Configurable settings for opt_level, debug_info and strip_level

rust/private/debug_info.bzl

@@ -0,0 +1,26 @@
+"""A module defining Rust debug-info rules"""
+
+load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
+
+RustDebugInfoInfo = provider(
+    doc = "A provider describing the debug-info settings per compilation mode.",
+    fields = {
+        "levels": "dict[str, str]: Mapping of compilation mode to debug-info string.",
+    },
+)
+
+def _rust_debug_info_flag_impl(ctx):
+    levels = {}
+    for mode in ("dbg", "fastbuild", "opt"):
+        levels[mode] = getattr(ctx.attr, mode)[BuildSettingInfo].value
+    return [RustDebugInfoInfo(levels = levels)]
+
+rust_debug_info_flag = rule(
+    doc = "Aggregates the three per-mode debug-info flags into a single RustDebugInfoInfo provider. Valid values are defined by rustc: https://doc.rust-lang.org/rustc/codegen-options/index.html#debuginfo.",
+    implementation = _rust_debug_info_flag_impl,
+    attrs = {
+        "dbg": attr.label(default = "//rust/settings:debug_info_dbg"),
+        "fastbuild": attr.label(default = "//rust/settings:debug_info_fastbuild"),
+        "opt": attr.label(default = "//rust/settings:debug_info_opt"),
+    },
+)

rust/private/opt_level.bzl

@@ -0,0 +1,26 @@
+"""A module defining Rust opt-level rules"""
+
+load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
+
+RustOptLevelInfo = provider(
+    doc = "A provider describing the opt-level settings per compilation mode.",
+    fields = {
+        "levels": "dict[str, str]: Mapping of compilation mode to opt-level string.",
+    },
+)
+
+def _rust_opt_level_flag_impl(ctx):
+    levels = {}
+    for mode in ("dbg", "fastbuild", "opt"):
+        levels[mode] = getattr(ctx.attr, mode)[BuildSettingInfo].value
+    return [RustOptLevelInfo(levels = levels)]
+
+rust_opt_level_flag = rule(
+    doc = "Aggregates the three per-mode opt-level flags into a single RustOptLevelInfo provider. Valid values are defined by rustc: https://doc.rust-lang.org/rustc/codegen-options/index.html#opt-level",
+    implementation = _rust_opt_level_flag_impl,
+    attrs = {
+        "dbg": attr.label(default = "//rust/settings:opt_level_dbg"),
+        "fastbuild": attr.label(default = "//rust/settings:opt_level_fastbuild"),
+        "opt": attr.label(default = "//rust/settings:opt_level_opt"),
+    },
+)

rust/private/repositories.bzl

@@ -64,6 +64,7 @@ def rust_register_toolchains(
         extra_rustc_flags = None,
         extra_exec_rustc_flags = None,
         opt_level = None,
+        debug_info = None,
         strip_level = None,
         urls = DEFAULT_STATIC_RUST_URL_TEMPLATES,
         versions = _RUST_TOOLCHAIN_VERSIONS,
@@ -103,6 +104,7 @@ def rust_register_toolchains(
         extra_rustc_flags (dict, list, optional): Dictionary of target triples to list of extra flags to pass to rustc in non-exec configuration.
         extra_exec_rustc_flags (dict, list, optional): Dictionary of target triples to list of extra flags to pass to rustc in exec configuration.
         opt_level (dict, optional): Rustc optimization levels. For more details see the documentation for `rust_toolchain.opt_level`.
+        debug_info (dict, optional): Dictionary of target triples to debug info config.
         strip_level (dict, dict, optional): Dictionary of target triples to strip config.
         urls (list, optional): A list of mirror urls containing the tools from the Rust-lang static file server. These must contain the '{}' used to substitute the tool being fetched (using .format).
         versions (list, optional): A list of toolchain versions to download. This parameter only accepts one versions
@@ -187,6 +189,7 @@ def rust_register_toolchains(
             extra_rustc_flags = extra_rustc_flags,
             extra_exec_rustc_flags = extra_exec_rustc_flags,
             opt_level = opt_level_by_triple,
+            debug_info = debug_info,
             strip_level = strip_level,
             sha256s = sha256s,
             urls = urls,
@@ -275,6 +278,9 @@ _RUST_TOOLCHAIN_REPOSITORY_ATTRS = {
     "auth_patterns": attr.string_list(
         doc = "A list of patterns to match against urls for which the auth object should be used.",
     ),
+    "debug_info": attr.string_dict(
+        doc = "Rustc debug info levels. For more details see the documentation for `rust_toolchain.debug_info`.",
+    ),
     "dev_components": attr.bool(
         doc = "Whether to download the rustc-dev components (defaults to False). Requires version to be \"nightly\".",
         default = False,
@@ -483,6 +489,7 @@ def _rust_toolchain_tools_repository_impl(ctx):
         extra_rustc_flags = ctx.attr.extra_rustc_flags,
         extra_exec_rustc_flags = ctx.attr.extra_exec_rustc_flags,
         opt_level = ctx.attr.opt_level if ctx.attr.opt_level else None,
+        debug_info = ctx.attr.debug_info if ctx.attr.debug_info else None,
         strip_level = ctx.attr.strip_level if ctx.attr.strip_level else None,
         version = toolchain_version,
         channel = channel,
@@ -595,6 +602,7 @@ def rust_toolchain_repository(
         extra_rustc_flags = None,
         extra_exec_rustc_flags = None,
         opt_level = None,
+        debug_info = None,
         strip_level = None,
         sha256s = None,
         urls = DEFAULT_STATIC_RUST_URL_TEMPLATES,
@@ -627,6 +635,7 @@ def rust_toolchain_repository(
             Subject to Make variable expansion with respect to RUST_SYSROOT,
             RUST_SYSROOT_SHORT, RUSTC, etc.
         opt_level (dict, optional): Optimization level config for this toolchain.
+        debug_info (dict, optional): Debug info level config for this toolchain.
         strip_level (dict, optional): Strip level config for this toolchain.
         sha256s (str, optional): A dict associating tool subdirectories to sha256 hashes. See
             [rust_register_toolchains](#rust_register_toolchains) for more details.
@@ -660,6 +669,7 @@ def rust_toolchain_repository(
         extra_rustc_flags = extra_rustc_flags,
         extra_exec_rustc_flags = extra_exec_rustc_flags,
         opt_level = opt_level,
+        debug_info = debug_info,
         strip_level = strip_level,
         sha256s = sha256s,
         urls = urls,
@@ -993,6 +1003,7 @@ def rust_repository_set(
         extra_rustc_flags = None,
         extra_exec_rustc_flags = None,
         opt_level = None,
+        debug_info = None,
         strip_level = None,
         sha256s = None,
         urls = DEFAULT_STATIC_RUST_URL_TEMPLATES,
@@ -1026,6 +1037,7 @@ def rust_repository_set(
         extra_rustc_flags (dict, list, optional): Dictionary of target triples to list of extra flags to pass to rustc in non-exec configuration.
         extra_exec_rustc_flags (dict, list, optional): Dictionary of target triples to list of extra flags to pass to rustc in exec configuration.
         opt_level (dict, dict, optional): Dictionary of target triples to optimization config.
+        debug_info (dict, dict, optional): Dictionary of target triples to debug info config.
         strip_level (dict, dict, optional): Dictionary of target triples to strip config.
         sha256s (str, optional): A dict associating tool subdirectories to sha256 hashes. See
             [rust_register_toolchains](#rust_register_toolchains) for more details.
@@ -1083,6 +1095,7 @@ def rust_repository_set(
             extra_rustc_flags = toolchain_extra_rustc_flags,
             extra_exec_rustc_flags = toolchain_extra_exec_rustc_flags,
             opt_level = opt_level.get(toolchain.target_triple) if opt_level != None else None,
+            debug_info = debug_info.get(toolchain.target_triple) if debug_info != None else None,
             strip_level = strip_level.get(toolchain.target_triple) if strip_level != None else None,
             sha256s = sha256s,
             urls = urls,

rust/private/repository_utils.bzl

@@ -367,6 +367,7 @@ rust_toolchain(
     extra_rustc_flags = {extra_rustc_flags},
     extra_exec_rustc_flags = {extra_exec_rustc_flags},
     opt_level = {opt_level},
+    debug_info = {debug_info},
     strip_level = {strip_level},
     version = "{version}",
     channel = "{channel}",
@@ -393,6 +394,7 @@ def BUILD_for_rust_toolchain(
         extra_rustc_flags = None,
         extra_exec_rustc_flags = None,
         opt_level = None,
+        debug_info = None,
         strip_level = None):
     """Emits a toolchain declaration to match an existing compiler and stdlib.
 
@@ -418,6 +420,7 @@ def BUILD_for_rust_toolchain(
         extra_rustc_flags (list, optional): Extra flags to pass to rustc in non-exec configuration.
         extra_exec_rustc_flags (list, optional): Extra flags to pass to rustc in exec configuration.
         opt_level (dict, optional): Optimization level config for this toolchain.
+        debug_info (dict, optional): Debug info level config for this toolchain.
         strip_level (dict, optional): Strip level config for this toolchain.
 
     Returns:
@@ -480,6 +483,7 @@ def BUILD_for_rust_toolchain(
         extra_rustc_flags = extra_rustc_flags,
         extra_exec_rustc_flags = extra_exec_rustc_flags,
         opt_level = opt_level,
+        debug_info = debug_info,
         strip_level = strip_level,
         version = version,
         channel = channel,

rust/private/strip_level.bzl

@@ -0,0 +1,26 @@
+"""A module defining Rust strip-level rules"""
+
+load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
+
+RustStripLevelInfo = provider(
+    doc = "A provider describing the strip-level settings per compilation mode.",
+    fields = {
+        "levels": "dict[str, str]: Mapping of compilation mode to strip-level string.",
+    },
+)
+
+def _rust_strip_level_flag_impl(ctx):
+    levels = {}
+    for mode in ("dbg", "fastbuild", "opt"):
+        levels[mode] = getattr(ctx.attr, mode)[BuildSettingInfo].value
+    return [RustStripLevelInfo(levels = levels)]
+
+rust_strip_level_flag = rule(
+    doc = "Aggregates the three per-mode strip-level flags into a single RustStripLevelInfo provider. Valid values are defined by rustc: https://doc.rust-lang.org/rustc/codegen-options/index.html#strip",
+    implementation = _rust_strip_level_flag_impl,
+    attrs = {
+        "dbg": attr.label(default = "//rust/settings:strip_level_dbg"),
+        "fastbuild": attr.label(default = "//rust/settings:strip_level_fastbuild"),
+        "opt": attr.label(default = "//rust/settings:strip_level_opt"),
+    },
+)

rust/private/toolchain.bzl

@@ -8,12 +8,15 @@ load("@rules_cc//cc/common:cc_common.bzl", "cc_common")
 load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 load("//rust/platform:triple.bzl", "triple")
 load("//rust/private:common.bzl", "rust_common")
+load("//rust/private:debug_info.bzl", "RustDebugInfoInfo")
 load("//rust/private:lto.bzl", "RustLtoInfo")
+load("//rust/private:opt_level.bzl", "RustOptLevelInfo")
 load(
     "//rust/private:rust_allocator_libraries.bzl",
     "make_libstd_and_allocator_ccinfo",
 )
 load("//rust/private:semver.bzl", "semver")
+load("//rust/private:strip_level.bzl", "RustStripLevelInfo")
 load(
     "//rust/private:utils.bzl",
     "deduplicate",
@@ -393,16 +396,18 @@ def _rust_toolchain_impl(ctx):
     Returns:
         list: A list containing the target's toolchain Provider info
     """
+    effective_opt_levels = dict(ctx.attr._opt_level[RustOptLevelInfo].levels)
+    effective_opt_levels.update(ctx.attr.opt_level)
+
+    effective_debug_info = dict(ctx.attr._debug_info[RustDebugInfoInfo].levels)
+    effective_debug_info.update(ctx.attr.debug_info)
+
+    effective_strip_level = dict(ctx.attr._strip_level[RustStripLevelInfo].levels)
+    effective_strip_level.update(ctx.attr.strip_level)
+
     compilation_mode_opts = {}
-    for k, opt_level in ctx.attr.opt_level.items():
-        if not k in ctx.attr.debug_info:
-            fail("Compilation mode {} is not defined in debug_info but is defined opt_level".format(k))
-        if not k in ctx.attr.strip_level:
-            fail("Compilation mode {} is not defined in strip_level but is defined opt_level".format(k))
-        compilation_mode_opts[k] = struct(debug_info = ctx.attr.debug_info[k], opt_level = opt_level, strip_level = ctx.attr.strip_level[k])
-    for k in ctx.attr.debug_info.keys():
-        if not k in ctx.attr.opt_level:
-            fail("Compilation mode {} is not defined in opt_level but is defined debug_info".format(k))
+    for k, opt_level in effective_opt_levels.items():
+        compilation_mode_opts[k] = struct(debug_info = effective_debug_info[k], opt_level = opt_level, strip_level = effective_strip_level[k])
 
     rename_first_party_crates = ctx.attr._rename_first_party_crates[BuildSettingInfo].value
     third_party_dir = ctx.attr._third_party_dir[BuildSettingInfo].value
@@ -693,12 +698,13 @@ rust_toolchain = rule(
             cfg = "exec",
         ),
         "debug_info": attr.string_dict(
-            doc = "Rustc debug info levels per opt level",
-            default = {
-                "dbg": "2",
-                "fastbuild": "0",
-                "opt": "0",
-            },
+            doc = "Per-toolchain debug-info overrides per compilation mode. Any mode set here takes precedence over the global `//rust/settings:debug_info_*` flags. Omit a mode (or leave empty) to use the global flag value.",
+            default = {},
+        ),
+        "_debug_info": attr.label(
+            default = Label("//rust/settings:debug_info"),
+            providers = [RustDebugInfoInfo],
+            doc = "Global debug-info defaults, read from the `//rust/settings:debug_info_*` flags.",
         ),
         "default_edition": attr.string(
             doc = (
@@ -796,12 +802,13 @@ rust_toolchain = rule(
             doc = "Label to an LTO setting whether which can enable custom LTO settings",
         ),
         "opt_level": attr.string_dict(
-            doc = "Rustc optimization levels.",
-            default = {
-                "dbg": "0",
-                "fastbuild": "0",
-                "opt": "3",
-            },
+            doc = "Per-toolchain opt-level overrides per compilation mode. Any mode set here takes precedence over the global `//rust/settings:opt_level_*` flags. Omit a mode (or leave empty) to use the global flag value.",
+            default = {},
+        ),
+        "_opt_level": attr.label(
+            default = Label("//rust/settings:opt_level"),
+            providers = [RustOptLevelInfo],
+            doc = "Global opt-level defaults, read from the `//rust/settings:opt_level_*` flags.",
         ),
         "per_crate_rustc_flags": attr.string_list(
             doc = "Extra flags to pass to rustc in non-exec configuration",
@@ -857,15 +864,13 @@ rust_toolchain = rule(
             mandatory = True,
         ),
         "strip_level": attr.string_dict(
-            doc = (
-                "Rustc strip levels. For all potential options, see " +
-                "https://doc.rust-lang.org/rustc/codegen-options/index.html#strip"
-            ),
-            default = {
-                "dbg": "none",
-                "fastbuild": "none",
-                "opt": "debuginfo",
-            },
+            doc = "Per-toolchain strip-level overrides per compilation mode. Any mode set here takes precedence over the global `//rust/settings:strip_level_*` flags. Omit a mode (or leave empty) to use the global flag value.",
+            default = {},
+        ),
+        "_strip_level": attr.label(
+            default = Label("//rust/settings:strip_level"),
+            providers = [RustStripLevelInfo],
+            doc = "Global strip-level defaults, read from the `//rust/settings:strip_level_*` flags.",
         ),
         "target_json": attr.string(
             doc = ("Override the target_triple with a custom target specification. " +

rust/settings/BUILD.bazel

@@ -10,6 +10,7 @@ load(
     "clippy_toml",
     "codegen_units",
     "collect_cfgs",
+    "debug_info",
     "default_allocator_library",
     "error_format",
     "experimental_compile_rustdoc_tests",
@@ -31,11 +32,13 @@ load(
     "incompatible_do_not_include_transitive_data_in_compile_inputs",
     "lto",
     "no_std",
+    "opt_level",
     "pipelined_compilation",
     "rename_first_party_crates",
     "require_explicit_unstable_features",
     "rustc_output_diagnostics",
     "rustfmt_toml",
+    "strip_level",
     "third_party_dir",
     "toolchain_generated_sysroot",
     "toolchain_linker_preference",
@@ -117,10 +120,14 @@ incompatible_do_not_include_data_in_compile_data()
 
 incompatible_do_not_include_transitive_data_in_compile_inputs()
 
+debug_info()
+
 lto()
 
 no_std()
 
+opt_level()
+
 pipelined_compilation()
 
 rename_first_party_crates()
@@ -131,6 +138,8 @@ rustc_output_diagnostics()
 
 rustfmt_toml()
 
+strip_level()
+
 third_party_dir()
 
 toolchain_generated_sysroot()