Merge "aconfig: improve error messages" into main

tools/aconfig/src/commands.rs

@@ -35,8 +35,15 @@ pub struct Input {
 impl Input {
     fn try_parse_flags(&mut self) -> Result<ProtoParsedFlags> {
         let mut buffer = Vec::new();
-        self.reader.read_to_end(&mut buffer)?;
+        self.reader
+            .read_to_end(&mut buffer)
+            .with_context(|| format!("failed to read {}", self.source))?;
         crate::protos::parsed_flags::try_from_binary_proto(&buffer)
+            .with_context(|| self.error_context())
+    }
+
+    fn error_context(&self) -> String {
+        format!("failed to parse {}", self.source)
     }
 }
 
@@ -53,20 +60,23 @@ pub fn parse_flags(package: &str, declarations: Vec<Input>, values: Vec<Input>)
 
     for mut input in declarations {
         let mut contents = String::new();
-        input.reader.read_to_string(&mut contents)?;
+        input
+            .reader
+            .read_to_string(&mut contents)
+            .with_context(|| format!("failed to read {}", input.source))?;
 
         let flag_declarations = crate::protos::flag_declarations::try_from_text_proto(&contents)
-            .with_context(|| format!("Failed to parse {}", input.source))?;
+            .with_context(|| input.error_context())?;
         ensure!(
             package == flag_declarations.package(),
-            "Failed to parse {}: expected package {}, got {}",
+            "failed to parse {}: expected package {}, got {}",
             input.source,
             package,
             flag_declarations.package()
         );
         for mut flag_declaration in flag_declarations.flag.into_iter() {
             crate::protos::flag_declaration::verify_fields(&flag_declaration)
-                .with_context(|| format!("Failed to parse {}", input.source))?;
+                .with_context(|| input.error_context())?;
 
             // create ParsedFlag using FlagDeclaration and default values
             let mut parsed_flag = ProtoParsedFlag::new();
@@ -101,12 +111,15 @@ pub fn parse_flags(package: &str, declarations: Vec<Input>, values: Vec<Input>)
 
     for mut input in values {
         let mut contents = String::new();
-        input.reader.read_to_string(&mut contents)?;
+        input
+            .reader
+            .read_to_string(&mut contents)
+            .with_context(|| format!("failed to read {}", input.source))?;
         let flag_values = crate::protos::flag_values::try_from_text_proto(&contents)
-            .with_context(|| format!("Failed to parse {}", input.source))?;
+            .with_context(|| input.error_context())?;
         for flag_value in flag_values.flag_value.into_iter() {
             crate::protos::flag_value::verify_fields(&flag_value)
-                .with_context(|| format!("Failed to parse {}", input.source))?;
+                .with_context(|| input.error_context())?;
 
             let Some(parsed_flag) = parsed_flags
                 .parsed_flag

tools/aconfig/src/main.rs

@@ -16,7 +16,7 @@
 
 //! `aconfig` is a build time tool to manage build time configurations, such as feature flags.
 
-use anyhow::{anyhow, bail, ensure, Result};
+use anyhow::{anyhow, bail, Context, Result};
 use clap::{builder::ArgAction, builder::EnumValueParser, Arg, ArgMatches, Command};
 use core::any::Any;
 use std::fs;
@@ -129,26 +129,27 @@ fn open_single_file(matches: &ArgMatches, arg_name: &str) -> Result<Input> {
 }
 
 fn write_output_file_realtive_to_dir(root: &Path, output_file: &OutputFile) -> Result<()> {
-    ensure!(
-        root.is_dir(),
-        "output directory {} does not exist or is not a directory",
-        root.display()
-    );
     let path = root.join(output_file.path.clone());
     let parent = path
         .parent()
         .ok_or(anyhow!("unable to locate parent of output file {}", path.display()))?;
-    fs::create_dir_all(parent)?;
+    fs::create_dir_all(parent)
-    let mut file = fs::File::create(path)?;
+        .with_context(|| format!("failed to create directory {}", parent.display()))?;
-    file.write_all(&output_file.contents)?;
+    let mut file = fs::File::create(path.clone())
+        .with_context(|| format!("failed to open {}", path.display()))?;
+    file.write_all(&output_file.contents)
+        .with_context(|| format!("failed to write to {}", path.display()))?;
     Ok(())
 }
 
 fn write_output_to_file_or_stdout(path: &str, data: &[u8]) -> Result<()> {
     if path == "-" {
-        io::stdout().write_all(data)?;
+        io::stdout().write_all(data).context("failed to write to stdout")?;
     } else {
-        fs::File::create(path)?.write_all(data)?;
+        fs::File::create(path)
+            .with_context(|| format!("failed to open {}", path))?
+            .write_all(data)
+            .with_context(|| format!("failed to write to {}", path))?;
     }
     Ok(())
 }
@@ -160,14 +161,16 @@ fn main() -> Result<()> {
             let package = get_required_arg::<String>(sub_matches, "package")?;
             let declarations = open_zero_or_more_files(sub_matches, "declarations")?;
             let values = open_zero_or_more_files(sub_matches, "values")?;
-            let output = commands::parse_flags(package, declarations, values)?;
+            let output = commands::parse_flags(package, declarations, values)
+                .context("failed to create cache")?;
             let path = get_required_arg::<String>(sub_matches, "cache")?;
             write_output_to_file_or_stdout(path, &output)?;
         }
         Some(("create-java-lib", sub_matches)) => {
             let cache = open_single_file(sub_matches, "cache")?;
             let mode = get_required_arg::<CodegenMode>(sub_matches, "mode")?;
-            let generated_files = commands::create_java_lib(cache, *mode)?;
+            let generated_files =
+                commands::create_java_lib(cache, *mode).context("failed to create java lib")?;
             let dir = PathBuf::from(get_required_arg::<String>(sub_matches, "out")?);
             generated_files
                 .iter()
@@ -176,7 +179,8 @@ fn main() -> Result<()> {
         Some(("create-cpp-lib", sub_matches)) => {
             let cache = open_single_file(sub_matches, "cache")?;
             let mode = get_required_arg::<CodegenMode>(sub_matches, "mode")?;
-            let generated_files = commands::create_cpp_lib(cache, *mode)?;
+            let generated_files =
+                commands::create_cpp_lib(cache, *mode).context("failed to create cpp lib")?;
             let dir = PathBuf::from(get_required_arg::<String>(sub_matches, "out")?);
             generated_files
                 .iter()
@@ -185,25 +189,29 @@ fn main() -> Result<()> {
         Some(("create-rust-lib", sub_matches)) => {
             let cache = open_single_file(sub_matches, "cache")?;
             let mode = get_required_arg::<CodegenMode>(sub_matches, "mode")?;
-            let generated_file = commands::create_rust_lib(cache, *mode)?;
+            let generated_file =
+                commands::create_rust_lib(cache, *mode).context("failed to create rust lib")?;
             let dir = PathBuf::from(get_required_arg::<String>(sub_matches, "out")?);
             write_output_file_realtive_to_dir(&dir, &generated_file)?;
         }
         Some(("create-device-config-defaults", sub_matches)) => {
             let cache = open_single_file(sub_matches, "cache")?;
-            let output = commands::create_device_config_defaults(cache)?;
+            let output = commands::create_device_config_defaults(cache)
+                .context("failed to create device config defaults")?;
             let path = get_required_arg::<String>(sub_matches, "out")?;
             write_output_to_file_or_stdout(path, &output)?;
         }
         Some(("create-device-config-sysprops", sub_matches)) => {
             let cache = open_single_file(sub_matches, "cache")?;
-            let output = commands::create_device_config_sysprops(cache)?;
+            let output = commands::create_device_config_sysprops(cache)
+                .context("failed to create device config sysprops")?;
             let path = get_required_arg::<String>(sub_matches, "out")?;
             write_output_to_file_or_stdout(path, &output)?;
         }
         Some(("dump", sub_matches)) => {
             let input = open_zero_or_more_files(sub_matches, "cache")?;
-            let format = get_required_arg::<DumpFormat>(sub_matches, "format")?;
+            let format = get_required_arg::<DumpFormat>(sub_matches, "format")
+                .context("failed to dump previously parsed flags")?;
             let output = commands::dump_parsed_flags(input, *format)?;
             let path = get_required_arg::<String>(sub_matches, "out")?;
             write_output_to_file_or_stdout(path, &output)?;