move target -> roc_target

compiler/roc_target/src/lib.rs

@@ -0,0 +1,74 @@
+#![warn(clippy::dbg_macro)]
+// See github.com/rtfeldman/roc/issues/800 for discussion of the large_enum_variant check.
+#![allow(clippy::large_enum_variant)]
+
+#[derive(Debug, Clone, Copy)]
+pub struct TargetInfo {
+    pub architecture: Architecture,
+}
+
+impl TargetInfo {
+    pub const fn ptr_width(&self) -> PtrWidth {
+        self.architecture.ptr_width()
+    }
+
+    pub const fn default_x86_64() -> Self {
+        TargetInfo {
+            architecture: Architecture::X86_64,
+        }
+    }
+
+    pub const fn default_wasm32() -> Self {
+        TargetInfo {
+            architecture: Architecture::Wasm32,
+        }
+    }
+}
+
+impl From<&target_lexicon::Triple> for TargetInfo {
+    fn from(triple: &target_lexicon::Triple) -> Self {
+        let architecture = Architecture::from(triple.architecture);
+
+        Self { architecture }
+    }
+}
+
+#[repr(u8)]
+#[derive(Debug, Clone, Copy)]
+pub enum PtrWidth {
+    Bytes4 = 4,
+    Bytes8 = 8,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum Architecture {
+    X86_64,
+    X86_32,
+    Aarch64,
+    Arm,
+    Wasm32,
+}
+
+impl Architecture {
+    pub const fn ptr_width(&self) -> PtrWidth {
+        use Architecture::*;
+
+        match self {
+            X86_64 | Aarch64 | Arm => PtrWidth::Bytes8,
+            X86_32 | Wasm32 => PtrWidth::Bytes4,
+        }
+    }
+}
+
+impl From<target_lexicon::Architecture> for Architecture {
+    fn from(target: target_lexicon::Architecture) -> Self {
+        match target {
+            target_lexicon::Architecture::X86_64 => Architecture::X86_64,
+            target_lexicon::Architecture::X86_32(_) => Architecture::X86_32,
+            target_lexicon::Architecture::Aarch64(_) => Architecture::Aarch64,
+            target_lexicon::Architecture::Arm(_) => Architecture::Arm,
+            target_lexicon::Architecture::Wasm32 => Architecture::Wasm32,
+            _ => unreachable!("unsupported architecture"),
+        }
+    }
+}