C initializers: designated + nested/brace-elided initializers (EPIC)

• Type: bug epic (miscompile — compiles clean, runs wrong). Track C (cparser init lowering).
• Priority: HIGH — silent wrong data, biggest c-testsuite failure cluster (9 tests).
• Found: 2026-07-06, c-testsuite conformance run (tools/run_c_conformance.sh), baseline 178/220.
• Decomposed 2026-07-06 (too big for one landing; three code sites + a recursive rework). Now an epic that completes when its three slices land — do them in order:
  1. [[bug-c-init-struct-designators]] — DONE 2026-07-06 (098e5b94): .field = cursor, local + global; 00048/00049 pass.
  2. [[bug-c-init-array-designators]] — DONE 2026-07-06 (c0abec31): [i] = cursor + [] size inference; 00092/00147/00148 pass.
  3. [[bug-c-init-brace-elision-nested]] — recursive elision walker (hardest, subsumes the two cursors). The prio (90) propagates to all three, so they float to the top of Track C.

Failing tests (library_candidates/c-testsuite/tests/single-exec)

• 00048 struct S s = { .b = 2, .a = 1 }; — designated struct init, exit 1 (s.a != 1)
• 00049 struct S s = { .p = &x, .a = 1 }; — designator + address-of global
• 00050 anonymous union inside braced init {1, 2, 3, {4, 5}} — exit 3
• 00091 S a[1] = {{1, {2, 3}}}; nested braces array-of-struct — exit 1
• 00092 int a[] = {5, [2] = 2, 3}; array designator + size inference — exit 1
• 00147 int arr[3] = {[2] = 2, [0] = 0, [1] = 1}; out-of-order — exit 2
• 00148 struct S arr[2] = {[1] = {3, 4}, [0] = {1, 2}}; — exit 1
• 00205 brace-ELIDED flat init of PT cases[] (J interpreter snippet) — wrong values AND wrong element count (output 315 lines vs 72 expected → sizeof(cases) wrong too)
• 00216 sundry init battery (also needs compound literals — see feature-c-compound-literals)

Symptom

Designators (.field =, [idx] =) apparently parsed but values land in wrong slots (declaration-order assignment, designator ignored?). Brace elision (C99 6.7.8p20: { {1}, 2 } and fully flat lists) mis-distributes values and mis-counts elements for [] size inference.

Fix site

cparser.inc global/local braced-init path (same region as the v185 block-scope char buf[]="lit" fix). Needs: designator cursor (current field/index that designators reset), brace-elision descent, size inference = max index + 1.

Gate

Remove the 9 lines from test/c-conformance/pxx.skip; tools/run_c_conformance.sh green.

Log

• 2026-07-08 — resolved, commit e0f9f5e4.