run_make_support nm implementation + bin-emit-no-symbols rmake rewrite

Author: Oneirical

library/backtrace

@@ -0,0 +1,48 @@
+use crate::{fs_wrapper, object};
+use object::{Object, ObjectSection};
+use std::path::Path;
+
+#[derive(Debug)]
+pub struct Nm {
+    file: Option<object::File>,
+}
+
+pub fn nm() -> Nm {
+    Nm::new()
+}
+
+impl Nm {
+    /// Construct a bare `nm` invocation.
+    pub fn new() -> Self {
+        Self { file: None }
+    }
+
+    /// Specify the file to analyze the symbols of.
+    pub fn input<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        &mut Self {
+            file: Some(
+                object::File::parse(fs_wrapper::read(path))
+                    .expect(format!("Failed to parse ELF file at {:?}", path.as_ref().display())),
+            ),
+        }
+    }
+
+    /// Collect all symbols of an object file into a String.
+    pub fn collect_symbols(&self) -> String {
+        let object_file = self.file;
+        let mut symbols_str = String::new();
+        for section in object_file.sections() {
+            if let Ok(ObjectSection::SymbolTable(st)) = section.parse::<object::SymbolTable>() {
+                for symbol in st.symbols() {
+                    symbols_str.push_str(&format!(
+                        "{:016x} {:?} {}\n",
+                        symbol.address(),
+                        symbol.kind(),
+                        symbol.name()
+                    ));
+                }
+            }
+        }
+        symbols_str
+    }
+}

src/doc/book

@@ -84,7 +84,6 @@ run-make/issue-37839/Makefile
 run-make/issue-40535/Makefile
 run-make/issue-47384/Makefile
 run-make/issue-47551/Makefile
-run-make/issue-51671/Makefile
 run-make/issue-68794-textrel-on-minimal-lib/Makefile
 run-make/issue-69368/Makefile
 run-make/issue-83045/Makefile

src/doc/edition-guide

@@ -0,0 +1,19 @@
+// When setting the crate type as a "bin" (in app.rs),
+// this could cause a bug where some symbols would not be
+// emitted in the object files. This has been fixed, and
+// this test checks that the correct symbols have been successfully
+// emitted inside the object files.
+// See https://github.com/rust-lang/rust/issues/51671
+
+use run_make_support::{nm, rustc, tmp_dir};
+
+fn main() {
+    rustc().emit("obj").input("app.rs").run();
+    //FIXME(Oneirical): This should eventually be rmake_out_path
+    let nm = nm(tmp_dir().join("app.o"));
+    assert!(
+        nm.contains("rust_begin_unwind")
+            && nm.contains("rust_eh_personality")
+            && nm.contains("__rg_oom")
+    );
+}