C parser/main

.githooks/pre-commit

@@ -0,0 +1,20 @@
+#!/usr/bin/env sh
+set -eu
+
+branch=$(git branch --show-current)
+
+if [ "$branch" != "main" ]; then
+  exit 0
+fi
+
+changed=$(git diff --cached --name-only)
+
+if printf '%s\n' "$changed" | grep -Eq '^(\.github/workflows/c-parser-main-guard\.yml|\.githooks/|docs/c_parser/|c_parser/|tests/(c_parser|parser/c|data/c)/|semantics/c2ir\.py)'; then
+  cat >&2 <<'MSG'
+Blocked: C parser files are staged on main.
+
+Work on c-parser/main or a c-parser/* branch instead. The final main merge
+requires the C parser readiness checklist to be complete and explicit approval.
+MSG
+  exit 1
+fi

.githooks/pre-merge-commit

@@ -0,0 +1,24 @@
+#!/usr/bin/env sh
+set -eu
+
+branch=$(git branch --show-current)
+
+if [ "$branch" != "main" ]; then
+  exit 0
+fi
+
+if ! git rev-parse -q --verify MERGE_HEAD >/dev/null; then
+  exit 0
+fi
+
+merge_head=$(git rev-parse MERGE_HEAD)
+
+if git branch --all --contains "$merge_head" | grep -Eq '(^|[[:space:]])(remotes/origin/)?c-parser/'; then
+  cat >&2 <<'MSG'
+Blocked: attempting to merge a c-parser/* branch into main.
+
+Merge C parser work into c-parser/main only. The final main merge requires the
+C parser readiness checklist to be complete and explicit approval.
+MSG
+  exit 1
+fi

.githooks/pre-push

@@ -0,0 +1,42 @@
+#!/usr/bin/env sh
+set -eu
+
+current_branch=$(git branch --show-current)
+
+while read -r local_ref local_sha remote_ref remote_sha
+do
+  case "$remote_ref" in
+    refs/heads/main)
+      ;;
+    *)
+      continue
+      ;;
+  esac
+
+  if printf '%s\n' "$current_branch" | grep -Eq '^c-parser/'; then
+    cat >&2 <<'MSG'
+Blocked: refusing to push a c-parser/* branch to remote main.
+
+Push C parser work to c-parser/main or another c-parser/* branch only.
+MSG
+    exit 1
+  fi
+
+  if [ "$remote_sha" = "0000000000000000000000000000000000000000" ]; then
+    range="$local_sha"
+  else
+    range="$remote_sha..$local_sha"
+  fi
+
+  changed=$(git diff --name-only "$range")
+
+  if printf '%s\n' "$changed" | grep -Eq '^(\.github/workflows/c-parser-main-guard\.yml|\.githooks/|docs/c_parser/|c_parser/|tests/(c_parser|parser/c|data/c)/|semantics/c2ir\.py)'; then
+    cat >&2 <<'MSG'
+Blocked: refusing to push C parser files to remote main.
+
+Push C parser work to c-parser/main. The final main merge requires the C parser
+readiness checklist to be complete and explicit approval.
+MSG
+    exit 1
+  fi
+done

.github/workflows/c-parser-main-guard.yml

@@ -0,0 +1,59 @@
+name: C Parser Main Guard
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, labeled, unlabeled]
+
+jobs:
+  c-parser-main-guard:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Reject premature C parser work targeting main
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+          HEAD_REF: ${{ github.event.pull_request.head.ref }}
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+          PR_LABELS: ${{ join(github.event.pull_request.labels.*.name, ',') }}
+        run: |
+          set -euo pipefail
+
+          if [ "$BASE_REF" != "main" ]; then
+            echo "PR does not target main; C parser main guard does not apply."
+            exit 0
+          fi
+
+          ALLOW_LABEL="c-parser-ready-for-main"
+
+          if echo ",${PR_LABELS}," | grep -Fq ",${ALLOW_LABEL},"; then
+            echo "${ALLOW_LABEL} label present; allowing C parser merge candidate."
+            exit 0
+          fi
+
+          CHANGED_FILES=$(git diff --name-only "$BASE_SHA" "$HEAD_SHA")
+
+          echo "Base branch: $BASE_REF"
+          echo "Head branch: $HEAD_REF"
+          echo "Changed files:"
+          echo "$CHANGED_FILES"
+
+          C_PARSER_PATH_PATTERN='^(\.github/workflows/c-parser-main-guard\.yml|\.githooks/|docs/c_parser/|c_parser/|tests/(c_parser|parser/c|data/c)/|semantics/c2ir\.py)'
+
+          if echo "$HEAD_REF" | grep -Eq '^c-parser/'; then
+            echo "C parser branches must not target main before the C parser is ready."
+            echo "Target c-parser/main instead, or add ${ALLOW_LABEL} only for the final approved merge."
+            exit 1
+          fi
+
+          if echo "$CHANGED_FILES" | grep -Eq "$C_PARSER_PATH_PATTERN"; then
+            echo "C parser files changed in a PR targeting main."
+            echo "Target c-parser/main instead, or add ${ALLOW_LABEL} only for the final approved merge."
+            exit 1
+          fi
+
+          echo "No C parser branch or C parser paths detected in a PR targeting main."

.github/workflows/parser-reference-guard.yml

@@ -46,7 +46,7 @@ jobs:
           fi
 
           DOC_CHANGED=false
-          if echo "$CHANGED_FILES" | grep -Fxq "parser_implementation_reference.md"; then
+          if echo "$CHANGED_FILES" | grep -Fxq "docs/fortran/parser_implementation_reference.md"; then
             DOC_CHANGED=true
           fi
 
@@ -60,12 +60,12 @@ jobs:
           fi
 
           if [ "$DOC_CHANGED" = true ]; then
-            echo "parser_implementation_reference.md changed."
+            echo "docs/fortran/parser_implementation_reference.md changed."
             exit 0
           fi
 
           if echo "$CHANGED_FILES" | grep -Eq "^(fortran_parser/|tests/parser/|tests/data/fortran/)"; then
-            echo "Parser-related files changed without updating parser_implementation_reference.md."
+            echo "Parser-related files changed without updating docs/fortran/parser_implementation_reference.md."
             exit 1
           fi
 

AGENTS.md

@@ -6,6 +6,8 @@ Ignore:
 - *.f90
 - *.f95
 - *.for
+- *.c
+- *.h
 - *.json
 
 Do not spend context window or analysis on those files unless explicitly requested.

CONTRIBUTING.md

@@ -7,7 +7,7 @@
 
 ### Parser reference guard
 
-This repo includes a CI guard that may require updating `parser_implementation_reference.md` when parser-related files change.
+This repo includes a CI guard that may require updating `docs/fortran/parser_implementation_reference.md` when parser-related files change.
 
-- **Default behavior**: if you change `fortran_parser/` or `tests/data/fortran/`, update `parser_implementation_reference.md` when the change affects the documented feature inventory or behavior.
+- **Default behavior**: if you change `fortran_parser/` or `tests/data/fortran/`, update `docs/fortran/parser_implementation_reference.md` when the change affects the documented feature inventory or behavior.
 - **Bypass (use sparingly)**: add the PR label `ignore-parser-reference-guard` to skip that guard for changes that do not meaningfully affect the reference.