merge `if-available` and `if-unchanged` for `download-ci-llvm`

Signed-off-by: onur-ozkan <work@onurozkan.dev>

config.example.toml

@@ -42,18 +42,15 @@ change-id = 116881
 # Unless you're developing for a target where Rust CI doesn't build a compiler
 # toolchain or changing LLVM locally, you probably want to leave this enabled.
 #
-# Set this to `"if-available"` if you are not sure whether you're on a tier 1 
-# target. All tier 1 targets are currently supported;
-#
-# We also currently only support this when building LLVM for the build triple.
-#
-# Set this to `"if-unchanged"` to only download if the llvm-project have not 
-# been modified. (If there are no changes or if built from tarball source, 
-# the logic is the same as "if-available")
+# Set this to `"if-unchanged"` to download only if the llvm-project has not
+# been modified. You can also use this if you are unsure whether you're on a
+# tier 1 target. All tier 1 targets are currently supported.
+
+# Currently, we only support this when building LLVM for the build triple.
 #
 # Note that many of the LLVM options are not currently supported for
 # downloading. Currently only the "assertions" option can be toggled.
-#download-ci-llvm = if rust.channel == "dev" { "if-available" } else { false }
+#download-ci-llvm = if rust.channel == "dev" { "if-unchanged" } else { false }
 
 # Indicates whether the LLVM build is a Release or Debug build
 #optimize = true

src/bootstrap/defaults/config.compiler.toml

@@ -17,4 +17,4 @@ lto = "off"
 
 [llvm]
 # Will download LLVM from CI if available on your platform.
-download-ci-llvm = "if-available"
+download-ci-llvm = "if-unchanged"

src/bootstrap/defaults/config.library.toml

@@ -13,4 +13,4 @@ lto = "off"
 
 [llvm]
 # Will download LLVM from CI if available on your platform.
-download-ci-llvm = "if-available"
+download-ci-llvm = "if-unchanged"

src/bootstrap/defaults/config.tools.toml

@@ -21,4 +21,4 @@ compiler-docs = true
 
 [llvm]
 # Will download LLVM from CI if available on your platform.
-download-ci-llvm = "if-available"
+download-ci-llvm = "if-unchanged"

src/bootstrap/src/core/config/config.rs

@@ -2104,6 +2104,8 @@ impl Config {
         match download_ci_llvm {
             None => self.channel == "dev" && llvm::is_ci_llvm_available(&self, asserts),
             Some(StringOrBool::Bool(b)) => b,
+            // FIXME: "if-available" is deprecated. Remove this block later (around mid 2024)
+            // to not break builds between the recent-to-old checkouts.
             Some(StringOrBool::String(s)) if s == "if-available" => {
                 llvm::is_ci_llvm_available(&self, asserts)
             }

src/bootstrap/src/tests/config.rs

@@ -24,19 +24,19 @@ fn download_ci_llvm() {
     }
 
     let parse_llvm = |s| parse(s).llvm_from_ci;
-    let if_available = parse_llvm("llvm.download-ci-llvm = \"if-available\"");
+    let if_unchanged = parse_llvm("llvm.download-ci-llvm = \"if-unchanged\"");
 
     assert!(parse_llvm("llvm.download-ci-llvm = true"));
     assert!(!parse_llvm("llvm.download-ci-llvm = false"));
-    assert_eq!(parse_llvm(""), if_available);
-    assert_eq!(parse_llvm("rust.channel = \"dev\""), if_available);
+    assert_eq!(parse_llvm(""), if_unchanged);
+    assert_eq!(parse_llvm("rust.channel = \"dev\""), if_unchanged);
     assert!(!parse_llvm("rust.channel = \"stable\""));
     assert!(parse_llvm("build.build = \"x86_64-unknown-linux-gnu\""));
     assert!(parse_llvm(
-        "llvm.assertions = true \r\n build.build = \"x86_64-unknown-linux-gnu\" \r\n llvm.download-ci-llvm = \"if-available\""
+        "llvm.assertions = true \r\n build.build = \"x86_64-unknown-linux-gnu\" \r\n llvm.download-ci-llvm = \"if-unchanged\""
     ));
     assert!(!parse_llvm(
-        "llvm.assertions = true \r\n build.build = \"aarch64-apple-darwin\" \r\n llvm.download-ci-llvm = \"if-available\""
+        "llvm.assertions = true \r\n build.build = \"aarch64-apple-darwin\" \r\n llvm.download-ci-llvm = \"if-unchanged\""
     ));
 }
 

src/ci/run.sh

@@ -145,7 +145,7 @@ else
   # LLVM continuously on at least some builders to ensure it works, though.
   # (And PGO is its own can of worms).
   if [ "$NO_DOWNLOAD_CI_LLVM" = "" ]; then
-    RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.download-ci-llvm=if-available"
+    RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.download-ci-llvm=if-unchanged"
   else
     # When building for CI we want to use the static C++ Standard library
     # included with LLVM, since a dynamic libstdcpp may not be available.

src/ci/scripts/install-clang.sh

@@ -58,7 +58,7 @@ elif isWindows && [[ ${CUSTOM_MINGW-0} -ne 1 ]]; then
         "${RUST_CONFIGURE_ARGS} --set llvm.clang-cl=$(pwd)/clang-rust/bin/clang-cl.exe"
 
     # Disable downloading CI LLVM on this builder;
-    # setting up clang-cl just above conflicts with the default if-available option.
+    # setting up clang-cl just above conflicts with the default if-unchanged option.
     ciCommandSetEnv NO_DOWNLOAD_CI_LLVM 1
 fi