Attempt to download MSVC from GitHub Actions

.github/workflows/build-qt.yml

@@ -249,6 +249,7 @@ jobs:
           version: '5.15.2'
           host: 'windows'
           target: 'desktop'
+          dir: '${{github.workspace}}/qt/'
           arch: 'win64_msvc2015_64'
           archives: 'qtbase'
 
@@ -272,17 +273,121 @@ jobs:
               // default directories to be searched for libraries when linking
               lib-dirs = [
                   "$HOME/ldc2-1.33.0-windows-x64/lib",
+                  "${{github.workspace}}/msvc/VC/Tools/MSVC/14.38.33130/lib/x64",
+                  "$Qt5_DIR/lib",
               ];
           };
           EOF
           curl -LO https://github.com/ldc-developers/ldc/releases/download/v1.33.0/ldc2-1.33.0-windows-x64.7z
           7z x ./ldc2-1.33.0-windows-x64.7z -o$HOME
 
-      - name: Set-up Qt for cross-compilation
+      - name: Set-up LDC2 for cross-compilation
         run: |
-          cp -r $Qt5_DIR/lib/* $HOME/ldc2-1.33.0-windows-x64/lib
           ln $HOME/ldc2-1.33.0-windows-x64/lib/mingw/msvcrt.lib $HOME/ldc2-1.33.0-windows-x64/lib/mingw/MSVCRT.lib
           ln $HOME/ldc2-1.33.0-windows-x64/lib/mingw/oldnames.lib $HOME/ldc2-1.33.0-windows-x64/lib/mingw/OLDNAMES.lib
+          python3 << EOF
+          # SOURCE: https://gist.github.com/mmozeiko/7f3162ec2988e81e56d5c4e22cde9977
+          # Edits to make it non-interactive and smaller.
+            
+          import io
+          import os
+          import sys
+          import json
+          import shutil
+          import hashlib
+          import zipfile
+          import tempfile
+          import argparse
+          import subprocess
+          import urllib.request
+          from pathlib import Path
+          
+          OUTPUT = Path("${{github.workspace}}/msvc")  # output folder
+          
+          # other architectures may work or may not - not really tested
+          HOST = "x64"  # or x86
+          TARGET = "x64"  # or x86, arm, arm64
+          
+          MANIFEST_URL = "https://aka.ms/vs/17/release/channel"
+          
+          def download(url):
+            with urllib.request.urlopen(url) as res:
+              return res.read()
+          
+          
+          def download_progress(url, check, name, f):
+            data = io.BytesIO()
+            with urllib.request.urlopen(url) as res:
+              total = int(res.headers["Content-Length"])
+              size = 0
+              while True:
+                block = res.read(1 << 20)
+                if not block:
+                  break
+                f.write(block)
+                data.write(block)
+                size += len(block)
+                perc = size * 100 // total
+                print(f"\r{name} ... {perc}%", end="")
+            print()
+            data = data.getvalue()
+            digest = hashlib.sha256(data).hexdigest()
+            if check.lower() != digest:
+              exit(f"Hash mismatch for f{pkg}")
+            return data
+          
+          
+          def first(items, cond):
+            return next(item for item in items if cond(item))
+          
+          
+          ### get main manifest
+            
+          manifest = json.loads(download(MANIFEST_URL))
+          
+          ### download VS manifest
+          
+          vs = first(manifest["channelItems"], lambda x: x["id"] == "Microsoft.VisualStudio.Manifests.VisualStudio")
+          payload = vs["payloads"][0]["url"]
+          
+          vsmanifest = json.loads(download(payload))
+          
+          ### find MSVC & WinSDK versions
+          
+          packages = {}
+          for p in vsmanifest["packages"]:
+            packages.setdefault(p["id"].lower(), []).append(p)
+            
+            msvc = {}
+            sdk = {}
+          
+          for pid, p in packages.items():
+            if pid.startswith("Microsoft.VisualStudio.Component.VC.".lower()) and pid.endswith(".x86.x64".lower()):
+              pver = ".".join(pid.split(".")[4:6])
+              if pver[0].isnumeric():
+                msvc[pver] = pid
+            
+          msvc_ver = "14.38.33130"
+          msvc_pid = msvc[msvc_ver]
+          msvc_ver = ".".join(msvc_pid.split(".")[4:-2])
+          
+          OUTPUT.mkdir(exist_ok=True)
+          total_download = 0
+          
+          pkg = f"microsoft.vc.{msvc_ver}.crt.{TARGET}.store.base"
+          
+          p = first(packages[pkg], lambda p: p.get("language") in (None, "en-US"))
+          for payload in p["payloads"]:
+            with tempfile.TemporaryFile() as f:
+              data = download_progress(payload["url"], payload["sha256"], pkg, f)
+              total_download += len(data)
+              with zipfile.ZipFile(f) as z:
+                for name in z.namelist():
+                  if name.startswith("Contents/"):
+                    out = OUTPUT / Path(name).relative_to("Contents")
+                    out.parent.mkdir(parents=True, exist_ok=True)
+                    out.write_bytes(z.read(name))
+          EOF
 
       - name: Write version file
         run: echo 'module version_string; enum versionStr = "Sideloader automated build, branch ${{ github.ref_name }}, commit ${{ github.sha }}";' > source/version_string.d