From: Chuck Lever Date: Thu, 20 Nov 2025 20:15:52 +0000 (-0500) Subject: xdrgen: Generate "if" instead of "switch" for boolean union enumerators X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9654a0388a3abcfa51cb2d010a6624a6f1f46710;p=thirdparty%2Fkernel%2Flinux.git xdrgen: Generate "if" instead of "switch" for boolean union enumerators Eliminate this warning in code generated by xdrgen: fs/nfsd/nfs3xdr_gen.c:220:2: warning: switch condition has boolean value [-Wswitch-bool] 220 | switch (ptr->attributes_follow) { | ^ ~~~~~~~~~~~~~~~~~~~~~~ No more -Wswitch-bool warnings when compiling with W=1. The generated code is functionally equivalent but somewhat more idiomatic. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202511172336.Y75zj4v6-lkp@intel.com/ Signed-off-by: Chuck Lever --- diff --git a/tools/net/sunrpc/xdrgen/generators/union.py b/tools/net/sunrpc/xdrgen/generators/union.py index ad1f214ef22a9..d15837dae6515 100644 --- a/tools/net/sunrpc/xdrgen/generators/union.py +++ b/tools/net/sunrpc/xdrgen/generators/union.py @@ -84,6 +84,31 @@ def emit_union_switch_spec_decoder( print(template.render(name=node.name, type=node.spec.type_name)) +def emit_union_arm_decoder( + environment: Environment, node: _XdrCaseSpec +) -> None: + """Emit decoder for an XDR union's arm (data only, no case/break)""" + + if isinstance(node.arm, _XdrVoid): + return + if isinstance(node.arm, _XdrString): + type_name = "char *" + classifier = "" + else: + type_name = node.arm.spec.type_name + classifier = node.arm.spec.c_classifier + + assert isinstance(node.arm, (_XdrBasic, _XdrString)) + template = get_jinja2_template(environment, "decoder", node.arm.template) + print( + template.render( + name=node.arm.name, + type=type_name, + classifier=classifier, + ) + ) + + def emit_union_case_spec_decoder( environment: Environment, node: _XdrCaseSpec, big_endian_discriminant: bool ) -> None: @@ -151,19 +176,33 @@ def emit_union_decoder(environment: Environment, node: _XdrUnion) -> None: template = get_jinja2_template(environment, "decoder", "open") print(template.render(name=node.name)) - emit_union_switch_spec_decoder(environment, node.discriminant) + # For boolean discriminants, use if statement instead of switch + if node.discriminant.spec.type_name == "bool": + template = get_jinja2_template(environment, "decoder", "bool_spec") + print(template.render(name=node.discriminant.name, type=node.discriminant.spec.type_name)) - for case in node.cases: - emit_union_case_spec_decoder( - environment, - case, - node.discriminant.spec.type_name in big_endian, - ) + # Find and emit the TRUE case + for case in node.cases: + if case.values and case.values[0] == "TRUE": + emit_union_arm_decoder(environment, case) + break - emit_union_default_spec_decoder(environment, node) + template = get_jinja2_template(environment, "decoder", "close") + print(template.render()) + else: + emit_union_switch_spec_decoder(environment, node.discriminant) - template = get_jinja2_template(environment, "decoder", "close") - print(template.render()) + for case in node.cases: + emit_union_case_spec_decoder( + environment, + case, + node.discriminant.spec.type_name in big_endian, + ) + + emit_union_default_spec_decoder(environment, node) + + template = get_jinja2_template(environment, "decoder", "close") + print(template.render()) def emit_union_switch_spec_encoder( @@ -175,6 +214,28 @@ def emit_union_switch_spec_encoder( print(template.render(name=node.name, type=node.spec.type_name)) +def emit_union_arm_encoder( + environment: Environment, node: _XdrCaseSpec +) -> None: + """Emit encoder for an XDR union's arm (data only, no case/break)""" + + if isinstance(node.arm, _XdrVoid): + return + if isinstance(node.arm, _XdrString): + type_name = "char *" + else: + type_name = node.arm.spec.type_name + + assert isinstance(node.arm, (_XdrBasic, _XdrString)) + template = get_jinja2_template(environment, "encoder", node.arm.template) + print( + template.render( + name=node.arm.name, + type=type_name, + ) + ) + + def emit_union_case_spec_encoder( environment: Environment, node: _XdrCaseSpec, big_endian_discriminant: bool ) -> None: @@ -235,19 +296,33 @@ def emit_union_encoder(environment, node: _XdrUnion) -> None: template = get_jinja2_template(environment, "encoder", "open") print(template.render(name=node.name)) - emit_union_switch_spec_encoder(environment, node.discriminant) + # For boolean discriminants, use if statement instead of switch + if node.discriminant.spec.type_name == "bool": + template = get_jinja2_template(environment, "encoder", "bool_spec") + print(template.render(name=node.discriminant.name, type=node.discriminant.spec.type_name)) - for case in node.cases: - emit_union_case_spec_encoder( - environment, - case, - node.discriminant.spec.type_name in big_endian, - ) + # Find and emit the TRUE case + for case in node.cases: + if case.values and case.values[0] == "TRUE": + emit_union_arm_encoder(environment, case) + break - emit_union_default_spec_encoder(environment, node) + template = get_jinja2_template(environment, "encoder", "close") + print(template.render()) + else: + emit_union_switch_spec_encoder(environment, node.discriminant) - template = get_jinja2_template(environment, "encoder", "close") - print(template.render()) + for case in node.cases: + emit_union_case_spec_encoder( + environment, + case, + node.discriminant.spec.type_name in big_endian, + ) + + emit_union_default_spec_encoder(environment, node) + + template = get_jinja2_template(environment, "encoder", "close") + print(template.render()) def emit_union_maxsize(environment: Environment, node: _XdrUnion) -> None: diff --git a/tools/net/sunrpc/xdrgen/templates/C/union/decoder/bool_spec.j2 b/tools/net/sunrpc/xdrgen/templates/C/union/decoder/bool_spec.j2 new file mode 100644 index 0000000000000..05ad491f74af5 --- /dev/null +++ b/tools/net/sunrpc/xdrgen/templates/C/union/decoder/bool_spec.j2 @@ -0,0 +1,7 @@ +{# SPDX-License-Identifier: GPL-2.0 #} +{% if annotate %} + /* discriminant {{ name }} */ +{% endif %} + if (!xdrgen_decode_{{ type }}(xdr, &ptr->{{ name }})) + return false; + if (ptr->{{ name }}) { diff --git a/tools/net/sunrpc/xdrgen/templates/C/union/encoder/bool_spec.j2 b/tools/net/sunrpc/xdrgen/templates/C/union/encoder/bool_spec.j2 new file mode 100644 index 0000000000000..e5135ed6471c5 --- /dev/null +++ b/tools/net/sunrpc/xdrgen/templates/C/union/encoder/bool_spec.j2 @@ -0,0 +1,7 @@ +{# SPDX-License-Identifier: GPL-2.0 #} +{% if annotate %} + /* discriminant {{ name }} */ +{% endif %} + if (!xdrgen_encode_{{ type }}(xdr, ptr->{{ name }})) + return false; + if (ptr->{{ name }}) {