From 445d95023b1d9d152417838c4edad54f7bf4efe3 Mon Sep 17 00:00:00 2001
From: Ophestra <cat@gensokyo.uk>
Date: Fri, 1 May 2026 03:42:14 +0900
Subject: [PATCH] internal/rosa: global preset flags

These changes preset behaviour globally. Useful for ad hoc workarounds for development or bootstrapping on resource-constrained systems.

Signed-off-by: Ophestra <cat@gensokyo.uk>
---
 cmd/mbf/main.go            | 19 +++++++++++++++++++
 internal/rosa/all.go       | 16 +++++++++++++++-
 internal/rosa/all_test.go  |  5 ++++-
 internal/rosa/cmake.go     |  2 +-
 internal/rosa/llvm.go      | 10 +++++++---
 internal/rosa/make.go      |  2 +-
 internal/rosa/meson.go     |  2 +-
 internal/rosa/rosa_test.go |  5 ++++-
 8 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/cmd/mbf/main.go b/cmd/mbf/main.go
index 1a986ca7..68d418b5 100644
--- a/cmd/mbf/main.go
+++ b/cmd/mbf/main.go
@@ -63,6 +63,8 @@ func main() {
 
 	var (
 		flagQuiet bool
+		flagCheck bool
+		flagLTO   bool
 
 		addr net.UnixAddr
 	)
@@ -80,11 +82,28 @@ func main() {
 			addr.Name = filepath.Join(cm.base, "daemon")
 		}
 
+		var flags int
+		if !flagCheck {
+			flags |= rosa.OptSkipCheck
+		}
+		if !flagLTO {
+			flags |= rosa.OptLLVMNoLTO
+		}
+		rosa.DropCaches(flags)
+
 		return nil
 	}).Flag(
 		&flagQuiet,
 		"q", command.BoolFlag(false),
 		"Do not print cure messages",
+	).Flag(
+		&flagLTO,
+		"lto", command.BoolFlag(false),
+		"Enable LTO in stage2 and stage3 LLVM toolchains",
+	).Flag(
+		&flagCheck,
+		"check", command.BoolFlag(true),
+		"Run test suites",
 	).Flag(
 		&cm.cures,
 		"cures", command.IntFlag(0),
diff --git a/internal/rosa/all.go b/internal/rosa/all.go
index f61ec62f..fb745c0a 100644
--- a/internal/rosa/all.go
+++ b/internal/rosa/all.go
@@ -322,15 +322,29 @@ var (
 	}
 	// artifactsOnce is for lazy initialisation of artifacts.
 	artifactsOnce [_toolchainEnd][len(artifactsM)]sync.Once
+
+	// presetOpts globally modifies behaviour of presets.
+	presetOpts int
 )
 
+const (
+	// OptSkipCheck skips running all test suites.
+	OptSkipCheck = 1 << iota
+	// OptLLVMNoLTO disables LTO in all [LLVM] stages.
+	OptLLVMNoLTO
+)
+
+// Flags returns the current preset flags
+func Flags() int { return presetOpts }
+
 // zero zeros the value pointed to by p.
 func zero[T any](p *T) { var v T; *p = v }
 
 // DropCaches arranges for all cached [pkg.Artifact] to be freed some time after
 // it returns. Must not be used concurrently with any other function from this
 // package.
-func DropCaches() {
+func DropCaches(flags int) {
+	presetOpts = flags
 	zero(&artifacts)
 	zero(&artifactsOnce)
 }
diff --git a/internal/rosa/all_test.go b/internal/rosa/all_test.go
index f97ebbdf..52eabf39 100644
--- a/internal/rosa/all_test.go
+++ b/internal/rosa/all_test.go
@@ -20,13 +20,16 @@ func TestLoad(t *testing.T) {
 }
 
 func BenchmarkAll(b *testing.B) {
+	flags := rosa.Flags()
+	b.Cleanup(func() { rosa.DropCaches(flags) })
+
 	for b.Loop() {
 		for i := range rosa.PresetEnd {
 			rosa.Std.Load(rosa.PArtifact(i))
 		}
 
 		b.StopTimer()
-		rosa.DropCaches()
+		rosa.DropCaches(0)
 		b.StartTimer()
 	}
 }
diff --git a/internal/rosa/cmake.go b/internal/rosa/cmake.go
index 802a0b30..bfa035c0 100644
--- a/internal/rosa/cmake.go
+++ b/internal/rosa/cmake.go
@@ -185,7 +185,7 @@ func (attr *CMakeHelper) script(name string) string {
 	}
 
 	script := attr.Script
-	if !attr.SkipTest {
+	if !attr.SkipTest && presetOpts&OptSkipCheck == 0 {
 		script += "\n" + test
 	}
 
diff --git a/internal/rosa/llvm.go b/internal/rosa/llvm.go
index a7930e1b..6177a716 100644
--- a/internal/rosa/llvm.go
+++ b/internal/rosa/llvm.go
@@ -90,10 +90,14 @@ func (t Toolchain) newLLVM() (pkg.Artifact, string) {
 			skipChecks[i] = s
 		}
 
-		cache = append(cache, []KV{
-			// very expensive
-			{"LLVM_ENABLE_LTO", "Thin"},
+		if presetOpts&OptLLVMNoLTO == 0 {
+			cache = append(cache, []KV{
+				// very expensive
+				{"LLVM_ENABLE_LTO", "Thin"},
+			}...)
+		}
 
+		cache = append(cache, []KV{
 			// symbols: clock_gettime, mallopt
 			{"COMPILER_RT_INCLUDE_TESTS", "OFF"},
 
diff --git a/internal/rosa/make.go b/internal/rosa/make.go
index ecec3a5d..c283e5fb 100644
--- a/internal/rosa/make.go
+++ b/internal/rosa/make.go
@@ -194,7 +194,7 @@ make \
 	}
 	scriptMake += "\n"
 
-	if !attr.SkipCheck {
+	if !attr.SkipCheck && presetOpts&OptSkipCheck == 0 {
 		scriptMake += attr.ScriptCheckEarly + `make \
 	` + jobsFlagE + ` \
 	`
diff --git a/internal/rosa/meson.go b/internal/rosa/meson.go
index 4b778a75..638074b9 100644
--- a/internal/rosa/meson.go
+++ b/internal/rosa/meson.go
@@ -117,7 +117,7 @@ func (attr *MesonHelper) script(name string) string {
 	}
 
 	var scriptTest string
-	if !attr.SkipTest {
+	if !attr.SkipTest && presetOpts&OptSkipCheck == 0 {
 		scriptTest = `
 meson test \
 	--print-errorlogs`
diff --git a/internal/rosa/rosa_test.go b/internal/rosa/rosa_test.go
index b64ebbd7..ceb7e79c 100644
--- a/internal/rosa/rosa_test.go
+++ b/internal/rosa/rosa_test.go
@@ -93,11 +93,14 @@ func TestCureAll(t *testing.T) {
 }
 
 func BenchmarkStage3(b *testing.B) {
+	flags := rosa.Flags()
+	b.Cleanup(func() { rosa.DropCaches(flags) })
+
 	for b.Loop() {
 		rosa.Std.Load(rosa.LLVM)
 
 		b.StopTimer()
-		rosa.DropCaches()
+		rosa.DropCaches(0)
 		b.StartTimer()
 	}
 }