From 73e5a1eae6b53db7119c14be29aba6999a5e3728 Mon Sep 17 00:00:00 2001 From: Ridwan Abdilahi Date: Wed, 7 Sep 2022 17:22:14 -0700 Subject: [PATCH] Add Natvis definitions and tests for SmallVec type with and without the `union` crate feature enabled. Unify Natvis definitions into a single Natvis file. --- .github/workflows/main.yml | 23 +++++-- Cargo.toml | 17 +++++ debug_metadata/README.md | 111 +++++++++++++++++++++++++++++++++ debug_metadata/smallvec.natvis | 35 +++++++++++ scripts/run_miri.sh | 3 + src/lib.rs | 5 ++ tests/debugger_visualizer.rs | 68 ++++++++++++++++++++ 7 files changed, 257 insertions(+), 5 deletions(-) create mode 100644 debug_metadata/README.md create mode 100644 debug_metadata/smallvec.natvis create mode 100644 tests/debugger_visualizer.rs diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml index fec61b3..97ccab9 100644 --- a/.github/workflows/main.yml +++ b/.github/workflows/main.yml @@ -7,9 +7,8 @@ on: workflow_dispatch: jobs: - linux-ci: - name: Linux - runs-on: ubuntu-latest + ci: + name: Build/Test strategy: matrix: toolchain: ["stable", "beta", "nightly", "1.36.0"] @@ -20,10 +19,16 @@ jobs: - toolchain: beta env: DO_FUZZ: 1 + - os: windows-latest + toolchain: nightly + + runs-on: ${{ matrix.os }} + steps: - uses: actions/checkout@v2 - name: Install packages + if: matrix.os == 'ubuntu-latest' run: sudo apt-get install -y binutils-dev libunwind8-dev libcurl4-openssl-dev libelf-dev libdw-dev cmake gcc libiberty-dev - name: Install toolchain @@ -50,6 +55,14 @@ jobs: if: matrix.toolchain == 'beta' run: cargo test --verbose --features union + - name: Cargo test w/ debugger_visualizer + if: matrix.toolchain == 'nightly' + run: cargo test --test debugger_visualizer --verbose --features debugger_visualizer -- --test-threads=1 + + - name: Cargo test w/ debugger_visualizer and union + if: matrix.toolchain == 'nightly' + run: cargo test --test debugger_visualizer --verbose --features 'debugger_visualizer,union' -- --test-threads=1 + - name: Cargo test all features if: matrix.toolchain == 'nightly' run: cargo test --verbose --all-features @@ -59,7 +72,7 @@ jobs: run: cargo bench --verbose bench - name: miri - if: matrix.toolchain == 'nightly' + if: matrix.toolchain == 'nightly' && matrix.os == 'ubuntu-latest' run: bash ./scripts/run_miri.sh env: MIRIFLAGS: '-Zmiri-tag-raw-pointers' @@ -73,7 +86,7 @@ jobs: name: homu build finished runs-on: ubuntu-latest needs: - - "linux-ci" + - "ci" steps: - name: Mark the job as successful diff --git a/Cargo.toml b/Cargo.toml index a8a0c8d..5f07ea6 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -19,13 +19,30 @@ union = [] specialization = [] may_dangle = [] +# UNSTABLE FEATURES (requires Rust nightly) +# Enable to use the #[debugger_visualizer] attribute. +debugger_visualizer = [] + [dependencies] serde = { version = "1", optional = true, default-features = false } arbitrary = { version = "1", optional = true } [dev_dependencies] bincode = "1.0.1" +debugger_test = "0.1.0" +debugger_test_parser = "0.1.0" [package.metadata.docs.rs] all-features = true rustdoc-args = ["--cfg", "docsrs"] + +[[test]] +name = "debugger_visualizer" +path = "tests/debugger_visualizer.rs" +required-features = ["debugger_visualizer"] +# Do not run these tests by default. These tests need to +# be run with the additional rustc flag `--test-threads=1` +# since each test causes a debugger to attach to the current +# test process. If multiple debuggers try to attach at the same +# time, the test will fail. +test = false diff --git a/debug_metadata/README.md b/debug_metadata/README.md new file mode 100644 index 0000000..1375008 --- /dev/null +++ b/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 `\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 `smallvec` +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 `smallvec` 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 `smallvec` 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 `smallvec` crate via `debug_metadata/smallvec.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 +``` diff --git a/debug_metadata/smallvec.natvis b/debug_metadata/smallvec.natvis new file mode 100644 index 0000000..b38d47c --- /dev/null +++ b/debug_metadata/smallvec.natvis @@ -0,0 +1,35 @@ + + + + + + + {{ len={len()} }} + + is_inline() ? $T2 : capacity + len() + + + len() + data_ptr() + + + + + + + + + + {{ len={len()} }} + + is_inline() ? $T2 : capacity + len() + + + len() + data_ptr() + + + + \ No newline at end of file diff --git a/scripts/run_miri.sh b/scripts/run_miri.sh index 817928a..010ceb0 100644 --- a/scripts/run_miri.sh +++ b/scripts/run_miri.sh @@ -11,6 +11,7 @@ cargo clean MIRI_NIGHTLY=nightly-$(curl -s https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu/miri) echo "Installing latest nightly with Miri: $MIRI_NIGHTLY" +rustup override unset rustup default "$MIRI_NIGHTLY" rustup component add miri @@ -19,3 +20,5 @@ cargo miri setup cargo miri test --verbose cargo miri test --verbose --features union cargo miri test --verbose --all-features + +rustup override set nightly diff --git a/src/lib.rs b/src/lib.rs index 921347a..69d0627 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -81,6 +81,11 @@ #![cfg_attr(feature = "specialization", allow(incomplete_features))] #![cfg_attr(feature = "specialization", feature(specialization))] #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))] +#![cfg_attr( + feature = "debugger_visualizer", + feature(debugger_visualizer), + debugger_visualizer(natvis_file = "../debug_metadata/smallvec.natvis") +)] #![deny(missing_docs)] #[doc(hidden)] diff --git a/tests/debugger_visualizer.rs b/tests/debugger_visualizer.rs new file mode 100644 index 0000000..210f539 --- /dev/null +++ b/tests/debugger_visualizer.rs @@ -0,0 +1,68 @@ +use debugger_test::debugger_test; +use smallvec::{smallvec, SmallVec}; + +#[inline(never)] +fn __break() {} + +#[debugger_test( + debugger = "cdb", + commands = r#" +.nvlist +dx sv + +g + +dx sv + +g + +dx sv +"#, + expected_statements = r#" +sv : { len=0x2 } [Type: smallvec::SmallVec >] + [] [Type: smallvec::SmallVec >] + [capacity] : 4 + [len] : 0x2 [Type: unsigned __int64] + [0] : 1 [Type: int] + [1] : 2 [Type: int] + +sv : { len=0x5 } [Type: smallvec::SmallVec >] + [] [Type: smallvec::SmallVec >] + [capacity] : 0x8 [Type: unsigned __int64] + [len] : 0x5 [Type: unsigned __int64] + [0] : 5 [Type: int] + [1] : 2 [Type: int] + [2] : 3 [Type: int] + [3] : 4 [Type: int] + [4] : 5 [Type: int] + +sv : { len=0x5 } [Type: smallvec::SmallVec >] + [] [Type: smallvec::SmallVec >] + [capacity] : 0x8 [Type: unsigned __int64] + [len] : 0x5 [Type: unsigned __int64] + [0] : 2 [Type: int] + [1] : 3 [Type: int] + [2] : 4 [Type: int] + [3] : 5 [Type: int] + [4] : 5 [Type: int] +"# +)] +#[inline(never)] +fn test_debugger_visualizer() { + // This SmallVec can hold up to 4 items on the stack: + let mut sv: SmallVec<[i32; 4]> = smallvec![1, 2]; + __break(); + + // Overfill the SmallVec to move its contents to the heap + for i in 3..6 { + sv.push(i); + } + + // Update the contents of the first value of the SmallVec. + sv[0] = sv[1] + sv[2]; + __break(); + + // Sort the SmallVec in place. + sv.sort(); + __break(); +}