Add a run-make test for `rustc --help` and similar

5 files changed, 188 insertions, 0 deletions

diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index 368b98c9f0d..5765cb97a7e 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -41,6 +41,7 @@ pub use libc;
 pub use object;
 pub use regex;
 pub use serde_json;
+pub use similar;
 pub use wasmparser;
 // tidy-alphabetical-end
 
diff --git a/tests/run-make/rustc-help/help-v.diff b/tests/run-make/rustc-help/help-v.diff
new file mode 100644
index 00000000000..22c5dd81bdb
--- /dev/null
+++ b/tests/run-make/rustc-help/help-v.diff
@@ -0,0 +1,29 @@
+@@ -51,10 +51,27 @@
+                         Set a codegen option
+     -V, --version       Print version info and exit
+     -v, --verbose       Use verbose output
++        --extern NAME[=PATH]
++                        Specify where an external rust library is located
++        --sysroot PATH  Override the system root
++        --error-format human|json|short
++                        How errors and other messages are produced
++        --json CONFIG   Configure the JSON output of the compiler
++        --color auto|always|never
++                        Configure coloring of output:
++                        auto = colorize, if output goes to a tty (default);
++                        always = always colorize output;
++                        never = never colorize output
++        --diagnostic-width WIDTH
++                        Inform rustc of the width of the output so that
++                        diagnostics can be truncated to fit
++        --remap-path-prefix FROM=TO
++                        Remap source names in all output (compiler messages
++                        and output files)
++    @path               Read newline separated options from `path`
+ 
+ Additional help:
+     -C help             Print codegen options
+     -W help             Print 'lint' options and default settings
+     -Z help             Print unstable compiler options
+-    --help -v           Print the full set of options rustc accepts
+ 
diff --git a/tests/run-make/rustc-help/help-v.stdout b/tests/run-make/rustc-help/help-v.stdout
new file mode 100644
index 00000000000..dbd67b57df2
--- /dev/null
+++ b/tests/run-make/rustc-help/help-v.stdout
@@ -0,0 +1,77 @@
+Usage: rustc [OPTIONS] INPUT
+
+Options:
+    -h, --help          Display this message
+        --cfg SPEC      Configure the compilation environment.
+                        SPEC supports the syntax `NAME[="VALUE"]`.
+        --check-cfg SPEC
+                        Provide list of expected cfgs for checking
+    -L [KIND=]PATH      Add a directory to the library search path. The
+                        optional KIND can be one of dependency, crate, native,
+                        framework, or all (the default).
+    -l [KIND[:MODIFIERS]=]NAME[:RENAME]
+                        Link the generated crate(s) to the specified native
+                        library NAME. The optional KIND can be one of
+                        static, framework, or dylib (the default).
+                        Optional comma separated MODIFIERS
+                        (bundle|verbatim|whole-archive|as-needed)
+                        may be specified each with a prefix of either '+' to
+                        enable or '-' to disable.
+        --crate-type [bin|lib|rlib|dylib|cdylib|staticlib|proc-macro]
+                        Comma separated list of types of crates
+                        for the compiler to emit
+        --crate-name NAME
+                        Specify the name of the crate being built
+        --edition 2015|2018|2021|2024
+                        Specify which edition of the compiler to use when
+                        compiling code. The default is 2015 and the latest
+                        stable edition is 2021.
+        --emit [asm|llvm-bc|llvm-ir|obj|metadata|link|dep-info|mir]
+                        Comma separated list of types of output for the
+                        compiler to emit
+        --print [crate-name|file-names|sysroot|target-libdir|cfg|check-cfg|calling-conventions|target-list|target-cpus|target-features|relocation-models|code-models|tls-models|target-spec-json|all-target-specs-json|native-static-libs|stack-protector-strategies|link-args|deployment-target]
+                        Compiler information to print on stdout
+    -g                  Equivalent to -C debuginfo=2
+    -O                  Equivalent to -C opt-level=2
+    -o FILENAME         Write output to <filename>
+        --out-dir DIR   Write output to compiler-chosen filename in <dir>
+        --explain OPT   Provide a detailed explanation of an error message
+        --test          Build a test harness
+        --target TARGET Target triple for which the code is compiled
+    -A, --allow LINT    Set lint allowed
+    -W, --warn LINT     Set lint warnings
+        --force-warn LINT
+                        Set lint force-warn
+    -D, --deny LINT     Set lint denied
+    -F, --forbid LINT   Set lint forbidden
+        --cap-lints LEVEL
+                        Set the most restrictive lint level. More restrictive
+                        lints are capped at this level
+    -C, --codegen OPT[=VALUE]
+                        Set a codegen option
+    -V, --version       Print version info and exit
+    -v, --verbose       Use verbose output
+        --extern NAME[=PATH]
+                        Specify where an external rust library is located
+        --sysroot PATH  Override the system root
+        --error-format human|json|short
+                        How errors and other messages are produced
+        --json CONFIG   Configure the JSON output of the compiler
+        --color auto|always|never
+                        Configure coloring of output:
+                        auto = colorize, if output goes to a tty (default);
+                        always = always colorize output;
+                        never = never colorize output
+        --diagnostic-width WIDTH
+                        Inform rustc of the width of the output so that
+                        diagnostics can be truncated to fit
+        --remap-path-prefix FROM=TO
+                        Remap source names in all output (compiler messages
+                        and output files)
+    @path               Read newline separated options from `path`
+
+Additional help:
+    -C help             Print codegen options
+    -W help             Print 'lint' options and default settings
+    -Z help             Print unstable compiler options
+
diff --git a/tests/run-make/rustc-help/help.stdout b/tests/run-make/rustc-help/help.stdout
new file mode 100644
index 00000000000..a7d07162799
--- /dev/null
+++ b/tests/run-make/rustc-help/help.stdout
@@ -0,0 +1,60 @@
+Usage: rustc [OPTIONS] INPUT
+
+Options:
+    -h, --help          Display this message
+        --cfg SPEC      Configure the compilation environment.
+                        SPEC supports the syntax `NAME[="VALUE"]`.
+        --check-cfg SPEC
+                        Provide list of expected cfgs for checking
+    -L [KIND=]PATH      Add a directory to the library search path. The
+                        optional KIND can be one of dependency, crate, native,
+                        framework, or all (the default).
+    -l [KIND[:MODIFIERS]=]NAME[:RENAME]
+                        Link the generated crate(s) to the specified native
+                        library NAME. The optional KIND can be one of
+                        static, framework, or dylib (the default).
+                        Optional comma separated MODIFIERS
+                        (bundle|verbatim|whole-archive|as-needed)
+                        may be specified each with a prefix of either '+' to
+                        enable or '-' to disable.
+        --crate-type [bin|lib|rlib|dylib|cdylib|staticlib|proc-macro]
+                        Comma separated list of types of crates
+                        for the compiler to emit
+        --crate-name NAME
+                        Specify the name of the crate being built
+        --edition 2015|2018|2021|2024
+                        Specify which edition of the compiler to use when
+                        compiling code. The default is 2015 and the latest
+                        stable edition is 2021.
+        --emit [asm|llvm-bc|llvm-ir|obj|metadata|link|dep-info|mir]
+                        Comma separated list of types of output for the
+                        compiler to emit
+        --print [crate-name|file-names|sysroot|target-libdir|cfg|check-cfg|calling-conventions|target-list|target-cpus|target-features|relocation-models|code-models|tls-models|target-spec-json|all-target-specs-json|native-static-libs|stack-protector-strategies|link-args|deployment-target]
+                        Compiler information to print on stdout
+    -g                  Equivalent to -C debuginfo=2
+    -O                  Equivalent to -C opt-level=2
+    -o FILENAME         Write output to <filename>
+        --out-dir DIR   Write output to compiler-chosen filename in <dir>
+        --explain OPT   Provide a detailed explanation of an error message
+        --test          Build a test harness
+        --target TARGET Target triple for which the code is compiled
+    -A, --allow LINT    Set lint allowed
+    -W, --warn LINT     Set lint warnings
+        --force-warn LINT
+                        Set lint force-warn
+    -D, --deny LINT     Set lint denied
+    -F, --forbid LINT   Set lint forbidden
+        --cap-lints LEVEL
+                        Set the most restrictive lint level. More restrictive
+                        lints are capped at this level
+    -C, --codegen OPT[=VALUE]
+                        Set a codegen option
+    -V, --version       Print version info and exit
+    -v, --verbose       Use verbose output
+
+Additional help:
+    -C help             Print codegen options
+    -W help             Print 'lint' options and default settings
+    -Z help             Print unstable compiler options
+    --help -v           Print the full set of options rustc accepts
+
diff --git a/tests/run-make/rustc-help/rmake.rs b/tests/run-make/rustc-help/rmake.rs
new file mode 100644
index 00000000000..85e90e6352d
--- /dev/null
+++ b/tests/run-make/rustc-help/rmake.rs
@@ -0,0 +1,21 @@
+// Tests `rustc --help` and similar invocations against snapshots and each other.
+
+use run_make_support::{bare_rustc, diff, similar};
+
+fn main() {
+    // `rustc --help`
+    let help = bare_rustc().arg("--help").run().stdout_utf8();
+    diff().expected_file("help.stdout").actual_text("(rustc --help)", &help).run();
+
+    // `rustc` should be the same as `rustc --help`
+    let bare = bare_rustc().run().stdout_utf8();
+    diff().expected_text("(rustc --help)", &help).actual_text("(rustc)", &bare).run();
+
+    // `rustc --help -v` should give a similar but longer help message
+    let help_v = bare_rustc().arg("--help").arg("-v").run().stdout_utf8();
+    diff().expected_file("help-v.stdout").actual_text("(rustc --help -v)", &help_v).run();
+
+    // Check the diff between `rustc --help` and `rustc --help -v`.
+    let help_v_diff = similar::TextDiff::from_lines(&help, &help_v).unified_diff().to_string();
+    diff().expected_file("help-v.diff").actual_text("actual", &help_v_diff).run();
+}