack_cc)
+        compiler = Executable(compiler_path)
+
+        return _static_to_shared_library(pkg.spec.architecture, compiler,
+                                         static_lib, shared_lib, **kwargs)
+
+    m.static_to_shared_library = static_to_shared_library
+
+
+def _static_to_shared_library(arch, compiler, static_lib, shared_lib=None,
+                              **kwargs):
+    """
+    Converts a static library to a shared library. The static library has to
+    be built with PIC for the conversion to work.
+
+    Parameters:
+        static_lib (str): Path to the static library.
+        shared_lib (str): Path to the shared library. Default is to derive
+                          from the static library's path.
+
+    Keyword arguments:
+        compiler (str): Path to the compiler. Default is spack_cc.
+        compiler_output: Where to print compiler output to.
+        arguments (str list): Additional arguments for the compiler.
+        version (str): Library version. Default is unspecified.
+        compat_version (str): Library compatibility version. Default is
+                              version.
+    """
+    compiler_output = kwargs.get('compiler_output', None)
+    arguments = kwargs.get('arguments', [])
+    version = kwargs.get('version', None)
+    compat_version = kwargs.get('compat_version', version)
+
+    if not shared_lib:
+        shared_lib = '{0}.{1}'.format(os.path.splitext(static_lib)[0],
+                                      dso_suffix)
+
+    compiler_args = []
+
+    # TODO: Compiler arguments should not be hardcoded but provided by
+    #       the different compiler classes.
+    if 'linux' in arch:
+        soname = os.path.basename(shared_lib)
+
+        if compat_version:
+            soname += '.{0}'.format(compat_version)
+
+        compiler_args = [
+            '-shared',
+            '-Wl,-soname,{0}'.format(soname),
+            '-Wl,--whole-archive',
+            static_lib,
+            '-Wl,--no-whole-archive'
+        ]
+    elif 'darwin' in arch:
+        install_name = shared_lib
+
+        if compat_version:
+            install_name += '.{0}'.format(compat_version)
+
+        compiler_args = [
+            '-dynamiclib',
+            '-install_name {0}'.format(install_name),
+            '-Wl,-force_load,{0}'.format(static_lib)
+        ]
+
+        if compat_version:
+            compiler_args.append('-compatibility_version {0}'.format(
+                compat_version))
+
+        if version:
+            compiler_args.append('-current_version {0}'.format(version))
+
+    if len(arguments) > 0:
+        compiler_args.extend(arguments)
+
+    shared_lib_base = shared_lib
+
+    if version:
+        shared_lib += '.{0}'.format(version)
+    elif compat_version:
+        shared_lib += '.{0}'.format(compat_version)
+
+    compiler_args.extend(['-o', shared_lib])
+
+    # Create symlinks for version and compat_version
+    shared_lib_link = os.path.basename(shared_lib)
+
+    if version or compat_version:
+        os.symlink(shared_lib_link, shared_lib_base)
+
+    if compat_version and compat_version != version:
+        os.symlink(shared_lib_link, '{0}.{1}'.format(shared_lib_base,
+                                                     compat_version))
+
+    return compiler(*compiler_args, output=compiler_output)
+
 
 def get_rpath_deps(pkg):
     """Return immediate or transitive RPATHs depending on the package."""