trans: Inform LLVM we want CodeView on MSVC

This mirrors the behavior of `clang-cl.exe` by adding a `CodeView` global
variable when emitting debug information. This should in turn help stack traces
that are generated when code is compiled with debuginfo enabled.

Closes #28133

Author: alexcrichton

src/librustc_trans/trans/debuginfo/mod.rs

@@ -200,6 +200,13 @@ pub fn finalize(cx: &CrateContext) {
                                         2)
         }
 
+        // Indicate that we want CodeView debug information on MSVC
+        if cx.sess().target.target.options.is_like_msvc {
+            llvm::LLVMRustAddModuleFlag(cx.llmod(),
+                                        "CodeView\0".as_ptr() as *const _,
+                                        1)
+        }
+
         // Prevent bitcode readers from deleting the debug info.
         let ptr = "Debug Info Version\0".as_ptr();
         llvm::LLVMRustAddModuleFlag(cx.llmod(), ptr as *const _,

src/test/run-pass/backtrace-debuginfo.rs

@@ -14,6 +14,7 @@
 // seemingly completely unrelated change.
 // Unfortunately, LLVM has no "disable" option for this, so we have to set
 // "enable" to 0 instead.
+
 // compile-flags:-g -Cllvm-args=-enable-tail-merge=0
 // ignore-pretty as this critically relies on line numbers
 
@@ -27,30 +28,23 @@ macro_rules! pos {
     () => ((file!(), line!()))
 }
 
-#[cfg(all(unix,
-          not(target_os = "macos"),
-          not(target_os = "ios"),
-          not(target_os = "android"),
-          not(all(target_os = "linux", target_arch = "arm"))))]
 macro_rules! dump_and_die {
     ($($pos:expr),*) => ({
         // FIXME(#18285): we cannot include the current position because
         // the macro span takes over the last frame's file/line.
-        dump_filelines(&[$($pos),*]);
-        panic!();
+        if cfg!(target_os = "macos") ||
+           cfg!(target_os = "ios") ||
+           cfg!(target_os = "android") ||
+           cfg!(all(target_os = "linux", target_arch = "arm")) ||
+           cfg!(all(windows, target_env = "gnu")) {
+            // skip these platforms as this support isn't implemented yet.
+        } else {
+            dump_filelines(&[$($pos),*]);
+            panic!();
+        }
     })
 }
 
-// this does not work on Windows, Android, OSX or iOS
-#[cfg(not(all(unix,
-              not(target_os = "macos"),
-              not(target_os = "ios"),
-              not(target_os = "android"),
-              not(all(target_os = "linux", target_arch = "arm")))))]
-macro_rules! dump_and_die {
-    ($($pos:expr),*) => ({ let _ = [$($pos),*]; })
-}
-
 // we can't use a function as it will alter the backtrace
 macro_rules! check {
     ($counter:expr; $($pos:expr),*) => ({

src/test/run-pass/backtrace.rs

@@ -10,12 +10,11 @@
 
 // no-pretty-expanded FIXME #15189
 // ignore-android FIXME #17520
-// ignore-msvc FIXME #28133
+// compile-flags:-g
 
 use std::env;
 use std::process::{Command, Stdio};
 use std::str;
-use std::ops::{Drop, FnMut, FnOnce};
 
 #[inline(never)]
 fn foo() {
@@ -52,7 +51,7 @@ fn runtest(me: &str) {
     let out = p.wait_with_output().unwrap();
     assert!(!out.status.success());
     let s = str::from_utf8(&out.stderr).unwrap();
-    assert!(s.contains("stack backtrace") && s.contains("foo::h"),
+    assert!(s.contains("stack backtrace") && s.contains(" - foo"),
             "bad output: {}", s);
 
     // Make sure the stack trace is *not* printed
@@ -62,7 +61,7 @@ fn runtest(me: &str) {
     let out = p.wait_with_output().unwrap();
     assert!(!out.status.success());
     let s = str::from_utf8(&out.stderr).unwrap();
-    assert!(!s.contains("stack backtrace") && !s.contains("foo::h"),
+    assert!(!s.contains("stack backtrace") && !s.contains(" - foo"),
             "bad output2: {}", s);
 
     // Make sure a stack trace is printed
@@ -72,7 +71,7 @@ fn runtest(me: &str) {
     let s = str::from_utf8(&out.stderr).unwrap();
     // loosened the following from double::h to double:: due to
     // spurious failures on mac, 32bit, optimized
-    assert!(s.contains("stack backtrace") && s.contains("double::"),
+    assert!(s.contains("stack backtrace") && s.contains(" - double"),
             "bad output3: {}", s);
 
     // Make sure a stack trace isn't printed too many times
@@ -89,8 +88,11 @@ fn runtest(me: &str) {
             "bad output4: {}", s);
 }
 
-#[cfg(not(all(windows, target_arch = "x86")))]
 fn main() {
+    if cfg!(windows) && cfg!(target_arch = "x86") && cfg!(target_env = "gnu") {
+        return
+    }
+
     let args: Vec<String> = env::args().collect();
     if args.len() >= 2 && args[1] == "fail" {
         foo();
@@ -100,7 +102,3 @@ fn main() {
         runtest(&args[0]);
     }
 }
-
-// See issue 28218
-#[cfg(all(windows, target_arch = "x86"))]
-fn main() {}