LLVM Code Coverage Instrumentation

.gitignore

@@ -10,3 +10,5 @@
 *.a
 *.elf
 *.out
+default.profraw
+default.profexport

Cargo.toml

@@ -21,6 +21,7 @@ plc_source = { path = "./compiler/plc_source" }
 plc_ast = { path = "./compiler/plc_ast" }
 plc_util = { path = "./compiler/plc_util" }
 plc_diagnostics = { path = "./compiler/plc_diagnostics" }
+rustc_llvm_coverage = { path = "./compiler/rustc_llvm_coverage" }
 logos = "0.12.0"
 thiserror = "1.0"
 clap = { version = "3.0", features = ["derive"] }
@@ -69,11 +70,13 @@ members = [
 	"compiler/plc_util",
 	"compiler/plc_xml",
 	"compiler/plc_derive",
+	"compiler/rustc_llvm",
+	"compiler/rustc_llvm_coverage",
 ]
 default-members = [".", "compiler/plc_driver", "compiler/plc_xml"]
 
 [workspace.dependencies]
-inkwell = { version = "0.2", features = ["llvm14-0"] }
+inkwell = { git = "https://github.com/corbanvilla/inkwell.git", branch = "v2.0", version = "0.2", features = ["llvm14-0"] }
 encoding_rs = "0.8"
 encoding_rs_io = "0.1"
 log = "0.4"

compiler/plc_source/src/source_location.rs

@@ -296,6 +296,19 @@ impl SourceLocation {
             true
         }
     }
+
+    // TOOD - there's probably a better way to do this
+    pub fn get_start_end(&self) -> (usize, usize, usize, usize) {
+        let span = self.get_span();
+        if let CodeSpan::Range(range) = span {
+            let (start_line, start_col, end_line, end_col) =
+                // TODO - rusty devs will understand what needs to be done here w/ line + 1
+                (range.start.line + 1, range.start.column + 1, range.end.line + 1, range.end.column + 1);
+            (start_line, start_col, end_line, end_col)
+        } else {
+            panic!("Error: expected CodeSpan::Range, found {:?}", span);
+        }
+    }
 }
 
 /**

compiler/rustc_llvm/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "rustc_llvm"
+version = "0.0.0"
+edition = "2021"
+
+[features]
+static-libstdcpp = []
+emscripten = []
+
+[dependencies]
+libc = "0.2.73"
+
+[build-dependencies]
+cc = "1.0.69"

compiler/rustc_llvm/README.md

@@ -0,0 +1,5 @@
+# `rustc-llvm`
+
+This package serves to wrap some of the LLVM functions which are not natively exposed as part of the LLVM C-API, in a Rust-friendly way. 
+
+This code is taken directly from the [Rust compiler source code (version 1.64.0)](https://github.com/rust-lang/rust/tree/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52), which is the last version of the Rust compiler to use LLVM 14 (which is currently the version used by `ruSTy`). The Rust compiler uses this code to interface with LLVM in order to add code coverage instrumentation to Rust binaries, among other features.