add basic config file, use codemap_diagnostic for main errors

1 files changed, 107 insertions, 0 deletions

diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..4463479
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,107 @@
+use anyhow::{anyhow, Context, Result};
+use codemap::CodeMap;
+use codemap_diagnostic::Diagnostic;
+use serde_derive::{Deserialize, Serialize};
+use structopt::StructOpt;
+use thiserror::Error;
+
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+pub(super) const DEFAULT_PROJECT_CONFIGURATION_FILE_NAME: &str = "poseidoc.toml";
+
+#[derive(Debug, Clone, StructOpt, Deserialize, Serialize)]
+#[structopt(rename_all = "kebab-case")]
+#[serde(rename_all = "kebab-case", default)]
+pub(crate) struct Config {
+    #[structopt(skip)]
+    pub(crate) name: String,
+    #[structopt(long, default_value = ".")]
+    pub(crate) compile_commands_location: PathBuf,
+    #[structopt(skip = vec![])]
+    pub(crate) extra_clang_args: Vec<String>,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            name: "My Project".into(),
+            compile_commands_location: PathBuf::from(r"."),
+            extra_clang_args: Vec::new(),
+        }
+    }
+}
+
+pub(super) fn load_config(location: impl AsRef<Path>, codemap: &mut CodeMap) -> Result<Config> {
+    let location = location.as_ref();
+
+    let final_path = if location.is_dir() {
+        location.join(DEFAULT_PROJECT_CONFIGURATION_FILE_NAME)
+    } else if !location.exists() {
+        return Err(anyhow!("File {:?} does not exists", location))
+            .with_context(|| format!("Failed to open project configuration: {:?}", location));
+    } else {
+        location.to_owned()
+    };
+
+    let config_str =
+        std::fs::read_to_string(&final_path).map_err(|err| ConfigLoadError::IoError {
+            file_name: final_path.clone(),
+            source: err,
+        })?;
+    Ok(
+        toml::from_str(&config_str).map_err(|err| ConfigLoadError::TomlDeserialzation {
+            file: codemap.add_file(final_path.to_string_lossy().into(), config_str),
+            source: err,
+        })?,
+    )
+}
+
+#[derive(Debug, Error)]
+#[error("Error loading project configuration")]
+pub(crate) enum ConfigLoadError {
+    #[error("Failed to read project configuration: {:?}", file_name)]
+    IoError {
+        file_name: PathBuf,
+        source: std::io::Error,
+    },
+    #[error("Failed to parse project configuration: {:?}", file.name())]
+    TomlDeserialzation {
+        file: Arc<codemap::File>,
+        source: toml::de::Error,
+    },
+}
+
+impl From<&ConfigLoadError> for Diagnostic {
+    fn from(err: &ConfigLoadError) -> Diagnostic {
+        use codemap_diagnostic::{Level, SpanLabel, SpanStyle};
+        use std::convert::TryInto;
+
+        let message = err.to_string();
+
+        let spans = match err {
+            ConfigLoadError::IoError { .. } => vec![],
+            ConfigLoadError::TomlDeserialzation { file, source, .. } => {
+                if let Some((line, col)) = source.line_col() {
+                    let line_span = file.line_span(line);
+                    let col = col.try_into().unwrap();
+                    let span = line_span.subspan(col, col);
+                    vec![SpanLabel {
+                        span,
+                        label: None,
+                        style: SpanStyle::Primary,
+                    }]
+                } else {
+                    vec![]
+                }
+            }
+        };
+
+        Diagnostic {
+            level: Level::Error,
+            message,
+            code: None,
+            spans,
+        }
+    }
+}