Merge #282

282: Include program counter value in backtrace when -v is passed r=jonathanpallant a=jonas-schievink

This can help when debugging.

```
stack backtrace:
   0: 0x000015b0 @ HardFaultTrampoline
      <exception entry>
   1: 0x000008de @ lib::inline::__udf
        at ./asm/inline.rs:172:5
   2: 0x000008de @ __udf
        at ./asm/lib.rs:49:17
   3: 0x000001c8 @ cortex_m::asm::udf
        at [cortex-m-0.7.3]/src/asm.rs:43:5
   4: 0x000001d2 @ _defmt_panic
        at /tmp/app/src/lib.rs:11:5
   5: 0x000001be @ defmt::export::panic
        at /home/japaric/.cargo/git/checkouts/defmt-52fbd7917982cfac/e021e7d/src/export.rs:266:14
   6: 0x000001be @ panic::__cortex_m_rt_main
        at /tmp/app/src/bin/panic.rs:8:5
   7: 0x00000194 @ main
        at /tmp/app/src/bin/panic.rs:6:1
   8: 0x000001dc @ ResetTrampoline
        at [cortex-m-rt-0.6.14]/src/lib.rs:547:26
   9: 0x0000018a @ Reset
        at [cortex-m-rt-0.6.14]/src/lib.rs:550:13
```

Co-authored-by: Jonas Schievink <[email protected]>

Cargo.toml

@@ -20,7 +20,6 @@ addr2line = { version = "0.15", default-features = false, features = [
 anyhow = "1"
 colored = "2"
 defmt-decoder = { version = "=0.3.0", features = ["unstable"] }
-either = "1.6"
 gimli = { version = "0.24", default-features = false }
 git-version = "0.3"
 log = "0.4"

src/backtrace/mod.rs

@@ -33,6 +33,7 @@ pub(crate) struct Settings<'p> {
     pub(crate) panic_present: bool,
     pub(crate) backtrace_limit: u32,
     pub(crate) shorten_paths: bool,
+    pub(crate) include_addresses: bool,
 }
 
 /// (virtually) unwinds the target's program and prints its backtrace

src/backtrace/pp.rs

@@ -1,6 +1,6 @@
 //! Pretty printing the backtrace
 
-use std::borrow::Cow;
+use std::{borrow::Cow, fmt::Write};
 
 use colored::Colorize as _;
 
@@ -20,18 +20,23 @@ pub(crate) fn backtrace(frames: &[Frame], settings: &Settings) {
             }
 
             Frame::Subroutine(subroutine) => {
-                let name = match &subroutine.name_or_pc {
-                    either::Either::Left(name) => Cow::Borrowed(name),
-                    either::Either::Right(pc) => Cow::Owned(format!("??? (PC={:#010x})", pc)),
-                };
-
                 let is_local_function = subroutine
                     .location
                     .as_ref()
                     .map(|location| location.path_is_relative)
                     .unwrap_or(false);
 
-                let line = format!("{:>4}: {}", frame_index, name);
+                let mut line = format!("{:>4}:", frame_index);
+                if settings.include_addresses || subroutine.name.is_none() {
+                    write!(line, " {:#010x} @", subroutine.pc).unwrap();
+                }
+                write!(
+                    line,
+                    " {}",
+                    subroutine.name.as_deref().unwrap_or("<unknown>")
+                )
+                .unwrap();
+
                 let colorized_line = if is_local_function {
                     line.bold()
                 } else {

src/backtrace/symbolicate.rs

@@ -7,7 +7,6 @@ use std::{
 };
 
 use addr2line::fallible_iterator::FallibleIterator as _;
-use either::Either;
 use gimli::{EndianReader, RunTimeEndian};
 use object::{Object as _, SymbolMap, SymbolMapName};
 
@@ -52,7 +51,8 @@ pub(crate) enum Frame {
 /// "Symbolicated" and de-inlined subroutine frame
 #[derive(Debug)]
 pub(crate) struct Subroutine {
-    pub(crate) name_or_pc: Either<String, u32>,
+    pub(crate) name: Option<String>,
+    pub(crate) pc: u32,
     pub(crate) location: Option<Location>,
 }
 
@@ -116,9 +116,7 @@ impl Subroutine {
 
             // XXX if there was inlining AND there's no function name info we'll report several
             // frames with the same PC
-            let name_or_pc = demangled_name
-                .map(Either::Left)
-                .unwrap_or_else(|| name_from_symtab(pc, symtab));
+            let name = demangled_name.or_else(|| name_from_symtab(pc, symtab));
 
             let location = if let Some((file, line, column)) =
                 frame.location.as_ref().and_then(|loc| {
@@ -142,24 +140,22 @@ impl Subroutine {
                 None
             };
 
-            subroutines.push(Subroutine {
-                name_or_pc,
-                location,
-            })
+            subroutines.push(Subroutine { name, pc, location })
         }
 
         Some(subroutines)
     }
 
     fn from_symtab(pc: u32, symtab: &SymbolMap<SymbolMapName>) -> Subroutine {
         Subroutine {
-            name_or_pc: name_from_symtab(pc, symtab),
+            name: name_from_symtab(pc, symtab),
+            pc,
             location: None,
         }
     }
 }
 
-fn name_from_symtab(pc: u32, symtab: &SymbolMap<SymbolMapName>) -> Either<String, u32> {
+fn name_from_symtab(pc: u32, symtab: &SymbolMap<SymbolMapName>) -> Option<String> {
     // the .symtab appears to use address ranges that have their thumb bits set (e.g.
     // `0x101..0x200`). Passing the `pc` with the thumb bit cleared (e.g. `0x100`) to the
     // lookup function sometimes returns the *previous* symbol. Work around the issue by
@@ -169,8 +165,6 @@ fn name_from_symtab(pc: u32, symtab: &SymbolMap<SymbolMapName>) -> Either<String
     symtab
         .get(address)
         .map(|symbol| addr2line::demangle_auto(symbol.name().into(), None).into_owned())
-        .map(Either::Left)
-        .unwrap_or(Either::Right(pc))
 }
 
 #[derive(Debug)]

src/cli.rs

@@ -47,9 +47,9 @@ pub(crate) struct Opts {
     #[structopt(long)]
     pub(crate) connect_under_reset: bool,
 
-    /// Enable more verbose logging.
+    /// Enable more verbose output.
     #[structopt(short, long, parse(from_occurrences))]
-    verbose: u32,
+    pub(crate) verbose: u32,
 
     /// Prints version information
     #[structopt(short = "V", long)]

src/main.rs

@@ -153,6 +153,7 @@ fn run_target_program(elf_path: &Path, chip_name: &str, opts: &cli::Opts) -> any
         backtrace: (&opts.backtrace).into(),
         panic_present,
         shorten_paths: opts.shorten_paths,
+        include_addresses: opts.verbose > 0,
     };
 
     let mut outcome = backtrace::print(

tests/snapshots/test__panic_verbose.snap

@@ -15,13 +15,13 @@ expression: run_result.output
 (HOST) INFO  flashing program (6.57 KiB)
 (HOST) INFO  success!
 (HOST) DEBUG 261062 bytes of stack available (0x20000000 ..= 0x2003FBC7), using 1024 byte canary
-(HOST) TRACE setting up canary took 0.012s (83.61 KiB/s)
+(HOST) TRACE setting up canary took 0.014s (71.21 KiB/s)
 (HOST) DEBUG starting device
 (HOST) DEBUG Successfully attached RTT
 ────────────────────────────────────────────────────────────────────────────────
 ERROR panicked at 'explicit panic'
 ────────────────────────────────────────────────────────────────────────────────
-(HOST) TRACE reading canary took 0.011s (92.16 KiB/s)
+(HOST) TRACE reading canary took 0.014s (72.39 KiB/s)
 (HOST) DEBUG stack canary intact
 (HOST) DEBUG LR=0xFFFFFFF9 PC=0x000015B0
 (HOST) DEBUG LR=0x000001C9 PC=0x000008DE
@@ -37,26 +37,35 @@ ERROR panicked at 'explicit panic'
 (HOST) DEBUG LR=0x0000018B PC=0x000001DC
 (HOST) DEBUG update_cfa: CFA changed Some(2003fbc0) -> 2003fbc8
 (HOST) DEBUG LR=0xFFFFFFFF PC=0x0000018A
+(HOST) TRACE demangle Ok("_ZN3lib6inline5__udf17h4878bf20408765ceE") (language=Some(DwLang(1C))) -> Ok("lib::inline::__udf")
+(HOST) TRACE demangle Ok("__udf") (language=Some(DwLang(1C))) -> Ok("__udf")
+(HOST) TRACE demangle Ok("_ZN8cortex_m3asm3udf17h4c0f9f15c9bfd7bfE") (language=Some(DwLang(1C))) -> Ok("cortex_m::asm::udf")
+(HOST) TRACE demangle Ok("_defmt_panic") (language=Some(DwLang(1C))) -> Ok("_defmt_panic")
+(HOST) TRACE demangle Ok("_ZN5defmt6export5panic17h3fabd155b5d3f035E") (language=Some(DwLang(1C))) -> Ok("defmt::export::panic")
+(HOST) TRACE demangle Ok("_ZN5panic18__cortex_m_rt_main17hdf4a9d08e66ae2a1E") (language=Some(DwLang(1C))) -> Ok("panic::__cortex_m_rt_main")
+(HOST) TRACE demangle Ok("main") (language=Some(DwLang(1C))) -> Ok("main")
+(HOST) TRACE demangle Ok("ResetTrampoline") (language=Some(DwLang(1C))) -> Ok("ResetTrampoline")
+(HOST) TRACE demangle Ok("Reset") (language=Some(DwLang(1C))) -> Ok("Reset")
 stack backtrace:
-   0: HardFaultTrampoline
+   0: 0x000015b0 @ HardFaultTrampoline
       <exception entry>
-   1: lib::inline::__udf
+   1: 0x000008de @ lib::inline::__udf
         at ./asm/inline.rs:172:5
-   2: __udf
+   2: 0x000008de @ __udf
         at ./asm/lib.rs:49:17
-   3: cortex_m::asm::udf
+   3: 0x000001c8 @ cortex_m::asm::udf
         at [cortex-m-0.7.3]/src/asm.rs:43:5
-   4: _defmt_panic
+   4: 0x000001d2 @ _defmt_panic
         at /tmp/app/src/lib.rs:11:5
-   5: defmt::export::panic
+   5: 0x000001be @ defmt::export::panic
         at /home/japaric/.cargo/git/checkouts/defmt-52fbd7917982cfac/e021e7d/src/export.rs:266:14
-   6: panic::__cortex_m_rt_main
+   6: 0x000001be @ panic::__cortex_m_rt_main
         at /tmp/app/src/bin/panic.rs:8:5
-   7: main
+   7: 0x00000194 @ main
         at /tmp/app/src/bin/panic.rs:6:1
-   8: ResetTrampoline
+   8: 0x000001dc @ ResetTrampoline
         at [cortex-m-rt-0.6.14]/src/lib.rs:547:26
-   9: Reset
+   9: 0x0000018a @ Reset
         at [cortex-m-rt-0.6.14]/src/lib.rs:550:13
 (HOST) ERROR the program panicked