msvc-kit 0.2.10

# Architecture Support


msvc-kit supports multiple CPU architectures for both host (build machine) and target (output binaries).

## Supported Architectures


| Architecture | As Host | As Target | Description |
|--------------|---------|-----------|-------------|
| `x64` | ✅ | ✅ | 64-bit x86 (AMD64) |
| `x86` | ✅ | ✅ | 32-bit x86 |
| `arm64` | ✅ | ✅ | ARM 64-bit |
| `arm` | ❌ | ✅ | ARM 32-bit (target only) |

## Host vs Target Architecture


- **Host Architecture**: The CPU architecture of your build machine
- **Target Architecture**: The CPU architecture of the compiled binaries

### Native Compilation


Build machine and output have the same architecture:

```bash
# On x64 machine, build x64 binaries

msvc-kit download --host-arch x64 --arch x64
```

### Cross Compilation


Build on one architecture for another:

```bash
# On x64 machine, build ARM64 binaries

msvc-kit download --host-arch x64 --arch arm64

# On x64 machine, build x86 (32-bit) binaries

msvc-kit download --host-arch x64 --arch x86
```

## Architecture Filtering


msvc-kit intelligently filters downloaded packages based on your specified architecture, significantly reducing download size and installation time.

### What Gets Downloaded


When you specify an architecture (e.g., `--arch x64`), msvc-kit downloads only:

| Package Type | Filtering Behavior |
|--------------|-------------------|
| **Tools** | Only matching host/target combination (e.g., `HostX64.TargetX64`) |
| **CRT Libraries** | Only matching architecture (e.g., `CRT.x64.Desktop`) |
| **MFC/ATL** | Only matching architecture (e.g., `MFC.x64`, `ATL.x64`) |
| **Headers** | Always included (architecture-neutral) |
| **Spectre Libraries** | Excluded by default (rarely needed) |

### What Gets Excluded


The following are automatically excluded to minimize download size:

- **Other architectures**: ARM64, x86, ARM packages when targeting x64
- **Spectre-mitigated libraries**: `.Spectre` suffix packages
- **Redundant packages**: Duplicate architecture variants

### Download Size Comparison


| Configuration | Approximate Size |
|--------------|------------------|
| All architectures (old behavior) | ~2.5 GB |
| Single architecture (x64) | ~300-500 MB |
| Minimal (tools only) | ~150-250 MB |

## Available Tools


### MSVC Compiler Tools


After downloading and setting up the environment, the following MSVC tools are available:

| Tool | Description |
|------|-------------|
| `cl.exe` | C/C++ compiler |
| `link.exe` | Linker |
| `lib.exe` | Static library manager |
| `ml64.exe` | MASM assembler (x64) |
| `ml.exe` | MASM assembler (x86) |
| `nmake.exe` | Microsoft make utility |

### Windows SDK Tools


The Windows SDK includes additional tools for development and deployment:

| Tool | Description |
|------|-------------|
| `rc.exe` | Resource compiler |
| `signtool.exe` | Code signing tool |
| `mt.exe` | Manifest tool |
| `makecat.exe` | Catalog creation tool |
| `makecert.exe` | Certificate creation tool |
| `certutil.exe` | Certificate utility |
| `mc.exe` | Message compiler |
| `midl.exe` | MIDL compiler |

### Using SDK Tools


After activating the environment, SDK tools are available in PATH:

```bash
# Activate environment

msvc-kit setup --script --shell powershell | Invoke-Expression

# Sign an executable

signtool sign /a /t http://timestamp.digicert.com myapp.exe

# Compile resources

rc /fo resources.res resources.rc

# Create manifest

mt -manifest app.manifest -outputresource:myapp.exe;1
```

### Tool Paths


The tools are located in:

```
# MSVC tools

{install_dir}/VC/Tools/MSVC/{version}/bin/Host{host_arch}/{target_arch}/

# SDK tools

{install_dir}/Windows Kits/10/bin/{sdk_version}/{arch}/
```

## Directory Structure


MSVC uses a specific directory structure for cross-compilation:

```
VC/Tools/MSVC/14.xx/bin/
├── Hostx64/
│   ├── x64/      # x64 host → x64 target (native)
│   ├── x86/      # x64 host → x86 target (cross)
│   └── arm64/    # x64 host → ARM64 target (cross)
├── Hostx86/
│   ├── x86/      # x86 host → x86 target (native)
│   └── x64/      # x86 host → x64 target (cross)
└── Hostarm64/
    ├── arm64/    # ARM64 host → ARM64 target (native)
    ├── x64/      # ARM64 host → x64 target (cross)
    └── x86/      # ARM64 host → x86 target (cross)
```

## Auto-Detection


By default, msvc-kit auto-detects your host architecture:

```bash
# Auto-detect host, target x64

msvc-kit download --arch x64
```

## Common Scenarios


### Build 32-bit on 64-bit Windows


```bash
msvc-kit download --host-arch x64 --arch x86
msvc-kit setup --script --shell powershell | Invoke-Expression

# cl.exe now targets x86

cl /c myfile.cpp  # Produces x86 object file
```

### Build ARM64 for Windows on ARM


```bash
# On x64 machine

msvc-kit download --host-arch x64 --arch arm64
msvc-kit setup --script --shell powershell | Invoke-Expression

# cl.exe now targets ARM64

cl /c myfile.cpp  # Produces ARM64 object file
```

### Multi-Architecture Setup


Download multiple architectures:

```bash
# Download for multiple targets

msvc-kit download --arch x64
msvc-kit download --arch x86
msvc-kit download --arch arm64
```

## Library API


```rust
use msvc_kit::{DownloadOptions, Architecture};

let options = DownloadOptions::builder()
    .arch(Architecture::X64)
    .host_arch(Architecture::X64)
    .target_dir("C:/msvc-kit")
    .build();

// Only x64 packages will be downloaded
let info = msvc_kit::download_msvc(&options).await?;
```

### Cross-Compilation Example


```rust
use msvc_kit::{DownloadOptions, Architecture};

// Build ARM64 binaries on x64 host
let options = DownloadOptions::builder()
    .arch(Architecture::Arm64)
    .host_arch(Architecture::X64)
    .target_dir("C:/msvc-kit")
    .build();

// Downloads: HostX64.TargetARM64 tools + ARM64 CRT/MFC/ATL
let info = msvc_kit::download_msvc(&options).await?;
```