feat: configurable ldflags (#1226)

foreign_cc/configure.bzl

@@ -74,7 +74,6 @@ def _create_configure_script(configureParameters):
 
     user_env = expand_locations_and_make_variables(ctx, ctx.attr.env, "env", data)
 
-    make_commands = []
     prefix = "{} ".format(expand_locations_and_make_variables(ctx, attrs.tool_prefix, "tool_prefix", data)) if attrs.tool_prefix else ""
     configure_prefix = "{} ".format(expand_locations_and_make_variables(ctx, ctx.attr.configure_prefix, "configure_prefix", data)) if ctx.attr.configure_prefix else ""
     configure_options = [expand_locations_and_make_variables(ctx, option, "configure_option", data) for option in ctx.attr.configure_options] if ctx.attr.configure_options else []
@@ -83,15 +82,6 @@ def _create_configure_script(configureParameters):
     if xcompile_options:
         configure_options.extend(xcompile_options)
 
-    for target in ctx.attr.targets:
-        # Configure will have generated sources into `$BUILD_TMPDIR` so make sure we `cd` there
-        make_commands.append("{prefix}{make} {target} {args}".format(
-            prefix = prefix,
-            make = attrs.make_path,
-            args = args,
-            target = target,
-        ))
-
     configure = create_configure_script(
         workspace_name = ctx.workspace_name,
         tools = tools,
@@ -112,8 +102,12 @@ def _create_configure_script(configureParameters):
         autogen = ctx.attr.autogen,
         autogen_command = ctx.attr.autogen_command,
         autogen_options = ctx.attr.autogen_options,
-        make_commands = make_commands,
+        make_prefix = prefix,
         make_path = attrs.make_path,
+        make_targets = ctx.attr.targets,
+        make_args = args,
+        executable_ldflags_vars = ctx.attr.executable_ldflags_vars,
+        shared_ldflags_vars = ctx.attr.shared_ldflags_vars,
     )
     return define_install_prefix + configure
 
@@ -198,6 +192,15 @@ def _attrs():
             ),
             default = False,
         ),
+        "executable_ldflags_vars": attr.string_list(
+            doc = (
+                "A list of variable names use as LDFLAGS for executables. These variables " +
+                "will be passed to the make command as make vars and overwrite what is defined in " +
+                "the Makefile."
+            ),
+            mandatory = False,
+            default = [],
+        ),
         "install_prefix": attr.string(
             doc = (
                 "Install prefix, i.e. relative path to where to install the result of the build. " +
@@ -212,6 +215,15 @@ def _attrs():
             mandatory = False,
             default = "--prefix=",
         ),
+        "shared_ldflags_vars": attr.string_list(
+            doc = (
+                "A list of variable names use as LDFLAGS for shared libraries. These variables " +
+                "will be passed to the make command as make vars and overwrite what is defined in " +
+                "the Makefile."
+            ),
+            mandatory = False,
+            default = [],
+        ),
         "targets": attr.string_list(
             doc = (
                 "A list of targets within the foreign build system to produce. An empty string (`\"\"`) will result in " +

foreign_cc/make.bzl

@@ -74,7 +74,13 @@ def _create_make_script(configureParameters):
         deps = ctx.attr.deps,
         inputs = inputs,
         env_vars = user_env,
-        make_commands = make_commands,
+        make_prefix = prefix,
+        make_path = attrs.make_path,
+        make_targets = ctx.attr.targets,
+        make_args = args,
+        make_install_prefix = ctx.attr.install_prefix,
+        executable_ldflags_vars = ctx.attr.executable_ldflags_vars,
+        shared_ldflags_vars = ctx.attr.shared_ldflags_vars,
     )
 
 def _attrs():
@@ -83,6 +89,15 @@ def _attrs():
         "args": attr.string_list(
             doc = "A list of arguments to pass to the call to `make`",
         ),
+        "executable_ldflags_vars": attr.string_list(
+            doc = (
+                "A string list of variable names use as LDFLAGS for executables. These variables " +
+                "will be passed to the make command as make vars and overwrite what is defined in " +
+                "the Makefile."
+            ),
+            mandatory = False,
+            default = [],
+        ),
         "install_prefix": attr.string(
             doc = (
                 "Install prefix, i.e. relative path to where to install the result of the build. " +
@@ -91,6 +106,15 @@ def _attrs():
             mandatory = False,
             default = "$$INSTALLDIR$$",
         ),
+        "shared_ldflags_vars": attr.string_list(
+            doc = (
+                "A string list of variable names use as LDFLAGS for shared libraries. These variables " +
+                "will be passed to the make command as make vars and overwrite what is defined in " +
+                "the Makefile."
+            ),
+            mandatory = False,
+            default = [],
+        ),
         "targets": attr.string_list(
             doc = (
                 "A list of targets within the foreign build system to produce. An empty string (`\"\"`) will result in " +

foreign_cc/private/configure_script.bzl

@@ -1,5 +1,5 @@
 # buildifier: disable=module-docstring
-load(":make_env_vars.bzl", "get_make_env_vars")
+load(":make_env_vars.bzl", "get_ldflags_make_vars", "get_make_env_vars")
 load(":make_script.bzl", "pkgconfig_script")
 
 # buildifier: disable=function-docstring
@@ -23,8 +23,12 @@ def create_configure_script(
         autogen,
         autogen_command,
         autogen_options,
+        make_prefix,
         make_path,
-        make_commands):
+        make_targets,
+        make_args,
+        executable_ldflags_vars,
+        shared_ldflags_vars):
     ext_build_dirs = inputs.ext_build_dirs
 
     script = pkgconfig_script(ext_build_dirs)
@@ -77,6 +81,18 @@ def create_configure_script(
         user_options = " ".join(user_options),
     ))
 
+    ldflags_make_vars = get_ldflags_make_vars(executable_ldflags_vars, shared_ldflags_vars, workspace_name, flags, env_vars, deps, inputs)
+
+    make_commands = []
+    for target in make_targets:
+        make_commands.append("{prefix}{make} {make_vars} {target} {args}".format(
+            prefix = make_prefix,
+            make = make_path,
+            make_vars = ldflags_make_vars,
+            args = make_args,
+            target = target,
+        ))
+
     script.extend(make_commands)
     script.append("##disable_tracing##")
 

foreign_cc/private/make_env_vars.bzl

@@ -34,6 +34,24 @@ def get_make_env_vars(
     return " ".join(["{}=\"{}\""
         .format(key, _join_flags_list(workspace_name, vars[key])) for key in vars])
 
+# buildifier: disable=function-docstring
+def get_ldflags_make_vars(
+        executable_ldflags_vars,
+        shared_ldflags_vars,
+        workspace_name,
+        flags,
+        user_vars,
+        deps,
+        inputs):
+    vars = _get_ldflags_vars(executable_ldflags_vars, shared_ldflags_vars, flags, user_vars)
+
+    deps_flags = _define_deps_flags(deps, inputs)
+    for key in vars.keys():
+        vars[key] = vars[key] + deps_flags.libs
+
+    return " ".join(["{}=\"{}\""
+        .format(key, _join_flags_list(workspace_name, vars[key])) for key in vars])
+
 def _define_deps_flags(deps, inputs):
     # It is very important to keep the order for the linker => put them into list
     lib_dirs = []
@@ -99,17 +117,7 @@ _MAKE_TOOLS = {
 }
 
 def _get_make_variables(workspace_name, tools, flags, user_env_vars, make_commands):
-    vars = {}
+    vars = _merge_env_vars(flags, _MAKE_FLAGS, user_env_vars)
-
-    for flag in _MAKE_FLAGS:
-        toolchain_flags = getattr(flags, _MAKE_FLAGS[flag], [])
-        user_flags = [
-            user_flag
-            for user_flag in user_env_vars.get(flag, "").split(" ")
-            if user_flag
-        ]
-        if toolchain_flags or user_flags:
-            vars[flag] = toolchain_flags + user_flags
 
     # Add user defined CPPFLAGS
     user_cpp_flags = [flag for flag in user_env_vars.get("CPPFLAGS", "").split(" ") if flag]
@@ -146,6 +154,34 @@ def _get_make_variables(workspace_name, tools, flags, user_env_vars, make_comman
 
     return vars
 
+def _get_ldflags_vars(
+        executable_ldflags_vars,
+        shared_ldflags_vars,
+        flags,
+        user_env_vars):
+    executable_ldflags = {var: "cxx_linker_executable" for var in executable_ldflags_vars}
+    shared_ldflags = {var: "cxx_linker_shared" for var in shared_ldflags_vars}
+
+    linker_make_flags = {}
+    for ldflags in [executable_ldflags, shared_ldflags]:
+        linker_make_flags.update(ldflags)
+
+    return _merge_env_vars(flags, linker_make_flags, user_env_vars)
+
+def _merge_env_vars(flags, make_flags, user_env_vars):
+    vars = {}
+
+    for flag in make_flags:
+        toolchain_flags = getattr(flags, make_flags[flag], [])
+        user_flags = [
+            user_flag
+            for user_flag in user_env_vars.get(flag, "").split(" ")
+            if user_flag
+        ]
+        if toolchain_flags or user_flags:
+            vars[flag] = toolchain_flags + user_flags
+    return vars
+
 def _absolutize(workspace_name, text, force = False):
     return absolutize_path_in_str(workspace_name, "$$EXT_BUILD_ROOT$$/", text, force)
 

foreign_cc/private/make_script.bzl

@@ -1,6 +1,6 @@
 """A module for creating the build script for `make` builds"""
 
-load(":make_env_vars.bzl", "get_make_env_vars")
+load(":make_env_vars.bzl", "get_ldflags_make_vars", "get_make_env_vars")
 
 # buildifier: disable=function-docstring
 def create_make_script(
@@ -11,7 +11,13 @@ def create_make_script(
         env_vars,
         deps,
         inputs,
-        make_commands):
+        make_prefix,
+        make_path,
+        make_targets,
+        make_args,
+        make_install_prefix,
+        executable_ldflags_vars,
+        shared_ldflags_vars):
     ext_build_dirs = inputs.ext_build_dirs
 
     script = pkgconfig_script(ext_build_dirs)
@@ -19,7 +25,22 @@ def create_make_script(
     script.append("##symlink_contents_to_dir## $$EXT_BUILD_ROOT$$/{} $$BUILD_TMPDIR$$ False".format(root))
 
     script.append("##enable_tracing##")
+
+    ldflags_make_vars = get_ldflags_make_vars(executable_ldflags_vars, shared_ldflags_vars, workspace_name, flags, env_vars, deps, inputs)
+
+    make_commands = []
+    for target in make_targets:
+        make_commands.append("{prefix}{make} {make_vars} {target} {args} PREFIX={install_prefix}".format(
+            prefix = make_prefix,
+            make = make_path,
+            make_vars = ldflags_make_vars,
+            args = make_args,
+            target = target,
+            install_prefix = make_install_prefix,
+        ))
+
     configure_vars = get_make_env_vars(workspace_name, tools, flags, env_vars, deps, inputs, make_commands)
+
     script.extend(["{env_vars} {command}".format(
         env_vars = configure_vars,
         command = command,