Introduce Sym::to_path() helper method

This change introduces a helper method for retrieving the source file path to the symbol to the Sym type. We adjust the relevant code snippets to make use of this method as well. Signed-off-by: Daniel Müller <[email protected]>
libbpf · Sep 18, 2023 · 45ac4c4 · 45ac4c4
1 parent 8754cb5
commit 45ac4c4
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Showing 7 changed files with 60 additions and 41 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,6 @@
 Unreleased
 ----------
-- Added `size` member to `symbolize::Sym` type
+- Added `size` member and `to_path` helper to `symbolize::Sym` type
 
 
 0.2.0-alpha.6

diff --git a/cli/src/main.rs b/cli/src/main.rs
@@ -2,8 +2,6 @@
 
 mod args;
 
-use std::path::PathBuf;
-
 use anyhow::Context;
 use anyhow::Result;
 
@@ -109,14 +107,9 @@ fn symbolize(symbolize: args::Symbolize) -> Result<()> {
 
                 let symbolize::Sym {
                     name, addr, offset, ..
-                } = sym;
-
-                let path = match (sym.dir, sym.file) {
-                    (Some(dir), Some(file)) => Some(dir.join(file)),
-                    (dir, file) => dir.or_else(|| file.map(PathBuf::from)),
-                };
+                } = &sym;
 
-                let src_loc = if let (Some(path), Some(line)) = (path, sym.line) {
+                let src_loc = if let (Some(path), Some(line)) = (sym.to_path(), sym.line) {
                     if let Some(col) = sym.column {
                         format!(" {}:{line}:{col}", path.display())
                     } else {

diff --git a/examples/addr2ln.rs b/examples/addr2ln.rs
@@ -1,5 +1,4 @@
 use std::env;
-use std::path::PathBuf;
 
 use anyhow::bail;
 use anyhow::Context as _;
@@ -45,14 +44,9 @@ fn main() -> Result<()> {
 
                 let Sym {
                     name, addr, offset, ..
-                } = sym;
+                } = &sym;
 
-                let path = match (sym.dir, sym.file) {
-                    (Some(dir), Some(file)) => Some(dir.join(file)),
-                    (dir, file) => dir.or_else(|| file.map(PathBuf::from)),
-                };
-
-                let src_loc = if let (Some(path), Some(line)) = (path, sym.line) {
+                let src_loc = if let (Some(path), Some(line)) = (sym.to_path(), sym.line) {
                     if let Some(col) = sym.column {
                         format!(" {}:{line}:{col}", path.display())
                     } else {

diff --git a/examples/addr2ln_pid.rs b/examples/addr2ln_pid.rs
@@ -1,5 +1,4 @@
 use std::env;
-use std::path::PathBuf;
 
 use anyhow::bail;
 use anyhow::Context as _;
@@ -48,14 +47,9 @@ print its symbol, the file name of the source, and the line number.",
 
                 let Sym {
                     name, addr, offset, ..
-                } = sym;
+                } = &sym;
 
-                let path = match (sym.dir, sym.file) {
-                    (Some(dir), Some(file)) => Some(dir.join(file)),
-                    (dir, file) => dir.or_else(|| file.map(PathBuf::from)),
-                };
-
-                let src_loc = if let (Some(path), Some(line)) = (path, sym.line) {
+                let src_loc = if let (Some(path), Some(line)) = (sym.to_path(), sym.line) {
                     if let Some(col) = sym.column {
                         format!(" {}:{line}:{col}", path.display())
                     } else {

diff --git a/examples/backtrace.rs b/examples/backtrace.rs
@@ -1,7 +1,6 @@
 use std::cmp::min;
 use std::mem::size_of;
 use std::mem::transmute;
-use std::path::PathBuf;
 use std::ptr;
 
 use blazesym::symbolize::Process;
@@ -40,14 +39,9 @@ fn symbolize_current_bt() {
 
                 let Sym {
                     name, addr, offset, ..
-                } = sym;
+                } = &sym;
 
-                let path = match (sym.dir, sym.file) {
-                    (Some(dir), Some(file)) => Some(dir.join(file)),
-                    (dir, file) => dir.or_else(|| file.map(PathBuf::from)),
-                };
-
-                let src_loc = if let (Some(path), Some(line)) = (path, sym.line) {
+                let src_loc = if let (Some(path), Some(line)) = (sym.to_path(), sym.line) {
                     if let Some(col) = sym.column {
                         format!(" {}:{line}:{col}", path.display())
                     } else {

diff --git a/src/symbolize/mod.rs b/src/symbolize/mod.rs
@@ -45,14 +45,9 @@
 //!
 //!             let Sym {
 //!                 name, addr, offset, ..
-//!             } = sym;
+//!             } = &sym;
 //!
-//!             let path = match (sym.dir, sym.file) {
-//!                 (Some(dir), Some(file)) => Some(dir.join(file)),
-//!                 (dir, file) => dir.or_else(|| file.map(PathBuf::from)),
-//!             };
-//!
-//!             let src_loc = if let (Some(path), Some(line)) = (path, sym.line) {
+//!             let src_loc = if let (Some(path), Some(line)) = (sym.to_path(), sym.line) {
 //!                 if let Some(col) = sym.column {
 //!                     format!(" {}:{line}:{col}", path.display())
 //!                 } else {

diff --git a/src/symbolize/symbolizer.rs b/src/symbolize/symbolizer.rs
@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::ffi::OsStr;
 use std::ffi::OsString;
 use std::fmt::Debug;
@@ -110,6 +111,25 @@ pub struct Sym {
     pub(crate) _non_exhaustive: (),
 }
 
+impl Sym {
+    /// Helper method to retrieve the path to the represented source file,
+    /// on a best-effort basis. It depends on the symbolization source data
+    /// whether this path is absolute or relative and, if its the latter, what
+    /// directory it is relative to. In general this path is mostly intended for
+    /// displaying purposes.
+    ///
+    /// # Notes
+    /// For the unlikely case that only a source code directory is present, no
+    /// file path will be reported.
+    #[inline]
+    pub fn to_path(&self) -> Option<Cow<'_, Path>> {
+        self.file.as_ref().map(|f| match &self.dir {
+            Some(dir) => Cow::Owned(dir.join(f)),
+            None => Cow::Borrowed(Path::new(f)),
+        })
+    }
+}
+
 
 /// A builder for configurable construction of [`Symbolizer`] objects.
 ///
@@ -501,6 +521,35 @@ mod tests {
     use test_log::test;
 
 
+    /// Check that we can correctly construct the source code path to a symbol.
+    #[test]
+    fn symbol_source_code_path() {
+        let mut sym = Sym {
+            name: "symbol".to_string(),
+            addr: 0x1337,
+            offset: 42,
+            size: Some(43),
+            dir: None,
+            file: None,
+            line: Some(1),
+            column: Some(2),
+            _non_exhaustive: (),
+        };
+        assert_eq!(sym.to_path(), None);
+
+        sym.dir = Some(PathBuf::from("/foobar"));
+        assert_eq!(sym.to_path(), None);
+
+        sym.file = Some(OsString::from("source.c"));
+        assert_eq!(
+            sym.to_path().as_deref(),
+            Some(Path::new("/foobar/source.c"))
+        );
+
+        sym.dir = None;
+        assert_eq!(sym.to_path().as_deref(), Some(Path::new("source.c")));
+    }
+
     /// Check that we can symbolize an address residing in a zip archive.
     #[test]
     fn symbolize_zip() {