Port the without_debuginfo test from backtrace-rs to the testsuite

library/std/src/backtrace.rs

@@ -159,7 +159,10 @@ enum RawFrame {
     Fake,
 }
 
-struct BacktraceSymbol {
+/// A single symbol associated with a backtrace frame, which may include a
+/// function name, filename, line number, and column number.
+#[unstable(feature = "backtrace_internals_accessors", issue = "122899")]
+pub struct BacktraceSymbol {
     name: Option<Vec<u8>>,
     filename: Option<BytesOrWide>,
     lineno: Option<u32>,
@@ -207,6 +210,41 @@ impl fmt::Debug for BacktraceFrame {
     }
 }
 
+///NOTE: This is never intended to become stable. It doesn't have an ACP
+/// Its meant to help us port the tests mentioned in issue #122899
+#[unstable(feature = "backtrace_internals_accessors", issue = "122899")]
+impl BacktraceFrame {
+    /// Returns the instruction pointer associated with this frame.
+    pub fn ip(&self) -> *mut c_void {
+        self.frame.ip()
+    }
+
+    /// Returns the symbols associated with this frame, if any.
+    pub fn symbols(&self) -> &[BacktraceSymbol] {
+        &self.symbols
+    }
+
+    /// Returns the base address of the module this frame belongs to, if available.
+    pub fn module_base_address(&self) -> Option<*mut c_void> {
+        match &self.frame {
+            RawFrame::Actual(frame) => frame.module_base_address(),
+            #[cfg(test)]
+            RawFrame::Fake => None,
+        }
+    }
+}
+
+///NOTE: This is never intended to become stable. It doesn't have an ACP
+/// Its meant to help us port the tests mentioned in issue #122899
+impl BacktraceSymbol {
+    /// Returns the name of this symbol, if available.
+    #[unstable(feature = "backtrace_internals_accessors", issue = "122899")]
+    pub fn name(&self) -> Option<&[u8]> {
+        self.name.as_deref()
+    }
+}
+
+#[unstable(feature = "backtrace_internals_accessors", issue = "122899")]
 impl fmt::Debug for BacktraceSymbol {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         // FIXME: improve formatting: https://github.com/rust-lang/rust/issues/65280

tests/ui/README.md

@@ -973,6 +973,10 @@ See [RFC 3550 New Range](https://github.com/rust-lang/rfcs/blob/master/text/3550
 
 Tests for Non-lexical lifetimes. See [RFC 2094 NLL](https://rust-lang.github.io/rfcs/2094-nll.html).
 
+## `tests/ui/no_debuginfo`: without_debuginfo test ported from backtrace-rs
+
+Tests for behavior when debug information is not available, ported from `backtrace-rs`'s `without_debuginfo` crate's test.
+
 ## `tests/ui/no_std/`
 
 Tests for where the standard library is disabled through `#![no_std]`.

tests/ui/no_debuginfo/all_frames_have_module_base_address.rs

@@ -0,0 +1,20 @@
+//@ compile-flags: -Cstrip=none -Cdebuginfo=none
+//@ run-pass
+#![feature(backtrace_frames)]
+#![feature(backtrace_internals_accessors)]
+use std::backtrace;
+
+fn main() {
+    let mut missing_base_addresses = 0;
+    let btrace = backtrace::Backtrace::force_capture();
+    let frames = btrace.frames();
+    for frame in frames {
+        if frame.module_base_address().is_none() {
+            missing_base_addresses += 1;
+        }
+    }
+
+    if cfg!(windows) {
+        assert_eq!(missing_base_addresses, 0);
+    }
+}

tests/ui/no_debuginfo/all_frames_have_symbols.rs

@@ -0,0 +1,44 @@
+//@ compile-flags: -Cstrip=none -Cdebuginfo=none
+//@ run-pass
+#![feature(backtrace_frames)]
+#![feature(backtrace_internals_accessors)]
+use std::backtrace;
+fn main() {
+    let mut missing_symbols = 0;
+    let mut has_symbols = 0;
+    let btrace = backtrace::Backtrace::force_capture();
+    let frames = btrace.frames();
+    let mut missing_symbol_indices = Vec::new();
+    for (i, frame) in frames.iter().enumerate() {
+        let mut any = false;
+        for sym in frame.symbols() {
+            if sym.name().is_some() {
+                any = true;
+                break;
+            }
+        }
+        if any {
+            has_symbols += 1;
+        } else if !frame.ip().is_null() {
+            missing_symbols += 1;
+            missing_symbol_indices.push(i);
+        }
+    }
+
+    // FIXME(#346) currently on MinGW we can't symbolize kernel32.dll and other
+    // system libraries, which means we miss the last few symbols.
+    if cfg!(windows) && cfg!(target_env = "gnu") {
+        assert!(missing_symbols < has_symbols && has_symbols > 4);
+    } else if cfg!(all(target_os = "linux", target_env = "gnu")) {
+        //NOTE: The reason we allow one missing symbol is because the frame for the
+        // `__libc_start_main` fn doesn't have a symbol. See the discussion in
+        // #152860 for more details.
+        assert!(missing_symbols < has_symbols && missing_symbols <= 1)
+    } else {
+        for i in missing_symbol_indices {
+            eprintln!("missing symbol for frame {i}: {:#?}", frames[i]);
+        }
+        eprintln!("Full erroneous backtrace: {:#?}", btrace);
+        assert_eq!(missing_symbols, 0);
+    }
+}