Mix checklocks and atomic analyzers.

This change makes the checklocks analyzer considerable more powerful, adding:
* The ability to traverse complex structures, e.g. to have multiple nested
  fields as part of the annotation.
* The ability to resolve simple anonymous functions and closures, and perform
  lock analysis across these invocations. This does not apply to closures that
  are passed elsewhere, since it is not possible to know the context in which
  they might be invoked.
* The ability to annotate return values in addition to receivers and other
  parameters, with the same complex structures noted above.
* Ignoring locking semantics for "fresh" objects, i.e. objects that are
  allocated in the local frame (typically a new-style function).
* Sanity checking of locking state across block transitions and returns, to
  ensure that no unexpected locks are held.

Note that initially, most of these findings are excluded by a comprehensive
nogo.yaml. The findings that are included are fundamental lock violations.
The changes here should be relatively low risk, minor refactorings to either
include necessary annotations to simplify the code structure (in general
removing closures in favor of methods) so that the analyzer can be easily
track the lock state.

This change additional includes two changes to nogo itself:
* Sanity checking of all types to ensure that the binary and ast-derived
  types have a consistent objectpath, to prevent the bug above from occurring
  silently (and causing much confusion). This also requires a trick in
  order to ensure that serialized facts are consumable downstream. This can
  be removed with https://go-review.googlesource.com/c/tools/+/331789 merged.
* A minor refactoring to isolation the objdump settings in its own package.
  This was originally used to implement the sanity check above, but this
  information is now being passed another way. The minor refactor is preserved
  however, since it cleans up the code slightly and is minimal risk.

PiperOrigin-RevId: 382613300

1 files changed, 26 insertions, 13 deletions

diff --git a/tools/nogo/defs.bzl b/tools/nogo/defs.bzl
index ddf5816a6..80182ff6c 100644
--- a/tools/nogo/defs.bzl
+++ b/tools/nogo/defs.bzl
@@ -198,6 +198,22 @@ NogoInfo = provider(
     },
 )
 
+def _select_objfile(files):
+    """Returns (.a file, .x file, is_archive).
+
+    If no .a file is available, then the first .x file will be returned
+    instead, and vice versa. If neither are available, then the first provided
+    file will be returned."""
+    a_files = [f for f in files if f.path.endswith(".a")]
+    x_files = [f for f in files if f.path.endswith(".x")]
+    if not len(x_files) and not len(a_files):
+        return (files[0], files[0], False)
+    if not len(x_files):
+        x_files = a_files
+    if not len(a_files):
+        a_files = x_files
+    return a_files[0], x_files[0], True
+
 def _nogo_aspect_impl(target, ctx):
     # If this is a nogo rule itself (and not the shadow of a go_library or
     # go_binary rule created by such a rule), then we simply return nothing.
@@ -232,20 +248,14 @@ def _nogo_aspect_impl(target, ctx):
             deps = deps + info.deps
 
     # Start with all target files and srcs as input.
-    inputs = target.files.to_list() + srcs
+    binaries = target.files.to_list()
+    inputs = binaries + srcs
 
     # Generate a shell script that dumps the binary. Annoyingly, this seems
     # necessary as the context in which a run_shell command runs does not seem
     # to cleanly allow us redirect stdout to the actual output file. Perhaps
     # I'm missing something here, but the intermediate script does work.
-    binaries = target.files.to_list()
-    objfiles = [f for f in binaries if f.path.endswith(".a")]
-    if len(objfiles) > 0:
-        # Prefer the .a files for go_library targets.
-        target_objfile = objfiles[0]
-    else:
-        # Use the raw binary for go_binary and go_test targets.
-        target_objfile = binaries[0]
+    target_objfile, target_xfile, has_objfile = _select_objfile(binaries)
     inputs.append(target_objfile)
 
     # Extract the importpath for this package.
@@ -274,10 +284,8 @@ def _nogo_aspect_impl(target, ctx):
         # Configure where to find the binary & fact files. Note that this will
         # use .x and .a regardless of whether this is a go_binary rule, since
         # these dependencies must be go_library rules.
-        x_files = [f.path for f in info.binaries if f.path.endswith(".x")]
-        if not len(x_files):
-            x_files = [f.path for f in info.binaries if f.path.endswith(".a")]
-        import_map[info.importpath] = x_files[0]
+        _, x_file, _ = _select_objfile(info.binaries)
+        import_map[info.importpath] = x_file.path
         fact_map[info.importpath] = info.facts.path
 
         # Collect all findings; duplicates are resolved at the end.
@@ -287,6 +295,11 @@ def _nogo_aspect_impl(target, ctx):
         inputs.append(info.facts)
         inputs += info.binaries
 
+    # Add the module itself, for the type sanity check. This applies only to
+    # the libraries, and not binaries or tests.
+    if has_objfile:
+        import_map[importpath] = target_xfile.path
+
     # Add the standard library facts.
     stdlib_info = ctx.attr._nogo_stdlib[NogoStdlibInfo]
     stdlib_facts = stdlib_info.facts