Separate compilation and linker phases (#376)

Separate between compilation and linker phases to allow deploy time
linking and back-porting era compiler changes to fix #91. Unlinked
contract binaries (caused by missing libraries or missing factory
dependencies in turn) are emitted as raw ELF object.

Few drive by fixes:
- #98
- A compiler panic on missing libraries definitions.
- Fixes some incosistent type forwarding in JSON output (empty string
vs. null object).
- Remove the unused fallback for size optimization setting.
- Remove the broken `--lvm-ir`  mode.
- CI workflow fixes.

---------

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>
Signed-off-by: xermicus <bigcyrill@hotmail.com>
Signed-off-by: xermicus <cyrill@parity.io>

crates/solc-json-interface/src/combined_json/selector.rs

@@ -0,0 +1,115 @@
+//! The `solc --combined-json` expected output selection flag.
+
+use std::str::FromStr;
+
+use serde::{Deserialize, Serialize};
+
+/// The solc `--combind-json` invalid selector message.
+pub const MESSAGE_SELECTOR_INVALID: &str = "Invalid option to --combined-json";
+
+/// The `solc --combined-json` expected output selection flag.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub enum Selector {
+    /// The ABI JSON.
+    #[serde(rename = "abi")]
+    ABI,
+    /// The function signature hashes JSON.
+    #[serde(rename = "hashes")]
+    Hashes,
+    /// The metadata.
+    #[serde(rename = "metadata")]
+    Metadata,
+    /// The developer documentation.
+    #[serde(rename = "devdoc")]
+    Devdoc,
+    /// The user documentation.
+    #[serde(rename = "userdoc")]
+    Userdoc,
+    /// The storage layout.
+    #[serde(rename = "storage-layout")]
+    StorageLayout,
+    /// The transient storage layout.
+    #[serde(rename = "transient-storage-layout")]
+    TransientStorageLayout,
+    /// The AST JSON.
+    #[serde(rename = "ast")]
+    AST,
+    /// The EVM assembly.
+    #[serde(rename = "asm")]
+    ASM,
+
+    /// The assembly.
+    #[serde(rename = "assembly", skip_serializing)]
+    Assembly,
+
+    /// The deploy bytecode.
+    #[serde(rename = "bin", skip_serializing)]
+    Bytecode,
+    /// The runtime bytecode.
+    #[serde(rename = "bin-runtime", skip_serializing)]
+    BytecodeRuntime,
+}
+
+impl Selector {
+    /// Converts the comma-separated CLI argument into an array of flags.
+    pub fn from_cli(format: &str) -> Vec<anyhow::Result<Self>> {
+        format
+            .split(',')
+            .map(|flag| Self::from_str(flag.trim()))
+            .collect()
+    }
+
+    /// Whether the selector is available in `solc`.
+    pub fn is_source_solc(&self) -> bool {
+        !matches!(
+            self,
+            Self::Assembly | Self::Bytecode | Self::BytecodeRuntime
+        )
+    }
+}
+
+impl FromStr for Selector {
+    type Err = anyhow::Error;
+
+    fn from_str(string: &str) -> Result<Self, Self::Err> {
+        match string {
+            "abi" => Ok(Self::ABI),
+            "hashes" => Ok(Self::Hashes),
+            "metadata" => Ok(Self::Metadata),
+            "devdoc" => Ok(Self::Devdoc),
+            "userdoc" => Ok(Self::Userdoc),
+            "storage-layout" => Ok(Self::StorageLayout),
+            "transient-storage-layout" => Ok(Self::TransientStorageLayout),
+            "ast" => Ok(Self::AST),
+            "asm" => Ok(Self::ASM),
+
+            "bin" => Ok(Self::Bytecode),
+            "bin-runtime" => Ok(Self::BytecodeRuntime),
+
+            "assembly" => Ok(Self::Assembly),
+
+            selector => anyhow::bail!("{MESSAGE_SELECTOR_INVALID}: {selector}"),
+        }
+    }
+}
+
+impl std::fmt::Display for Selector {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Self::ABI => write!(f, "abi"),
+            Self::Hashes => write!(f, "hashes"),
+            Self::Metadata => write!(f, "metadata"),
+            Self::Devdoc => write!(f, "devdoc"),
+            Self::Userdoc => write!(f, "userdoc"),
+            Self::StorageLayout => write!(f, "storage-layout"),
+            Self::TransientStorageLayout => write!(f, "transient-storage-layout"),
+            Self::AST => write!(f, "ast"),
+            Self::ASM => write!(f, "asm"),
+
+            Self::Bytecode => write!(f, "bin"),
+            Self::BytecodeRuntime => write!(f, "bin-runtime"),
+
+            Self::Assembly => write!(f, "assembly"),
+        }
+    }
+}