[tools] initial work on target determinator

Introduce an initial version of a target determinator: a way to figure
out which packages have changed in a repository.

Author: sunshowers

.github/workflows/ci.yml

@@ -65,17 +65,16 @@ jobs:
         with:
           command: build
           args: --all-targets --package target-spec
-      # Build all packages we care about one by one to ensure feature unification
-      # doesn't happen.
-      # Build all targets to ensure examples are built as well.
       - name: Build and test guppy
         uses: actions-rs/cargo@v1
         with:
           command: build
           args: --all-targets --package guppy
-      # Build all packages we care about one by one to ensure feature unification
-      # doesn't happen.
-      # Build all targets to ensure examples are built as well.
+      - name: Build and test determinator
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --all-targets --package determinator
       - name: Build and test cargo-guppy
         uses: actions-rs/cargo@v1
         with:

Cargo.lock

@@ -10,4 +10,5 @@ members = [
     "internal-tools/fixture-manager",
     "internal-tools/proptest-ext",
     "target-spec",
+    "tools/determinator",
 ]

Cargo.toml

@@ -0,0 +1,16 @@
+# This file lists out determinator package rules that can be used in tests.
+
+# This path rule means guppy is triggered, which causes guppy-benchmark to be changed, which causes
+# everything to change.
+[[path-rule]]
+globs = ["**/fake-trigger"]
+mark-changed = ["proptest-ext"]
+
+[[package-rule]]
+on-affected = ["fixtures"]
+mark-changed = ["guppy-cmdlib"]
+
+[[package-rule]]
+on-affected = ["guppy-benchmarks"]
+mark-changed = "all"
+

fixtures/guppy/package_rules.toml

@@ -0,0 +1,29 @@
+# This file lists out determinator path rules that can be used in tests.
+
+[[path-rule]]
+# Ignore README files.
+globs = ["**/README.md", "**/README.tpl"]
+mark-changed = []
+post-rule = "skip"
+
+[[path-rule]]
+# This is a test rule to ensure that marking packages changed works.
+globs = ["CODE_OF_CONDUCT.md", "CONTRIBUTING.md"]
+mark-changed = ["cargo-guppy"]
+post-rule = "fallthrough"
+
+[[path-rule]]
+# Ensure fallthrough works from above.
+globs = ["CODE_OF_CONDUCT.md"]
+mark-changed = ["guppy"]
+
+[[path-rule]]
+# Test for skip-rules.
+globs = ["**/foo"]
+mark-changed = ["cargo-compare"]
+post-rule = "skip-rules"
+
+[[path-rule]]
+# The above rule should mean this never gets applied.
+globs = ["**/foo"]
+mark-changed = ["target-spec"]

fixtures/guppy/path_rules.toml

@@ -7,7 +7,7 @@ include-dev = false
 proc-macros-on-target = false
 
 [metadata.target-platform]
-triple = 'x86_64-fortanix-unknown-sgx'
+triple = 'x86_64-apple-tvos'
 target-features = 'all'
 flags = ['abc']
 
@@ -688,6 +688,13 @@ crates-io = true
 status = 'transitive'
 features = []
 
+[[target-package]]
+name = 'openssl-probe'
+version = '0.1.2'
+crates-io = true
+status = 'transitive'
+features = []
+
 [[target-package]]
 name = 'openssl-sys'
 version = '0.9.58'
@@ -891,6 +898,13 @@ crates-io = true
 status = 'transitive'
 features = []
 
+[[target-package]]
+name = 'termios'
+version = '0.3.2'
+crates-io = true
+status = 'transitive'
+features = []
+
 [[target-package]]
 name = 'textwrap'
 version = '0.11.0'

fixtures/guppy/summaries/metadata_guppy_78cb7e8-1.toml

@@ -7,7 +7,7 @@ include-dev = false
 proc-macros-on-target = true
 
 [metadata.target-platform]
-triple = 'aarch64-apple-ios'
+triple = 'aarch64-apple-darwin'
 target-features = 'all'
 
 [[target-package]]

fixtures/guppy/summaries/metadata_guppy_78cb7e8-4.toml

@@ -7,7 +7,7 @@ include-dev = true
 proc-macros-on-target = false
 
 [metadata.host-platform]
-triple = 'mips64-unknown-linux-gnuabi64'
+triple = 'mips64-unknown-linux-muslabi64'
 target-features = ['sse4.2', 'ssse3', 'xsaves']
 flags = ['cargo_web']