Add crate to debug missing dynamic libraries on Windows (#1713)

Add a CLI tool and library code to debug missing dynamic library errors on Windows.

The implementation manually edits the registry global flags for an image file to temporarily enable loader snaps, runs the target under our custom debugger to collect the debug output strings, then parses them for informative loading errors. It does not depend on the presence of `gflags.exe`.

This detects both dynamic linking (and thus process startup) errors, as well as dynamic loading (`LoadLibrary`) errors. It can report multiple missing dynamically-linked libraries.

src/agent/Cargo.toml

@@ -3,6 +3,7 @@ members = [
     "atexit",
     "coverage",
     "debugger",
+    "dynamic-library",
     "input-tester",
     "onefuzz",
     "onefuzz-agent",

src/agent/dynamic-library/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "dynamic-library"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+anyhow = "1.0"
+lazy_static = "1.4"
+regex = "1.5"
+structopt = "0.3"
+thiserror = "1.0"
+
+[target.'cfg(windows)'.dependencies]
+debugger = { path = "../debugger" }
+winreg = "0.10"
+
+[dependencies.winapi]
+version = "0.3"
+features = [
+    "dbghelp",
+    "debugapi",
+    "handleapi",
+    "memoryapi",
+    "processthreadsapi",
+    "securitybaseapi",
+    "shellapi",
+    "werapi",
+    "winbase",
+    "winerror"
+]
+
+[[bin]]
+name = "dynamic-library"

src/agent/dynamic-library/src/bin/dynamic-library.rs

@@ -0,0 +1,57 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+#![allow(unused, warnings)]
+
+use std::process::{Command, Stdio};
+
+use anyhow::Result;
+use structopt::StructOpt;
+
+#[derive(Debug, StructOpt)]
+struct Opt {
+    #[structopt(min_values = 1)]
+    argv: Vec<String>,
+
+    #[structopt(short, long)]
+    quiet: bool,
+}
+
+#[cfg(target_os = "windows")]
+fn main() -> Result<()> {
+    let opt = Opt::from_args();
+
+    let exe = &opt.argv[0];
+    let mut cmd = Command::new(exe);
+
+    if let Some(args) = opt.argv.get(1..) {
+        cmd.args(args);
+    }
+
+    if opt.quiet {
+        cmd.stdout(Stdio::null());
+        cmd.stderr(Stdio::null());
+    }
+
+    let missing = dynamic_library::windows::find_missing(cmd)?;
+
+    if missing.is_empty() {
+        println!("no missing libraries");
+    } else {
+        for lib in missing {
+            println!("missing library: {:x?}", lib);
+        }
+    }
+
+    Ok(())
+}
+
+#[cfg(target_os = "linux")]
+fn main() -> Result<()> {
+    todo!()
+}
+
+#[cfg(target_os = "macos")]
+fn main() -> Result<()> {
+    todo!()
+}

src/agent/dynamic-library/src/lib.rs

@@ -0,0 +1,5 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+#[cfg(target_os = "windows")]
+pub mod windows;