Add Natvis visualizations for core indexmap types

.github/workflows/ci.yml

@@ -12,9 +12,9 @@ env:
 
 jobs:
   tests:
-    runs-on: ubuntu-latest
     strategy:
       matrix:
+        os: [ubuntu-latest]
         include:
           - rust: 1.56.0 # MSRV
             features:
@@ -30,6 +30,13 @@ jobs:
             features:
           - rust: nightly
             bench: test build benchmarks
+          - rust: nightly
+            features: debugger_visualizer
+          - rust: nightly
+            features: debugger_visualizer
+            os: windows-latest
+
+    runs-on: ${{ matrix.os }}
 
     steps:
       - uses: actions/checkout@v3
@@ -46,6 +53,10 @@ jobs:
         if: matrix.features == 'serde'
         run: |
           cargo test --verbose -p test-serde
+      - name: Tests (debugger_visualizer)
+        if: matrix.features == 'debugger_visualizer'
+        run: |
+          cargo test --verbose --test debugger_visualizer --features "${{ matrix.features }}" -- --test-threads=1
       - name: Test run benchmarks
         if: matrix.bench != ''
         run: cargo test -v --benches

Cargo.toml

@@ -35,6 +35,8 @@ fnv = "1.0"
 lazy_static = "1.3"
 fxhash = "0.2.1"
 serde_derive = "1.0"
+debugger_test = "0.1"
+debugger_test_parser = "0.1"
 
 [features]
 default = ["std"]
@@ -43,6 +45,10 @@ std = []
 # for testing only, of course
 test_debug = []
 
+# UNSTABLE FEATURES (requires Rust nightly)
+# Enable to use the #[debugger_visualizer] attribute.
+debugger_visualizer = []
+
 [profile.bench]
 debug = true
 
@@ -55,3 +61,9 @@ features = ["serde", "rayon"]
 
 [workspace]
 members = ["test-nostd", "test-serde"]
+
+[[test]]
+path = "tests/debugger_visualizer.rs"
+name = "debugger_visualizer"
+required-features = ["debugger_visualizer"]
+test = false

debug_metadata/README.md

@@ -0,0 +1,111 @@
+## Debugger Visualizers
+
+Many languages and debuggers enable developers to control how a type is
+displayed in a debugger. These are called "debugger visualizations" or "debugger
+views".
+
+The Windows debuggers (WinDbg\CDB) support defining custom debugger visualizations using
+the `Natvis` framework. To use Natvis, developers write XML documents using the natvis
+schema that describe how debugger types should be displayed with the `.natvis` extension.
+(See: https://docs.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects?view=vs-2019)
+The Natvis files provide patterns which match type names a description of how to display
+those types.
+
+The Natvis schema can be found either online (See: https://code.visualstudio.com/docs/cpp/natvis#_schema)
+or locally at `<VS Installation Folder>\Xml\Schemas\1033\natvis.xsd`.
+
+The GNU debugger (GDB) supports defining custom debugger views using Pretty Printers.
+Pretty printers are written as python scripts that describe how a type should be displayed
+when loaded up in GDB/LLDB. (See: https://sourceware.org/gdb/onlinedocs/gdb/Pretty-Printing.html#Pretty-Printing)
+The pretty printers provide patterns, which match type names, and for matching
+types, descibe how to display those types. (For writing a pretty printer, see: https://sourceware.org/gdb/onlinedocs/gdb/Writing-a-Pretty_002dPrinter.html#Writing-a-Pretty_002dPrinter).
+
+### Embedding Visualizers
+
+Through the use of the currently unstable `#[debugger_visualizer]` attribute, the `indexmap`
+crate can embed debugger visualizers into the crate metadata.
+
+Currently the two types of visualizers supported are Natvis and Pretty printers.
+
+For Natvis files, when linking an executable with a crate that includes Natvis files,
+the MSVC linker will embed the contents of all Natvis files into the generated `PDB`.
+
+For pretty printers, the compiler will encode the contents of the pretty printer
+in the `.debug_gdb_scripts` section of the `ELF` generated.
+
+### Testing Visualizers
+
+The `indexmap` crate supports testing debugger visualizers defined for this crate. The entry point for
+these tests are `tests/debugger_visualizer.rs`. These tests are defined using the `debugger_test` and
+`debugger_test_parser` crates. The `debugger_test` crate is a proc macro crate which defines a
+single proc macro attribute, `#[debugger_test]`. For more detailed information about this crate,
+see https://crates.io/crates/debugger_test. The CI pipeline for the `indexmap` crate has been updated
+to run the debugger visualizer tests to ensure debugger visualizers do not become broken/stale.
+
+The `#[debugger_test]` proc macro attribute may only be used on test functions and will run the
+function under the debugger specified by the `debugger` meta item.
+
+This proc macro attribute has 3 required values:
+
+1. The first required meta item, `debugger`, takes a string value which specifies the debugger to launch.
+2. The second required meta item, `commands`, takes a string of new line (`\n`) separated list of debugger
+commands to run.
+3. The third required meta item, `expected_statements`, takes a string of new line (`\n`) separated list of
+statements that must exist in the debugger output. Pattern matching through regular expressions is also
+supported by using the `pattern:` prefix for each expected statement.
+
+#### Example:
+
+```rust
+#[debugger_test(
+    debugger = "cdb",
+    commands = "command1\ncommand2\ncommand3",
+    expected_statements = "statement1\nstatement2\nstatement3")]
+fn test() {
+
+}
+```
+
+Using a multiline string is also supported, with a single debugger command/expected statement per line:
+
+```rust
+#[debugger_test(
+    debugger = "cdb",
+    commands = "
+command1
+command2
+command3",
+    expected_statements = "
+statement1
+pattern:statement[0-9]+
+statement3")]
+fn test() {
+
+}
+```
+
+In the example above, the second expected statement uses pattern matching through a regular expression
+by using the `pattern:` prefix.
+
+#### Testing Locally
+
+Currently, only Natvis visualizations have been defined for the `indexmap` crate via `debug_metadata/indexmap.natvis`,
+which means the `tests/debugger_visualizer.rs` tests need to be run on Windows using the `*-pc-windows-msvc` targets.
+To run these tests locally, first ensure the debugging tools for Windows are installed or install them following
+the steps listed here, [Debugging Tools for Windows](https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/).
+Once the debugging tools have been installed, the tests can be run in the same manner as they are in the CI
+pipeline.
+
+#### Note
+
+When running the debugger visualizer tests, `tests/debugger_visualizer.rs`, they need to be run consecutively
+and not in parallel. This can be achieved by passing the flag `--test-threads=1` to rustc. This is due to
+how the debugger tests are run. Each test marked with the `#[debugger_test]` attribute launches a debugger
+and attaches it to the current test process. If tests are running in parallel, the test will try to attach
+a debugger to the current process which may already have a debugger attached causing the test to fail.
+
+For example:
+
+```
+cargo test --test debugger_visualizer --features debugger_visualizer -- --test-threads=1
+```

debug_metadata/indexmap.natvis

@@ -0,0 +1,29 @@
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+  <Type Name="indexmap::set::IndexSet&lt;*,*&gt;">
+    <DisplayString>{{ len={map.core.entries.len} }}</DisplayString>
+    <Expand>
+      <ExpandedItem>map</ExpandedItem>
+    </Expand>
+  </Type>
+  <Type Name="indexmap::map::IndexMap&lt;*,*,*&gt;">
+    <DisplayString>{{ len={core.entries.len} }}</DisplayString>
+    <Expand>
+      <ExpandedItem>core.entries</ExpandedItem>
+    </Expand>
+  </Type>
+  <Type Name="indexmap::Bucket&lt;*,tuple$&lt;&gt;&gt;">
+    <DisplayString>{key}</DisplayString>
+    <Expand>
+      <Item Name="[key]">key</Item>
+      <Item Name="[hash]">hash.__0,d</Item>
+    </Expand>
+  </Type>
+  <Type Name="indexmap::Bucket&lt;*,*&gt;">
+    <DisplayString>{{ key={key}, value={value} }}</DisplayString>
+    <Expand>
+      <Item Name="[key]">key</Item>
+      <Item Name="[value]">value</Item>
+      <Item Name="[hash]">hash.__0,d</Item>
+    </Expand>
+  </Type>
+</AutoVisualizer>

src/lib.rs

@@ -3,6 +3,11 @@
 #![warn(rust_2018_idioms)]
 #![doc(html_root_url = "https://docs.rs/indexmap/1/")]
 #![no_std]
+#![cfg_attr(
+    feature = "debugger_visualizer",
+    feature(debugger_visualizer),
+    debugger_visualizer(natvis_file = "../debug_metadata/indexmap.natvis")
+)]
 
 //! [`IndexMap`] is a hash table where the iteration order of the key-value
 //! pairs is independent of the hash values of the keys.

tests/debugger_visualizer.rs

@@ -0,0 +1,89 @@
+use debugger_test::debugger_test;
+use indexmap::IndexMap;
+use indexmap::IndexSet;
+
+#[inline(never)]
+fn __break() {}
+
+#[debugger_test(
+    debugger = "cdb",
+    commands = r#"
+.nvlist
+dx set
+dx map
+"#,
+    expected_statements = r#"
+set              : { len=0x19 } [Type: indexmap::set::IndexSet<char,std::collections::hash::map::RandomState>]
+    [len]            : 0x19 [Type: unsigned __int64]
+    [capacity]       : 0x1c [Type: unsigned __int64]
+    [0]              : 0x74 't' [Type: indexmap::Bucket<char,tuple$<> >]
+    [1]              : 0x68 'h' [Type: indexmap::Bucket<char,tuple$<> >]
+    [2]              : 0x65 'e' [Type: indexmap::Bucket<char,tuple$<> >]
+    [3]              : 0x20 ' ' [Type: indexmap::Bucket<char,tuple$<> >]
+    [4]              : 0x71 'q' [Type: indexmap::Bucket<char,tuple$<> >]
+    [5]              : 0x75 'u' [Type: indexmap::Bucket<char,tuple$<> >]
+    [6]              : 0x69 'i' [Type: indexmap::Bucket<char,tuple$<> >]
+    [7]              : 0x63 'c' [Type: indexmap::Bucket<char,tuple$<> >]
+    [8]              : 0x6b 'k' [Type: indexmap::Bucket<char,tuple$<> >]
+    [9]              : 0x72 'r' [Type: indexmap::Bucket<char,tuple$<> >]
+    [10]             : 0x6f 'o' [Type: indexmap::Bucket<char,tuple$<> >]
+    [11]             : 0x77 'w' [Type: indexmap::Bucket<char,tuple$<> >]
+    [12]             : 0x6e 'n' [Type: indexmap::Bucket<char,tuple$<> >]
+    [13]             : 0x66 'f' [Type: indexmap::Bucket<char,tuple$<> >]
+    [14]             : 0x78 'x' [Type: indexmap::Bucket<char,tuple$<> >]
+    [15]             : 0x6a 'j' [Type: indexmap::Bucket<char,tuple$<> >]
+    [16]             : 0x6d 'm' [Type: indexmap::Bucket<char,tuple$<> >]
+    [17]             : 0x70 'p' [Type: indexmap::Bucket<char,tuple$<> >]
+    [18]             : 0x64 'd' [Type: indexmap::Bucket<char,tuple$<> >]
+    [19]             : 0x76 'v' [Type: indexmap::Bucket<char,tuple$<> >]
+    [20]             : 0x6c 'l' [Type: indexmap::Bucket<char,tuple$<> >]
+    [21]             : 0x61 'a' [Type: indexmap::Bucket<char,tuple$<> >]
+    [22]             : 0x7a 'z' [Type: indexmap::Bucket<char,tuple$<> >]
+    [23]             : 0x79 'y' [Type: indexmap::Bucket<char,tuple$<> >]
+    [24]             : 0x67 'g' [Type: indexmap::Bucket<char,tuple$<> >]
+
+map              : { len=0x19 } [Type: indexmap::map::IndexMap<char,i32,std::collections::hash::map::RandomState>]
+    [len]            : 0x19 [Type: unsigned __int64]
+    [capacity]       : 0x1c [Type: unsigned __int64]
+    [0]              : { key=0x74 't', value=2 } [Type: indexmap::Bucket<char,i32>]
+    [1]              : { key=0x68 'h', value=2 } [Type: indexmap::Bucket<char,i32>]
+    [2]              : { key=0x65 'e', value=4 } [Type: indexmap::Bucket<char,i32>]
+    [3]              : { key=0x20 ' ', value=8 } [Type: indexmap::Bucket<char,i32>]
+    [4]              : { key=0x71 'q', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [5]              : { key=0x75 'u', value=2 } [Type: indexmap::Bucket<char,i32>]
+    [6]              : { key=0x69 'i', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [7]              : { key=0x63 'c', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [8]              : { key=0x6b 'k', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [9]              : { key=0x67 'g', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [10]             : { key=0x72 'r', value=2 } [Type: indexmap::Bucket<char,i32>]
+    [11]             : { key=0x6f 'o', value=4 } [Type: indexmap::Bucket<char,i32>]
+    [12]             : { key=0x77 'w', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [13]             : { key=0x6e 'n', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [14]             : { key=0x66 'f', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [15]             : { key=0x78 'x', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [16]             : { key=0x6a 'j', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [17]             : { key=0x6d 'm', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [18]             : { key=0x70 'p', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [19]             : { key=0x64 'd', value=2 } [Type: indexmap::Bucket<char,i32>]
+    [20]             : { key=0x76 'v', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [21]             : { key=0x6c 'l', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [22]             : { key=0x61 'a', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [23]             : { key=0x7a 'z', value=1 } [Type: indexmap::Bucket<char,i32>]
+    [24]             : { key=0x79 'y', value=1 } [Type: indexmap::Bucket<char,i32>]
+"#
+)]
+fn test_debugger_visualizer() {
+    let mut set = IndexSet::new();
+    let mut map = IndexMap::new();
+
+    for ch in "the quick brown fox jumped over the lazy dog".chars() {
+        set.insert(ch);
+        *map.entry(ch).or_insert(0) += 1;
+    }
+
+    let b = 'b';
+    assert!(set.shift_remove(&b));
+    assert_eq!(Some(1), map.remove(&b));
+
+    __break();
+}