Implement --check-cfg option (RFC 3013)

Co-authored-by: Urgau <lolo.branstett@numericable.fr>
Co-authored-by: Marcelina Kościelnicka <mwk@0x04.net>

19 files changed, 106 insertions, 1 deletions

diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 1f14a333c00..5d2f774f8cf 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -250,6 +250,7 @@ crate fn create_config(
     interface::Config {
         opts: sessopts,
         crate_cfg: interface::parse_cfgspecs(cfgs),
+        crate_check_cfg: interface::parse_check_cfg(vec![]),
         input,
         input_path: cpath,
         output_file: None,
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 6c55721c0dd..6f398c17683 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -91,6 +91,7 @@ crate fn run(options: RustdocOptions) -> Result<(), ErrorReported> {
     let config = interface::Config {
         opts: sessopts,
         crate_cfg: interface::parse_cfgspecs(cfgs),
+        crate_check_cfg: interface::parse_check_cfg(vec![]),
         input,
         input_path: None,
         output_file: None,
diff --git a/src/test/run-make-fulldeps/issue-19371/foo.rs b/src/test/run-make-fulldeps/issue-19371/foo.rs
index 4acabbb70ed..ec711eb4e48 100644
--- a/src/test/run-make-fulldeps/issue-19371/foo.rs
+++ b/src/test/run-make-fulldeps/issue-19371/foo.rs
@@ -49,6 +49,7 @@ fn compile(code: String, output: PathBuf, sysroot: PathBuf) {
     let config = interface::Config {
         opts,
         crate_cfg: Default::default(),
+        crate_check_cfg: Default::default(),
         input,
         input_path: None,
         output_file: Some(output),
diff --git a/src/test/ui/check-cfg/empty-names.rs b/src/test/ui/check-cfg/empty-names.rs
new file mode 100644
index 00000000000..046ff0364e2
--- /dev/null
+++ b/src/test/ui/check-cfg/empty-names.rs
@@ -0,0 +1,10 @@
+// Check warning for unexpected cfg
+//
+// check-pass
+// compile-flags: --check-cfg=names() -Z unstable-options
+
+#[cfg(unknown_key = "value")]
+//~^ WARNING unexpected `cfg` condition name
+pub fn f() {}
+
+fn main() {}
diff --git a/src/test/ui/check-cfg/empty-names.stderr b/src/test/ui/check-cfg/empty-names.stderr
new file mode 100644
index 00000000000..f926d1133cc
--- /dev/null
+++ b/src/test/ui/check-cfg/empty-names.stderr
@@ -0,0 +1,10 @@
+warning: unexpected `cfg` condition name
+  --> $DIR/empty-names.rs:6:7
+   |
+LL | #[cfg(unknown_key = "value")]
+   |       ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unexpected_cfgs)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/src/test/ui/check-cfg/empty-values.rs b/src/test/ui/check-cfg/empty-values.rs
new file mode 100644
index 00000000000..38ef9e51c7a
--- /dev/null
+++ b/src/test/ui/check-cfg/empty-values.rs
@@ -0,0 +1,6 @@
+// Check that a an empty values() is rejected
+//
+// check-fail
+// compile-flags: --check-cfg=values() -Z unstable-options
+
+fn main() {}
diff --git a/src/test/ui/check-cfg/empty-values.stderr b/src/test/ui/check-cfg/empty-values.stderr
new file mode 100644
index 00000000000..106d5b7b47f
--- /dev/null
+++ b/src/test/ui/check-cfg/empty-values.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `values()` (expected `names(name1, name2, ... nameN)` or `values(name, "value1", "value2", ... "valueN")`)
+
diff --git a/src/test/ui/check-cfg/invalid-arguments.anything_else.stderr b/src/test/ui/check-cfg/invalid-arguments.anything_else.stderr
new file mode 100644
index 00000000000..850924d993a
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-arguments.anything_else.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `anything_else(...)` (expected `names(name1, name2, ... nameN)` or `values(name, "value1", "value2", ... "valueN")`)
+
diff --git a/src/test/ui/check-cfg/invalid-arguments.names_simple_ident.stderr b/src/test/ui/check-cfg/invalid-arguments.names_simple_ident.stderr
new file mode 100644
index 00000000000..bdfbc3d54a2
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-arguments.names_simple_ident.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `names("NOT_IDENT")` (`names()` arguments must be simple identifers)
+
diff --git a/src/test/ui/check-cfg/invalid-arguments.rs b/src/test/ui/check-cfg/invalid-arguments.rs
new file mode 100644
index 00000000000..5090ce3e845
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-arguments.rs
@@ -0,0 +1,10 @@
+// Check that invalid --check-cfg are rejected
+//
+// check-fail
+// revisions: anything_else names_simple_ident values_simple_ident values_string_literals
+// [anything_else]compile-flags: -Z unstable-options --check-cfg=anything_else(...)
+// [names_simple_ident]compile-flags: -Z unstable-options --check-cfg=names("NOT_IDENT")
+// [values_simple_ident]compile-flags: -Z unstable-options --check-cfg=values("NOT_IDENT")
+// [values_string_literals]compile-flags: -Z unstable-options --check-cfg=values(test,12)
+
+fn main() {}
diff --git a/src/test/ui/check-cfg/invalid-arguments.values_simple_ident.stderr b/src/test/ui/check-cfg/invalid-arguments.values_simple_ident.stderr
new file mode 100644
index 00000000000..b25882baaf3
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-arguments.values_simple_ident.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `values("NOT_IDENT")` (`values()` first argument must be a simple identifer)
+
diff --git a/src/test/ui/check-cfg/invalid-arguments.values_string_literals.stderr b/src/test/ui/check-cfg/invalid-arguments.values_string_literals.stderr
new file mode 100644
index 00000000000..5853b4741a6
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-arguments.values_string_literals.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `values(test,12)` (`values()` arguments must be string literals)
+
diff --git a/src/test/ui/check-cfg/invalid-cfg-name.rs b/src/test/ui/check-cfg/invalid-cfg-name.rs
new file mode 100644
index 00000000000..8499d3d4448
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-cfg-name.rs
@@ -0,0 +1,14 @@
+// Check warning for invalid configuration name
+//
+// edition:2018
+// check-pass
+// compile-flags: --check-cfg=names() -Z unstable-options
+
+#[cfg(widnows)]
+//~^ WARNING unexpected `cfg` condition name
+pub fn f() {}
+
+#[cfg(windows)]
+pub fn g() {}
+
+pub fn main() {}
diff --git a/src/test/ui/check-cfg/invalid-cfg-name.stderr b/src/test/ui/check-cfg/invalid-cfg-name.stderr
new file mode 100644
index 00000000000..2587685afa0
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-cfg-name.stderr
@@ -0,0 +1,10 @@
+warning: unexpected `cfg` condition name
+  --> $DIR/invalid-cfg-name.rs:7:7
+   |
+LL | #[cfg(widnows)]
+   |       ^^^^^^^
+   |
+   = note: `#[warn(unexpected_cfgs)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/src/test/ui/check-cfg/invalid-cfg-value.rs b/src/test/ui/check-cfg/invalid-cfg-value.rs
new file mode 100644
index 00000000000..a60095a5aae
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-cfg-value.rs
@@ -0,0 +1,17 @@
+// Check warning for invalid configuration value
+//
+// edition:2018
+// check-pass
+// compile-flags: --check-cfg=values(feature,"serde","full") --cfg=feature="rand" -Z unstable-options
+
+#[cfg(feature = "sedre")]
+//~^ WARNING unexpected `cfg` condition value
+pub fn f() {}
+
+#[cfg(feature = "serde")]
+pub fn g() {}
+
+#[cfg(feature = "rand")]
+pub fn h() {}
+
+pub fn main() {}
diff --git a/src/test/ui/check-cfg/invalid-cfg-value.stderr b/src/test/ui/check-cfg/invalid-cfg-value.stderr
new file mode 100644
index 00000000000..c591d8474a2
--- /dev/null
+++ b/src/test/ui/check-cfg/invalid-cfg-value.stderr
@@ -0,0 +1,10 @@
+warning: unexpected `cfg` condition value
+  --> $DIR/invalid-cfg-value.rs:7:7
+   |
+LL | #[cfg(feature = "sedre")]
+   |       ^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unexpected_cfgs)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/src/test/ui/feature-gates/feature-gate-check-cfg.rs b/src/test/ui/feature-gates/feature-gate-check-cfg.rs
new file mode 100644
index 00000000000..4012a3b04b5
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-check-cfg.rs
@@ -0,0 +1,3 @@
+// compile-flags: --check-cfg "names()"
+
+fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-check-cfg.stderr b/src/test/ui/feature-gates/feature-gate-check-cfg.stderr
new file mode 100644
index 00000000000..9b27c2bc058
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-check-cfg.stderr
@@ -0,0 +1,2 @@
+error: the `-Z unstable-options` flag must also be passed to enable the flag `check-cfg`
+
diff --git a/src/tools/tidy/src/ui_tests.rs b/src/tools/tidy/src/ui_tests.rs
index 203e33e8b1f..95847dcd46b 100644
--- a/src/tools/tidy/src/ui_tests.rs
+++ b/src/tools/tidy/src/ui_tests.rs
@@ -7,7 +7,7 @@ use std::path::Path;
 
 const ENTRY_LIMIT: usize = 1000;
 // FIXME: The following limits should be reduced eventually.
-const ROOT_ENTRY_LIMIT: usize = 982;
+const ROOT_ENTRY_LIMIT: usize = 983;
 const ISSUES_ENTRY_LIMIT: usize = 2310;
 
 fn check_entries(path: &Path, bad: &mut bool) {