Auto merge of #65241 - tmiasko:no-std-san, r=alexcrichton

build-std compatible sanitizer support

### Motivation

When using `-Z sanitizer=*` feature it is essential that both user code and
standard library is instrumented. Otherwise the utility of sanitizer will be
limited, or its use will be impractical like in the case of memory sanitizer.

The recently introduced cargo feature build-std makes it possible to rebuild
standard library with arbitrary rustc flags. Unfortunately, those changes alone
do not make it easy to rebuild standard library with sanitizers, since runtimes
are dependencies of std that have to be build in specific environment,
generally not available outside rustbuild process. Additionally rebuilding them
requires presence of llvm-config and compiler-rt sources.

The goal of changes proposed here is to make it possible to avoid rebuilding
sanitizer runtimes when rebuilding the std, thus making it possible to
instrument standard library for use with sanitizer with simple, although
verbose command:

```
env CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUSTFLAGS=-Zsanitizer=thread cargo test -Zbuild-std --target x86_64-unknown-linux-gnu
```

### Implementation

* Sanitizer runtimes are no long packed into crates. Instead, libraries build
  from compiler-rt are used as is, after renaming them into `librusc_rt.*`.
* rustc obtains runtimes from target libdir for default sysroot, so that
  they are not required in custom build sysroots created with build-std.
* The runtimes are only linked-in into executables to address issue #64629.
  (in previous design it was hard to avoid linking runtimes into static
  libraries produced by rustc as demonstrated by sanitizer-staticlib-link
  test, which still passes despite changes made in #64780).

cc @kennytm, @japaric, @firstyear, @choller

8 files changed, 5 insertions, 38 deletions

diff --git a/src/test/run-make-fulldeps/sanitizer-address/Makefile b/src/test/run-make-fulldeps/sanitizer-address/Makefile
index 3a377c32993..7f5e9049b2f 100644
--- a/src/test/run-make-fulldeps/sanitizer-address/Makefile
+++ b/src/test/run-make-fulldeps/sanitizer-address/Makefile
@@ -23,7 +23,7 @@ endif
 endif
 
 all:
-	$(RUSTC) -g -Z sanitizer=address -Z print-link-args $(EXTRA_RUSTFLAG) overflow.rs | $(CGREP) librustc_asan
+	$(RUSTC) -g -Z sanitizer=address -Z print-link-args $(EXTRA_RUSTFLAG) overflow.rs | $(CGREP) rustc_rt.asan
 	# Verify that stack buffer overflow is detected:
 	$(TMPDIR)/overflow 2>&1 | $(CGREP) stack-buffer-overflow
 	# Verify that variable name is included in address sanitizer report:
diff --git a/src/test/run-make-fulldeps/sanitizer-invalid-cratetype/Makefile b/src/test/run-make-fulldeps/sanitizer-invalid-cratetype/Makefile
deleted file mode 100644
index 9581ac565ea..00000000000
--- a/src/test/run-make-fulldeps/sanitizer-invalid-cratetype/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-# needs-sanitizer-support
-
--include ../tools.mk
-
-# NOTE the address sanitizer only supports x86_64 linux and macOS
-
-ifeq ($(TARGET),x86_64-apple-darwin)
-EXTRA_RUSTFLAG=-C rpath
-else
-ifeq ($(TARGET),x86_64-unknown-linux-gnu)
-EXTRA_RUSTFLAG=
-endif
-endif
-
-all:
-	$(RUSTC) -Z sanitizer=address --crate-type proc-macro --target $(TARGET) hello.rs 2>&1 | $(CGREP) '-Z sanitizer'
diff --git a/src/test/run-make-fulldeps/sanitizer-invalid-cratetype/hello.rs b/src/test/run-make-fulldeps/sanitizer-invalid-cratetype/hello.rs
deleted file mode 100644
index e7a11a969c0..00000000000
--- a/src/test/run-make-fulldeps/sanitizer-invalid-cratetype/hello.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn main() {
-    println!("Hello, world!");
-}
diff --git a/src/test/run-make-fulldeps/sanitizer-invalid-target/Makefile b/src/test/run-make-fulldeps/sanitizer-invalid-target/Makefile
index df8afee15ce..2a23f0fe3d4 100644
--- a/src/test/run-make-fulldeps/sanitizer-invalid-target/Makefile
+++ b/src/test/run-make-fulldeps/sanitizer-invalid-target/Makefile
@@ -2,4 +2,4 @@
 
 all:
 	$(RUSTC) -Z sanitizer=leak --target i686-unknown-linux-gnu hello.rs 2>&1 | \
-		$(CGREP) 'LeakSanitizer only works with the `x86_64-unknown-linux-gnu` target'
+		$(CGREP) 'LeakSanitizer only works with the `x86_64-unknown-linux-gnu` or `x86_64-apple-darwin` target'
diff --git a/src/test/run-make-fulldeps/sanitizer-leak/Makefile b/src/test/run-make-fulldeps/sanitizer-leak/Makefile
index 101e8272ab9..d8598b8ac93 100644
--- a/src/test/run-make-fulldeps/sanitizer-leak/Makefile
+++ b/src/test/run-make-fulldeps/sanitizer-leak/Makefile
@@ -7,5 +7,5 @@
 # FIXME(#46126) ThinLTO for libstd broke this test
 
 all:
-	$(RUSTC) -C opt-level=1 -g -Z sanitizer=leak -Z print-link-args leak.rs | $(CGREP) librustc_lsan
+	$(RUSTC) -C opt-level=1 -g -Z sanitizer=leak -Z print-link-args leak.rs | $(CGREP) rustc_rt.lsan
 	$(TMPDIR)/leak 2>&1 | $(CGREP) 'detected memory leaks'
diff --git a/src/test/run-make-fulldeps/sanitizer-memory/Makefile b/src/test/run-make-fulldeps/sanitizer-memory/Makefile
index f5787903a2b..8bc9df1b4ba 100644
--- a/src/test/run-make-fulldeps/sanitizer-memory/Makefile
+++ b/src/test/run-make-fulldeps/sanitizer-memory/Makefile
@@ -5,7 +5,7 @@
 # only-x86_64
 
 all:
-	$(RUSTC) -g -Z sanitizer=memory -Z print-link-args uninit.rs | $(CGREP) librustc_msan
+	$(RUSTC) -g -Z sanitizer=memory -Z print-link-args uninit.rs | $(CGREP) rustc_rt.msan
 	$(TMPDIR)/uninit 2>&1 | $(CGREP) use-of-uninitialized-value
-	$(RUSTC) -g -Z sanitizer=memory -Z print-link-args maybeuninit.rs | $(CGREP) librustc_msan
+	$(RUSTC) -g -Z sanitizer=memory -Z print-link-args maybeuninit.rs | $(CGREP) rustc_rt.msan
 	$(TMPDIR)/maybeuninit 2>&1 | $(CGREP) use-of-uninitialized-value
diff --git a/src/test/ui/feature-gates/feature-gate-sanitizer-runtime.rs b/src/test/ui/feature-gates/feature-gate-sanitizer-runtime.rs
deleted file mode 100644
index 3b972c117a6..00000000000
--- a/src/test/ui/feature-gates/feature-gate-sanitizer-runtime.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-#![sanitizer_runtime] //~ ERROR the `#[sanitizer_runtime]` attribute is
-
-fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-sanitizer-runtime.stderr b/src/test/ui/feature-gates/feature-gate-sanitizer-runtime.stderr
deleted file mode 100644
index b13ec215f8c..00000000000
--- a/src/test/ui/feature-gates/feature-gate-sanitizer-runtime.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error[E0658]: the `#[sanitizer_runtime]` attribute is used to identify crates that contain the runtime of a sanitizer and will never be stable
-  --> $DIR/feature-gate-sanitizer-runtime.rs:1:1
-   |
-LL | #![sanitizer_runtime]
-   | ^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: add `#![feature(sanitizer_runtime)]` to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.