From d9efd6635b6bc875427ce84f171ea4b541e623bd Mon Sep 17 00:00:00 2001
From: Mark McCaskey <mark@wasmer.io>
Date: Fri, 13 Dec 2019 14:15:12 -0800
Subject: [PATCH] Store LLVM version info directly in internal_macros

---
 Cargo.toml                 |  1 +
 internal_macros/Cargo.toml |  5 -----
 internal_macros/build.rs   | 41 --------------------------------------
 internal_macros/src/lib.rs | 15 +++++---------
 4 files changed, 6 insertions(+), 56 deletions(-)
 delete mode 100644 internal_macros/build.rs

diff --git a/Cargo.toml b/Cargo.toml
index 62fd67ee11f92..be89eec832518 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,7 @@ edition = "2018"
 
 [features]
 default = ["target-all"]
+# Please update internal_macros::FEATURE_VERSIONS when adding a new LLVM version
 llvm3-6 = []
 llvm3-7 = []
 llvm3-8 = []
diff --git a/internal_macros/Cargo.toml b/internal_macros/Cargo.toml
index c76429513e4db..73269fe966d0d 100644
--- a/internal_macros/Cargo.toml
+++ b/internal_macros/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.1.0"
 authors = ["Daniel Kolsoi <thadan64@gmail.com>"]
 description = "Internal macro crate for inkwell"
 edition = "2018"
-build = "build.rs"
 repository = "https://github.com/TheDan64/inkwell"
 readme = "README.md"
 license = "Apache-2.0"
@@ -14,9 +13,5 @@ quote = "0.6"
 syn = { version = "0.15", features = ["full", "fold"] }
 proc-macro2 = "0.4"
 
-[build-dependencies]
-cargo_toml = "0.8"
-reqwest = "0.9"
-
 [lib]
 proc-macro = true
diff --git a/internal_macros/build.rs b/internal_macros/build.rs
deleted file mode 100644
index d61e889f8530c..0000000000000
--- a/internal_macros/build.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-extern crate cargo_toml;
-
-use cargo_toml::Manifest;
-
-use std::error::Error;
-use std::path::Path;
-
-fn main() {
-    let (manifest, manifest_path) = get_manifest().expect("Unable to load Cargo manifest!");
-    let features = manifest.features
-        .keys()
-        .filter(|feature| feature.as_str().starts_with("llvm"))
-        .cloned()
-        .collect::<Vec<_>>();
-
-    let features_csv = features.as_slice().join(",");
-
-    // Exports a comma-separated feature list in the environment during compilation
-    // Can be fetched with `env!("INKWELL_FEATURES")`
-    println!("cargo:rustc-env=INKWELL_FEATURES={}", features_csv);
-    if let Some(path) = manifest_path {
-        println!("cargo:rerun-if-changed={}", path);
-    }
-}
-
-/// If we're developing locally we should use the local manifest
-/// so that we don't have to duplicate LLVM version info. If we're publishing
-/// then grab the manifest from online since we need internet access to publish anyway.
-fn get_manifest() -> Result<(Manifest, Option<&'static str>), Box<dyn Error>> {
-    const MANIFEST_PATH: &str = "../Cargo.toml";
-
-    Ok(match Manifest::from_path(Path::new(MANIFEST_PATH)) {
-        Ok(m) => (m, Some(MANIFEST_PATH)),
-        Err(_) => {
-            let manifest_str = reqwest::get("https://raw.githubusercontent.com/TheDan64/inkwell/master/Cargo.toml")?.text()?;
-            let manifest = Manifest::from_str(&manifest_str)?;
-
-            (manifest, None)
-        },
-    })
-}
diff --git a/internal_macros/src/lib.rs b/internal_macros/src/lib.rs
index 4cc166f8ae3ed..483477f557126 100644
--- a/internal_macros/src/lib.rs
+++ b/internal_macros/src/lib.rs
@@ -18,14 +18,9 @@ use syn::fold::Fold;
 use syn::spanned::Spanned;
 use syn::{Token, LitFloat, Ident, Item, Field, Variant, Attribute};
 
-const FEATURES_ENV: &str = env!("INKWELL_FEATURES");
-
-/// Fetches a vector of feature version strings, e.g. llvm8-0
-fn get_feature_versions() -> Vec<&'static str> {
-    FEATURES_ENV
-        .split(',')
-        .collect()
-}
+// This array should match the LLVM features in the top level Cargo manifest
+const FEATURE_VERSIONS: [&str; 9] =
+    ["llvm3-6", "llvm3-7", "llvm3-8", "llvm3-9", "llvm4-0", "llvm5-0", "llvm6-0", "llvm7-0", "llvm8-0"];
 
 /// Gets the index of the feature version that represents `latest`
 fn get_latest_feature_index(features: &[&str]) -> usize {
@@ -43,7 +38,7 @@ fn get_feature_index(features: &[&str], feature: String, span: Span) -> Result<u
 
 /// Gets a vector of feature versions represented by the given VersionType
 fn get_features(vt: VersionType) -> Result<Vec<&'static str>> {
-    let features = get_feature_versions();
+    let features = FEATURE_VERSIONS;
     let latest = get_latest_feature_index(&features);
     match vt {
         VersionType::Specific(version, span) => {
@@ -189,7 +184,7 @@ struct FeatureSet(Vec<&'static str>, Option<Error>);
 impl Default for FeatureSet {
     fn default() -> Self {
         // Default to all versions
-        Self(get_feature_versions(), None)
+        Self(FEATURE_VERSIONS.to_vec(), None)
     }
 }
 impl Parse for FeatureSet {