Auto merge of #128787 - Oneirical:infohazardous-deprogram, r=jieyouxu

Coalesce `dep-info`, `dep-info-spaces` and `dep-info-doesnt-run-much` `run-make` tests into `dep-info` rmake.rs

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

This is one of the most ancient tests in the `run-make` directory and its Makefile does some unexpected things, like creating and deleting a `done` directory over and over, sleeping at certain times (this is the [commit](0d9fd8e2a1) that added the `sleep`).

I tried to preserve the intent of the test, which is smoke-testing that `dep-info` works.

try-job: x86_64-msvc
try-job: i686-mingw
try-job: aarch64-gnu
try-job: aarch64-apple
try-job: test-various
try-job: armhf-gnu
try-job: dist-various-1

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -1,8 +1,5 @@
 run-make/branch-protection-check-IBT/Makefile
 run-make/cat-and-grep-sanity-check/Makefile
-run-make/dep-info-doesnt-run-much/Makefile
-run-make/dep-info-spaces/Makefile
-run-make/dep-info/Makefile
 run-make/emit-to-stdout/Makefile
 run-make/extern-fn-reachable/Makefile
 run-make/incr-add-rust-src-component/Makefile

tests/run-make/dep-info-doesnt-run-much/Makefile

@@ -1,4 +0,0 @@
-include ../tools.mk
-
-all:
-	$(RUSTC) foo.rs --emit dep-info

tests/run-make/dep-info-spaces/Makefile

@@ -1,19 +0,0 @@
-include ../tools.mk
-
-# ignore-windows
-# ignore-freebsd
-# FIXME: (windows: see `../dep-info/Makefile`)
-
-all:
-	cp lib.rs $(TMPDIR)/
-	cp 'foo foo.rs' $(TMPDIR)/
-	cp bar.rs $(TMPDIR)/
-	$(RUSTC) --emit link,dep-info --crate-type=lib $(TMPDIR)/lib.rs
-	sleep 1
-	touch $(TMPDIR)/'foo foo.rs'
-	-rm -f $(TMPDIR)/done
-	$(MAKE) -drf Makefile.foo
-	rm $(TMPDIR)/done
-	pwd
-	$(MAKE) -drf Makefile.foo
-	rm $(TMPDIR)/done && exit 1 || exit 0

tests/run-make/dep-info-spaces/Makefile.foo

@@ -1,7 +0,0 @@
-LIB := $(shell $(RUSTC) --print file-names --crate-type=lib $(TMPDIR)/lib.rs)
-
-$(TMPDIR)/$(LIB):
-	$(RUSTC) --emit link,dep-info --crate-type=lib $(TMPDIR)/lib.rs
-	touch $(TMPDIR)/done
-
--include $(TMPDIR)/lib.d

tests/run-make/dep-info-spaces/bar.rs

@@ -1 +0,0 @@
-pub fn bar() {}

tests/run-make/dep-info/Makefile

@@ -1,25 +0,0 @@
-include ../tools.mk
-
-# ignore-windows
-# ignore-freebsd
-# FIXME: on windows `rustc --dep-info` produces Makefile dependency with
-# windows native paths (e.g. `c:\path\to\libfoo.a`)
-# but msys make seems to fail to recognize such paths, so test fails.
-
-all:
-	cp *.rs $(TMPDIR)
-	$(RUSTC) --emit dep-info,link --crate-type=lib $(TMPDIR)/lib.rs
-	sleep 2
-	touch $(TMPDIR)/foo.rs
-	-rm -f $(TMPDIR)/done
-	$(MAKE) -drf Makefile.foo
-	sleep 2
-	rm $(TMPDIR)/done
-	pwd
-	$(MAKE) -drf Makefile.foo
-	rm $(TMPDIR)/done && exit 1 || exit 0
-
-	# When a source file is deleted `make` should still work
-	rm $(TMPDIR)/bar.rs
-	cp $(TMPDIR)/lib2.rs $(TMPDIR)/lib.rs
-	$(MAKE) -drf Makefile.foo

tests/run-make/dep-info/Makefile.foo

@@ -1,7 +0,0 @@
-LIB := $(shell $(RUSTC) --print file-names --crate-type=lib lib.rs)
-
-$(TMPDIR)/$(LIB):
-	$(RUSTC) --emit dep-info,link --crate-type=lib lib.rs
-	touch $(TMPDIR)/done
-
--include $(TMPDIR)/foo.d

tests/run-make/dep-info/rmake.rs

@@ -0,0 +1,37 @@
+// This is a simple smoke test for rustc's `--emit dep-info` feature. It prints out
+// information about dependencies in a Makefile-compatible format, as a `.d` file.
+// Note that this test does not check that the `.d` file is Makefile-compatible.
+
+// This test first checks that emitting dep-info disables static analysis, preventing
+// compilation of `erroneous.rs` from causing a compilation failure.
+// Then, it checks that compilation using the flag is successful in general, even with
+// empty source files or source files that contain a whitespace character.
+
+// Finally, it removes one dependency and checks that compilation is still successful.
+// See https://github.com/rust-lang/rust/pull/10698
+
+use run_make_support::{rfs, rustc};
+
+fn main() {
+    // We're only emitting dep info, so we shouldn't be running static analysis to
+    // figure out that this program is erroneous.
+    rustc().input("erroneous.rs").emit("dep-info").run();
+
+    rustc().input("lib.rs").emit("dep-info,link").crate_type("lib").run();
+    rfs::remove_file("foo.rs");
+    rfs::create_file("foo.rs");
+    // Compilation should succeed even if `foo.rs` is empty.
+    rustc().input("lib.rs").emit("dep-info,link").crate_type("lib").run();
+
+    // Again, with a space in the filename this time around.
+    rustc().input("lib_foofoo.rs").emit("dep-info,link").crate_type("lib").run();
+    rfs::remove_file("foo foo.rs");
+    rfs::create_file("foo foo.rs");
+    // Compilation should succeed even if `foo foo.rs` is empty.
+    rustc().input("lib_foofoo.rs").emit("dep-info,link").crate_type("lib").run();
+
+    // When a source file is deleted, compilation should still succeed if the library
+    // also loses this source file dependency.
+    rfs::remove_file("bar.rs");
+    rustc().input("lib2.rs").emit("dep-info,link").crate_type("lib").run();
+}