QL: Add tool for extracting blame info

I had some trouble getting this to work with version 1.54 of the Rust
toolchain, so I had to bump it up to 1.59.

ql/Cargo.toml

@@ -4,4 +4,5 @@ members = [
     "extractor",
     "generator",
     "node-types",
+    "buramu",
 ]

ql/buramu/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "buramu"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+lazy_static = "1.4.0"
+chrono = "0.4.23"
+rayon = "1.5.0"
+regex = "1.7.1"

ql/buramu/README.md

@@ -0,0 +1,22 @@
+Gathers up `git blame` information for all lines with `deprecated` annotations in QL files in the
+codebase.
+
+## Usage
+
+From within the root of the `codeql` repo (having first run the `create-extractor-pack.sh` script):
+```
+    ./ql/target/release/buramu > deprecated.blame
+```
+
+## Output
+The contents of the `deprecated.blame` file will look something like this:
+```
+today: 2023-02-17
+file: cpp/ql/lib/semmle/code/cpp/security/TaintTrackingImpl.qll
+  last_modified: 2022-11-25 124 167 173 184 188 329 358 400 415 546 553 584 593
+file: go/ql/lib/semmle/go/security/FlowSources.qll
+  last_modified: 2022-12-19 33
+file: python/ql/src/experimental/semmle/python/Concepts.qll
+  last_modified: 2022-08-18 172 202
+  last_modified: 2022-03-11 94 110 129 145 177 206 225 241 258 272 289 303 454 485 529 570
+```

ql/buramu/src/main.rs

@@ -0,0 +1,108 @@
+use lazy_static::lazy_static;
+use rayon::prelude::*;
+use regex::Regex;
+use std::collections::HashMap;
+use std::{io::BufRead, process::Command};
+
+// A map from filenames to lists of line numbers (for just the lines with deprecations)
+type FileDeprecations = HashMap<String, Vec<String>>;
+
+fn get_filename_and_lineno(line: &str) -> (String, String) {
+    let mut parts = line.splitn(3, ':');
+    let file = parts.next().unwrap().to_string();
+    let lineno = parts.next().unwrap().to_string();
+    (file, lineno)
+}
+
+#[test]
+fn test_get_filename_and_lineno() {
+    let line = "path/to/file.ql:61:deprecated class Foo = Bar;";
+    let (file, lineno) = get_filename_and_lineno(line);
+    assert_eq!(file, "path/to/file.ql");
+    assert_eq!(lineno, "61");
+}
+
+fn get_files_with_deprecations() -> FileDeprecations {
+    let output = Command::new("git")
+        .args(&[
+            "grep",
+            "-n",
+            "-E",
+            "^[^*]*deprecated", // skip lines that have a `*` before `deprecated`, as they are probably comments
+            "--",
+            "*.ql",
+            "*.qll",
+        ])
+        .output()
+        .expect("failed to execute process");
+    let mut file_deprecations: FileDeprecations = HashMap::new();
+    for line in output.stdout.lines() {
+        let (file, lineno) = get_filename_and_lineno(&line.unwrap());
+        file_deprecations
+            .entry(file)
+            .or_insert_with(Vec::new)
+            .push(lineno);
+    }
+    file_deprecations
+}
+
+struct LastModifiedLine {
+    date: String,
+    lineno: String,
+}
+type LastModifiedMap = HashMap<String, Vec<String>>;
+
+fn get_blame_dates_for_filedeprecation(file: &str, linenos: &[String]) -> LastModifiedMap {
+    let mut command = Command::new("git");
+    command.arg("blame");
+    for lineno in linenos {
+        command.arg("-L").arg(format!("{},{}", lineno, lineno));
+    }
+    command.arg(file);
+    let output = command.output().expect("failed to execute process");
+    let mut blame_dates = HashMap::new();
+    for line in output.stdout.lines() {
+        let line = line.unwrap();
+        let LastModifiedLine { date, lineno } = get_last_modified(&line);
+        blame_dates
+            .entry(date)
+            .or_insert_with(Vec::new)
+            .push(lineno);
+    }
+    blame_dates
+}
+
+lazy_static! {
+    static ref BLAME_RE: Regex =
+        Regex::new("(\\d{4}-\\d{2}-\\d{2}).*[+-]\\d{4}\\s+(\\d+)\\)").unwrap();
+}
+
+fn get_last_modified(line: &str) -> LastModifiedLine {
+    let caps = BLAME_RE.captures(line).unwrap();
+    let date = caps.get(1).unwrap().as_str().into();
+    let lineno = caps.get(2).unwrap().as_str().into();
+    LastModifiedLine { date, lineno }
+}
+
+#[test]
+fn test_get_date_and_lineno() {
+    let line = "cc7a9ef97a78 (john doe 2022-08-24 12:59:07 +0200 61) deprecated class Foo = Bar;";
+    let LastModifiedLine { date, lineno } = get_last_modified(line);
+    assert_eq!(date, "2022-08-24");
+    assert_eq!(lineno, "61");
+}
+
+fn main() {
+    let filedeprecations = get_files_with_deprecations();
+    let filedeprecations: Vec<(String, Vec<String>)> = filedeprecations.into_iter().collect();
+    println!("today: {}", chrono::Local::now().format("%Y-%m-%d"));
+    let deprecations = filedeprecations
+        .par_iter()
+        .map(|(file, linenos)| (file, get_blame_dates_for_filedeprecation(file, linenos)));
+    deprecations.for_each(|(file, linenos_and_dates)| {
+        println!("file: {}", file);
+        for (date, linenos) in linenos_and_dates.iter() {
+            println!("  last_modified: {} {}", date, linenos.join(" "));
+        }
+    });
+}

ql/rust-toolchain.toml

@@ -2,6 +2,6 @@
 # extractor. It is set to the lowest version of Rust we want to support.
 
 [toolchain]
-channel = "1.54"
+channel = "1.59"
 profile = "minimal"
 components = [ "rustfmt" ]