cc_binary() cannot be called during the analysis phase - bazel

Question

I've tried to convert a bazel macro to a rule, so it's parsing is done now on analysis time rather than on loading time, this makes calling native.cc_binary impossible to do
def _emcc_binary(ctx):
includejs = False
includehtml = False
linkopts = list(ctx.attr.linkopts)
linkopts.append("-s EXTRA_EXPORTED_RUNTIME_METHODS='[\"ccall\", \"cwrap\"]'")
if ctx.attr.name.endswith(".html"):
basename = ctx.attr.name[:-5]
includehtml = True
includejs = True
elif ctx.attr.name.endswith(".js"):
basename = ctx.attr.name[:-3]
includejs = True
outputs = []
if includejs:
outputs.append(basename + ".js")
if ctx.attr.wasm:
outputs.append(basename + ".wasm")
if ctx.attr.memory_init_file:
outputs.append(basename + ".mem")
if ctx.attr.worker:
outputs.append(basename + ".worker.js")
linkopts.append("--proxy-to-worker")
if includehtml:
outputs.append(basename + ".html")
if not ctx.attr.wasm:
linkopts.append("-s WASM=0")
linkopts.append("--memory-init-file %d" % ctx.attr.memory_init_file)
if includejs:
tarfile = ctx.attr.name + ".tar"
# we'll generate a tarfile and extract multiple outputs
native.cc_binary(name = tarfile, linkopts = linkopts, **ctx.attr.kwargs)
native.genrule(
name = "emcc_extract_" + tarfile,
srcs = [tarfile],
outs = outputs,
output_to_bindir = 1,
testonly = ctx.attr.kwargs.get("testonly"),
cmd = """
tar xvf $< -C "$(#D)"/$$(dirname "%s")
""" % [outputs[0]],
)
else:
native.cc_binary(name = ctx.attr.name, linkopts = linkopts, **ctx.attr.kwargs)
# we'll generate a tarfile and extract multiple outputs
emcc_binary = rule(
implementation = _emcc_binary,
attrs = {
"memory_init_file": attr.int(default = 0),
"wasm": attr.bool(default = True),
"worker": attr.bool(default = False),
"srcs": attr.label_list(allow_files = True),
"linkopts": attr.string_list(),
"noop": attr.bool(default = False),
"kwargs": attr.label_keyed_string_dict()
},
)
output:
cc_binary() cannot be called during the analysis phase
ERROR: Analysis of target '//tests:hi.js' failed; build aborted: Analysis of target '//tests:hi.js' failed; build aborted

Answer 1

Correct, rules cannot be called from the implementations of other rules. Typically the solution is to use both rules and macros, where the macro creates and wires up the other rules (including your custom Starlark rules) where necessary.
Looking over your code, it's not clear that you really need to change the macro to a rule. Might be helpful if you could describe your end goal (feel free to reach out to bazel-discuss if you'd like more help here). That said, if you really wanted, you can replace native.genrule with actions and native.cc_binary with cc_common, which are designed to work with rules.