Improve backtrace formating while panicking.

- `RUST_BACKTRACE=full` prints all the informations (old behaviour)
- `RUST_BACKTRACE=(0|no)` disables the backtrace.
- `RUST_BACKTRACE=<everything else>` (including `1`) shows a simplified
  backtrace, without the function addresses and with cleaned filenames
  and symbols. Also removes some unneded frames at the beginning and the
  end.

Fixes #37783.

PR is #38165.

2 files changed, 103 insertions, 0 deletions

diff --git a/src/libstd/sys/windows/backtrace/printing/mod.rs b/src/libstd/sys/windows/backtrace/printing/mod.rs
new file mode 100644
index 00000000000..3e566f6e2bd
--- /dev/null
+++ b/src/libstd/sys/windows/backtrace/printing/mod.rs
@@ -0,0 +1,20 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[cfg(target_env = "msvc")]
+#[path = "msvc.rs"]
+mod printing;
+
+#[cfg(target_env = "gnu")]
+mod printing {
+    pub use sys_common::gnu::libbacktrace::{foreach_symbol_fileline, resolve_symname};
+}
+
+pub use self::printing::{foreach_symbol_fileline, resolve_symname};
diff --git a/src/libstd/sys/windows/backtrace/printing/msvc.rs b/src/libstd/sys/windows/backtrace/printing/msvc.rs
new file mode 100644
index 00000000000..3107d784324
--- /dev/null
+++ b/src/libstd/sys/windows/backtrace/printing/msvc.rs
@@ -0,0 +1,83 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use ffi::CStr;
+use io;
+use libc::{c_ulong, c_int, c_char};
+use mem;
+use sys::c;
+use sys::backtrace::BacktraceContext;
+use sys_common::backtrace::Frame;
+
+type SymFromAddrFn =
+    unsafe extern "system" fn(c::HANDLE, u64, *mut u64,
+                              *mut c::SYMBOL_INFO) -> c::BOOL;
+type SymGetLineFromAddr64Fn =
+    unsafe extern "system" fn(c::HANDLE, u64, *mut u32,
+                              *mut c::IMAGEHLP_LINE64) -> c::BOOL;
+
+/// Converts a pointer to symbol to its string value.
+pub fn resolve_symname<F>(frame: Frame,
+                          callback: F,
+                          context: &BacktraceContext) -> io::Result<()>
+    where F: FnOnce(Option<&str>) -> io::Result<()>
+{
+    let SymFromAddr = sym!(&context.dbghelp, "SymFromAddr", SymFromAddrFn)?;
+
+    unsafe {
+        let mut info: c::SYMBOL_INFO = mem::zeroed();
+        info.MaxNameLen = c::MAX_SYM_NAME as c_ulong;
+        // the struct size in C.  the value is different to
+        // `size_of::<SYMBOL_INFO>() - MAX_SYM_NAME + 1` (== 81)
+        // due to struct alignment.
+        info.SizeOfStruct = 88;
+
+        let mut displacement = 0u64;
+        let ret = SymFromAddr(context.handle,
+                              frame.symbol_addr as u64,
+                              &mut displacement,
+                              &mut info);
+
+        let symname = if ret == c::TRUE {
+            let ptr = info.Name.as_ptr() as *const c_char;
+            CStr::from_ptr(ptr).to_str().ok()
+        } else {
+            None
+        };
+        callback(symname)
+    }
+}
+
+pub fn foreach_symbol_fileline<F>(frame: Frame,
+                                  mut f: F,
+                                  context: &BacktraceContext)
+    -> io::Result<bool>
+    where F: FnMut(&[u8], c_int) -> io::Result<()>
+{
+    let SymGetLineFromAddr64 = sym!(&context.dbghelp,
+                                    "SymGetLineFromAddr64",
+                                    SymGetLineFromAddr64Fn)?;
+
+    unsafe {
+        let mut line: c::IMAGEHLP_LINE64 = mem::zeroed();
+        line.SizeOfStruct = ::mem::size_of::<c::IMAGEHLP_LINE64>() as u32;
+
+        let mut displacement = 0u32;
+        let ret = SymGetLineFromAddr64(context.handle,
+                                       frame.exact_position as u64,
+                                       &mut displacement,
+                                       &mut line);
+        if ret == c::TRUE {
+            let name = CStr::from_ptr(line.Filename).to_bytes();
+            f(name, line.LineNumber as c_int)?;
+        }
+        Ok(false)
+    }
+}