Migrate CI to Github Actions (#1884)

Changes the CI system from Jenkins to Github Actions (GHA) like we did for OoT

This is an adaptation of the Jenkinsfile we have and the solution made by @Dragorn421 for OoT

Relevant OoT PRs:
- https://github.com/zeldaret/oot/pull/2740
- https://github.com/zeldaret/oot/pull/2742
- https://github.com/zeldaret/oot/pull/2754

New features include:
- Not needing to selfhost a runner
  - Required private stuff for building is hosted on a private repo
- Building multiple versions in parallel
  - Our old jenkinsfile wasn't building `n64-jp-1.1`. Even if it doesn't match right now, I think it is important checking a PR doesn't completely break it.
- Run bss fixer in CI
- Upload mapfiles as build artifacts

This specific approach to handle GHA for decomp projects was adapted from the one used by the GC/Wii community. It is documented here https://github.com/encounter/dtk-template/blob/main/docs/github_actions.md There's a writeup about this adaptation for N64 projects [here](https://github.com/AngheloAlf/drmario64/pull/19).

2 files changed, 122 insertions, 0 deletions

diff --git a/.github/scripts/apply_fix_bss_patches.py b/.github/scripts/apply_fix_bss_patches.py
new file mode 100644
index 000000000..06c79fe52
--- /dev/null
+++ b/.github/scripts/apply_fix_bss_patches.py
@@ -0,0 +1,112 @@
+# SPDX-FileCopyrightText: © 2026 ZeldaRET
+# SPDX-License-Identifier: CC0-1.0
+
+from pathlib import Path
+import re
+import subprocess
+
+
+def get_increment_block_numbers(p: Path, version: str):
+    increment_block_numbers: list[int] = []
+    is_in_pragma = False
+    n_fake_structs = None
+    for l in p.read_text().splitlines():
+        if l.startswith("#pragma increment_block_number"):
+            is_in_pragma = True
+            n_fake_structs = 0
+        if is_in_pragma:
+            m = next(re.finditer(rf"{version}:(\d+)", l), None)
+            if m is not None:
+                n_fake_structs = int(m.group(1))
+        if is_in_pragma and not l.endswith("\\"):
+            is_in_pragma = False
+            assert n_fake_structs is not None
+            increment_block_numbers.append(n_fake_structs)
+            n_fake_structs = None
+    return increment_block_numbers
+
+
+# Formats #pragma increment_block_number as a list of lines
+def format_pragma(amounts: dict[str, int], max_line_length: int) -> list[str]:
+    lines = []
+    pragma_start = "#pragma increment_block_number "
+    current_line = pragma_start + '"'
+    first = True
+    for version, amount in sorted(amounts.items()):
+        part = f"{version}:{amount}"
+        if len(current_line) + len(" ") + len(part) + len('" \\') > max_line_length:
+            lines.append(current_line + '" ')
+            current_line = " " * len(pragma_start) + '"'
+            first = True
+        if not first:
+            current_line += " "
+        current_line += part
+        first = False
+    lines.append(current_line + '"\n')
+
+    if len(lines) >= 2:
+        # add and align vertically all continuation \ characters
+        n_align = max(map(len, lines[:-1]))
+        for i in range(len(lines) - 1):
+            lines[i] = f"{lines[i]:{n_align}}\\\n"
+
+    return lines
+
+
+def set_increment_block_numbers(
+    p: Path, increment_block_numbers_by_version: dict[str, list[int]]
+):
+    print(p, increment_block_numbers_by_version)
+    i_pragma = 0
+    is_in_pragma = False
+    pragma_lines = []
+    new_lines = []
+    for l in p.read_text().splitlines(keepends=True):
+        if l.startswith("#pragma increment_block_number"):
+            is_in_pragma = True
+        if not is_in_pragma:
+            new_lines.append(l)
+        if is_in_pragma:
+            pragma_lines.append(l.removesuffix("\\\n"))
+        if is_in_pragma and not l.endswith("\\\n"):
+            is_in_pragma = False
+            pragma_string = "".join(pragma_lines)
+            amounts: dict[str, int] = {}
+            for part in pragma_string.replace('"', "").split()[2:]:
+                version, amount_str = part.split(":")
+                amount = int(amount_str)
+                amounts[version] = amount
+            for (
+                version,
+                increment_block_numbers,
+            ) in increment_block_numbers_by_version.items():
+                amounts[version] = increment_block_numbers[i_pragma]
+            i_pragma += 1
+            column_limit = 120  # matches .clang-format's ColumnLimit
+            new_pragma_lines = format_pragma(amounts, column_limit)
+            new_lines.extend(new_pragma_lines)
+    p.write_text("".join(new_lines))
+
+
+increment_block_numbers_by_version_by_file: dict[Path, dict[str, list[int]]] = {}
+for p in Path(".").glob("fix_bss_*.patch"):
+    version = p.name.removeprefix("fix_bss_").removesuffix(".patch")
+    subprocess.check_call(["git", "apply", str(p)])
+    touched_files = subprocess.check_output(
+        "git diff --name-only".split(),
+        text=True,
+    ).splitlines()
+    for file in touched_files:
+        file_p = Path(file)
+        increment_block_numbers = get_increment_block_numbers(file_p, version)
+        increment_block_numbers_by_version_by_file.setdefault(file_p, {})[
+            version
+        ] = increment_block_numbers
+    subprocess.check_call("git checkout -- .".split())
+
+
+for (
+    file,
+    increment_block_numbers_by_version,
+) in increment_block_numbers_by_version_by_file.items():
+    set_increment_block_numbers(file, increment_block_numbers_by_version)
diff --git a/.github/scripts/generate_patch.sh b/.github/scripts/generate_patch.sh
new file mode 100755
index 000000000..04cc431b0
--- /dev/null
+++ b/.github/scripts/generate_patch.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PATCH=$(git diff | base64 -w 0)
+if [ -n "$PATCH" ]; then
+    echo 'Fixes were made for your PR. To apply these changes to your working directory, copy and run the following command:' >> $GITHUB_STEP_SUMMARY
+    echo '```' >> $GITHUB_STEP_SUMMARY
+    echo "echo -n $PATCH | base64 -d | git apply -" >> $GITHUB_STEP_SUMMARY
+    echo '```' >> $GITHUB_STEP_SUMMARY
+fi