fix: address gemini-code-assist nits on #4236

Two follow-ups from gemini's second review pass on #4236:

  * `setattr -unset src *` in `write_state_hash` only strips src
    attrs from objects in the *current* module.  `write_state_hash`
    runs before `hierarchy -check -top` in synth_canonicalize.tcl,
    so the post-frontend design has many separate modules whose
    src attrs (= file:line metadata) survive the strip and end up
    in the hashed RTLIL, breaking path-independence between the
    bazel sandbox and the classic-make build.  Use `*/*` which
    selects across all modules.

  * The genMetrics.py regex for the new hash was anchored to a
    bare `^`, while other extractors in the same file allow optional
    leading whitespace.  Add `\s*` after `^` so the extraction is
    robust to any log wrapper that inserts indentation.

Signed-off-by: Øyvind Harboe <oyvind@ascenium.com>
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

Author: oharboe

flow/scripts/synth_preamble.tcl

@@ -19,7 +19,14 @@ erase_non_stage_variables synth
 # the canonical-RTLIL write.
 proc write_state_hash { metric } {
   design -push
-  setattr -unset src *
+  # `*/*` strips src attrs across objects in *all* modules.  Bare `*`
+  # only targets the current module's objects, which is fine after
+  # `hierarchy -check -top` collapses things to one design, but
+  # `write_state_hash` is called before `hierarchy` here, so the
+  # post-frontend state may have many separate modules whose src
+  # attrs would otherwise survive into the hashed RTLIL and break
+  # path-independence.
+  setattr -unset src */*
   setattr -mod -unset src *
   set tmp $::env(OBJECTS_DIR)/.${metric}.tmp.rtlil
   write_rtlil $tmp

flow/util/genMetrics.py

@@ -280,7 +280,7 @@ def extract_metrics(
     extractTagFromFile(
         "synth__post_read_sources__hash",
         metrics_dict,
-        r"^synth__post_read_sources__hash:\s+([0-9a-f]{40})\s*$",
+        r"^\s*synth__post_read_sources__hash:\s+([0-9a-f]{40})\s*$",
         logPath + "/1_1_yosys_canonicalize.log",
         t=str,
         required=False,