refactor: Introduce a virtual manifest

Move the workspace configuration to a virtual manifest. This
reorganization makes a more clear separation between package contents
and support files that don't get distributed. It will also make it
easier to merge this repository with `compiler-builtins` which is
planned (builtins had a similar update done in [1]).

LICENSE.txt and README.md are symlinkedinto the new directory to ensure
they get included in the package.

[1]: https://github.com/rust-lang/compiler-builtins/pull/702

library/compiler-builtins/libm/Cargo.toml

@@ -0,0 +1,37 @@
+[workspace]
+resolver = "2"
+members = [
+  "libm",
+  "crates/libm-macros",
+  "crates/libm-test",
+  "crates/musl-math-sys",
+  "crates/util",
+]
+default-members = [
+  "libm",
+  "crates/libm-macros",
+  "crates/libm-test"
+]
+exclude = [
+  # Requires `panic = abort` so can't be a member of the workspace
+  "crates/compiler-builtins-smoke-test",
+]
+
+# The default release profile is unchanged.
+
+# Release mode with debug assertions
+[profile.release-checked]
+inherits = "release"
+debug-assertions = true
+overflow-checks = true
+
+# Release with maximum optimizations, which is very slow to build. This is also
+# what is needed to check `no-panic`.
+[profile.release-opt]
+inherits = "release"
+codegen-units = 1
+lto = "fat"
+
+[profile.bench]
+# Required for iai-callgrind
+debug = true

library/compiler-builtins/libm/ci/ci-util.py

@@ -25,7 +25,7 @@ USAGE = cleandoc(
     COMMAND:
         generate-matrix
             Calculate a matrix of which functions had source change, print that as
-             a JSON object.
+            a JSON object.
 
         locate-baseline [--download] [--extract]
             Locate the most recent benchmark baseline available in CI and, if flags

library/compiler-builtins/libm/etc/update-api-list.py

@@ -18,10 +18,10 @@ from typing import Any, Callable, TypeAlias
 
 SELF_PATH = Path(__file__)
 ETC_DIR = SELF_PATH.parent
-LIBM_DIR = ETC_DIR.parent.joinpath("libm")
+ROOT_DIR = ETC_DIR.parent
 
 # These files do not trigger a retest.
-IGNORED_SOURCES = ["src/libm_helper.rs", "src/math/support/float_traits.rs"]
+IGNORED_SOURCES = ["libm/src/libm_helper.rs", "libm/src/math/support/float_traits.rs"]
 
 IndexTy: TypeAlias = dict[str, dict[str, Any]]
 """Type of the `index` item in rustdoc's JSON output"""
@@ -66,7 +66,7 @@ class Crate:
         j = sp.check_output(
             [
                 "rustdoc",
-                "src/lib.rs",
+                "libm/src/lib.rs",
                 "--edition=2021",
                 "--document-private-items",
                 "--output-format=json",
@@ -75,7 +75,7 @@ class Crate:
                 "-Zunstable-options",
                 "-o-",
             ],
-            cwd=LIBM_DIR,
+            cwd=ROOT_DIR,
             text=True,
         )
         j = json.loads(j)
@@ -94,7 +94,9 @@ class Crate:
         # Collect a list of source IDs for reexported items in `lib.rs` or `mod math`.
         use = (i for i in public if "use" in i["inner"])
         use = (
-            i for i in use if i["span"]["filename"] in ["src/math/mod.rs", "src/lib.rs"]
+            i
+            for i in use
+            if i["span"]["filename"] in ["libm/src/math/mod.rs", "libm/src/lib.rs"]
         )
         reexported_ids = [item["inner"]["use"]["id"] for item in use]
 
@@ -121,8 +123,8 @@ class Crate:
 
         # A lot of the `arch` module is often configured out so doesn't show up in docs. Use
         # string matching as a fallback.
-        for fname in glob("src/math/arch/**.rs", root_dir=LIBM_DIR):
-            contents = (LIBM_DIR.joinpath(fname)).read_text()
+        for fname in glob("libm/src/math/arch/**.rs", root_dir=ROOT_DIR):
+            contents = (ROOT_DIR.joinpath(fname)).read_text()
 
             for name in self.public_functions:
                 if f"fn {name}" in contents:
@@ -188,10 +190,10 @@ class Crate:
         include all public API.
         """
 
-        flist = sp.check_output(["git", "ls-files"], cwd=LIBM_DIR, text=True)
+        flist = sp.check_output(["git", "ls-files"], cwd=ROOT_DIR, text=True)
 
         for path in flist.splitlines():
-            fpath = LIBM_DIR.joinpath(path)
+            fpath = ROOT_DIR.joinpath(path)
             if fpath.is_dir() or fpath == SELF_PATH:
                 continue
 
@@ -229,7 +231,7 @@ class Crate:
         if len(not_found) == 0:
             return
 
-        relpath = fpath.relative_to(LIBM_DIR)
+        relpath = fpath.relative_to(ROOT_DIR)
         eprint(f"functions not found at {relpath}:{line_num}: {not_found}")
         exit(1)
 
@@ -244,7 +246,7 @@ def validate_delimited_block(
     """Identify blocks of code wrapped within `start` and `end`, collect their contents
     to a list of strings, and call `validate` for each of those lists.
     """
-    relpath = fpath.relative_to(LIBM_DIR)
+    relpath = fpath.relative_to(ROOT_DIR)
     block_lines = []
     block_start_line: None | int = None
     for line_num, line in enumerate(lines):
@@ -274,7 +276,7 @@ def validate_delimited_block(
 
 def ensure_sorted(fpath: Path, block_start_line: int, lines: list[str]) -> None:
     """Ensure that a list of lines is sorted, otherwise print a diff and exit."""
-    relpath = fpath.relative_to(LIBM_DIR)
+    relpath = fpath.relative_to(ROOT_DIR)
     diff_and_exit(
         "\n".join(lines),
         "\n".join(sorted(lines)),

library/compiler-builtins/libm/libm/Cargo.toml

@@ -10,7 +10,6 @@ readme = "README.md"
 repository = "https://github.com/rust-lang/libm"
 version = "0.2.11"
 edition = "2021"
-exclude = ["/ci/", "/.github/workflows/"]
 rust-version = "1.63"
 
 [features]
@@ -40,24 +39,6 @@ unstable-float = []
 # hard float operations.
 force-soft-floats = []
 
-[workspace]
-resolver = "2"
-members = [
-  "crates/libm-macros",
-  "crates/libm-test",
-  "crates/musl-math-sys",
-  "crates/util",
-]
-default-members = [
-  ".",
-  "crates/libm-macros",
-  "crates/libm-test",
-]
-exclude = [
-  # Requires `panic = abort` so can't be a member of the workspace
-  "crates/compiler-builtins-smoke-test",
-]
-
 [dev-dependencies]
 no-panic = "0.1.35"
 
@@ -66,22 +47,3 @@ unexpected_cfgs = { level = "warn", check-cfg = [
   # compiler-builtins sets this feature, but we use it in `libm`
   'cfg(feature, values("compiler-builtins"))',
 ] }
-
-# The default release profile is unchanged.
-
-# Release mode with debug assertions
-[profile.release-checked]
-inherits = "release"
-debug-assertions = true
-overflow-checks = true
-
-# Release with maximum optimizations, which is very slow to build. This is also
-# what is needed to check `no-panic`.
-[profile.release-opt]
-inherits = "release"
-codegen-units = 1
-lto = "fat"
-
-[profile.bench]
-# Required for iai-callgrind
-debug = true

library/compiler-builtins/libm/libm/LICENSE.txt

@@ -0,0 +1 @@
+../LICENSE.txt

library/compiler-builtins/libm/libm/README.md

@@ -0,0 +1 @@
+../README.md