Finish up Miri integration (#376)

* Use `fn_ptr` from Miri

* Get tests passing under Miri

* Test Miri on CI

.github/workflows/main.yml

@@ -192,3 +192,14 @@ jobs:
     - name: Install Rust
       run: rustup update 1.40.0 && rustup default 1.40.0
     - run: cargo build
+
+  miri:
+    name: Miri
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+      with:
+        submodules: true
+    - name: Install Rust
+      run: ./ci/miri-rustup.sh
+    - run: MIRIFLAGS="-Zmiri-disable-isolation" cargo miri test

ci/miri-rustup.sh

@@ -0,0 +1,7 @@
+set -ex
+
+MIRI_NIGHTLY=nightly-$(curl -s https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu/miri)
+echo "Installing latest nightly with Miri: $MIRI_NIGHTLY"
+rustup set profile minimal
+rustup default "$MIRI_NIGHTLY"
+rustup component add miri

src/backtrace/miri.rs

@@ -13,6 +13,7 @@ pub struct MiriFrame {
     pub filename: Box<[u8]>,
     pub lineno: u32,
     pub colno: u32,
+    pub fn_ptr: *mut c_void,
 }
 
 #[derive(Debug, Clone)]
@@ -36,7 +37,7 @@ impl Frame {
     }
 
     pub fn symbol_address(&self) -> *mut c_void {
-        self.addr
+        self.inner.fn_ptr
     }
 
     pub fn module_base_address(&self) -> Option<*mut c_void> {

tests/accuracy/main.rs

@@ -22,6 +22,8 @@ fn doit() {
     !cfg!(target_env = "musl")
     // Skip MinGW on libbacktrace which doesn't have support for DLLs.
     && !(cfg!(windows) && cfg!(target_env = "gnu") && cfg!(feature = "libbacktrace"))
+    // Skip Miri, since it doesn't support dynamic libraries.
+    && !cfg!(miri)
     {
         // TODO(#238) this shouldn't have to happen first in this function, but
         // currently it does.

tests/concurrent-panics.rs

@@ -13,7 +13,8 @@ fn main() {
     // These run in docker containers on CI where they can't re-exec the test,
     // so just skip these for CI. No other reason this can't run on those
     // platforms though.
-    if cfg!(unix) && (cfg!(target_arch = "arm") || cfg!(target_arch = "aarch64")) {
+    // Miri does not have support for re-execing a file
+    if cfg!(unix) && (cfg!(target_arch = "arm") || cfg!(target_arch = "aarch64")) || cfg!(miri) {
         println!("test result: ok");
         return;
     }

tests/smoke.rs

@@ -2,7 +2,7 @@ use backtrace::Frame;
 use std::thread;
 
 // Reflects the conditional compilation logic at end of src/symbolize/mod.rs
-static NOOP: bool = cfg!(miri);
+static NOOP: bool = false;
 static DBGHELP: bool = !NOOP
     && cfg!(all(
         windows,
@@ -31,6 +31,7 @@ static GIMLI_SYMBOLIZE: bool = !NOOP
         not(target_vendor = "uwp"),
         not(target_os = "emscripten"),
     ));
+static MIRI_SYMBOLIZE: bool = cfg!(miri);
 
 #[test]
 // FIXME: shouldn't ignore this test on i686-msvc, unsure why it's failing
@@ -158,8 +159,8 @@ fn smoke_test_frames() {
         }
 
         let mut resolved = 0;
-        let can_resolve = LIBBACKTRACE || GIMLI_SYMBOLIZE;
-        let can_resolve_cols = GIMLI_SYMBOLIZE;
+        let can_resolve = LIBBACKTRACE || GIMLI_SYMBOLIZE || MIRI_SYMBOLIZE;
+        let can_resolve_cols = GIMLI_SYMBOLIZE || MIRI_SYMBOLIZE;
 
         let mut name = None;
         let mut addr = None;