rust: Propagate MTO libs linked whole through dylibs.

Because dylibs don't export symbols of whole-archive staticlibs, we
simulate this by propagating those static libs through to dependent
modules. Similarly, we must do the same for rlibs from cc_* modules used
to generate MTO staticlibs.

Bug: 395915782
Test: New soong tests
Test: m rust
Change-Id: I83d6a08234af04af5039764f5a80f659b24aa132

3 files changed, 94 insertions, 9 deletions

diff --git a/rust/library.go b/rust/library.go
index 7f5861fe8..415785a16 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -744,10 +744,16 @@ func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps Pa
 		}
 		if library.rlib() {
 			ccExporter.RustRlibDeps = append(ccExporter.RustRlibDeps, deps.reexportedCcRlibDeps...)
+			ccExporter.RustRlibDeps = append(ccExporter.RustRlibDeps, deps.reexportedWholeCcRlibDeps...)
 		}
 		android.SetProvider(ctx, cc.FlagExporterInfoProvider, ccExporter)
 	}
 
+	if library.dylib() {
+		// reexport whole-static'd dependencies for dylibs.
+		library.flagExporter.wholeRustRlibDeps = append(library.flagExporter.wholeRustRlibDeps, deps.reexportedWholeCcRlibDeps...)
+	}
+
 	if library.shared() || library.stubs() {
 		// Optimize out relinking against shared libraries whose interface hasn't changed by
 		// depending on a table of contents file instead of the library itself.
diff --git a/rust/rust.go b/rust/rust.go
index 7a7b1064c..a02ca6073 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -496,8 +496,9 @@ type PathDeps struct {
 	depLinkFlags []string
 
 	// track cc static-libs that have Rlib dependencies
-	reexportedCcRlibDeps []cc.RustRlibDep
-	ccRlibDeps           []cc.RustRlibDep
+	reexportedCcRlibDeps      []cc.RustRlibDep
+	reexportedWholeCcRlibDeps []cc.RustRlibDep
+	ccRlibDeps                []cc.RustRlibDep
 
 	// linkDirs are link paths passed via -L to rustc. linkObjects are objects passed directly to the linker
 	// Both of these are exported and propagate to dependencies.
@@ -555,6 +556,7 @@ type flagExporter struct {
 	staticLibObjects      []string
 	sharedLibObjects      []string
 	wholeStaticLibObjects []string
+	wholeRustRlibDeps     []cc.RustRlibDep
 }
 
 func (flagExporter *flagExporter) exportLinkDirs(dirs ...string) {
@@ -584,6 +586,7 @@ func (flagExporter *flagExporter) setRustProvider(ctx ModuleContext) {
 		StaticLibObjects:      flagExporter.staticLibObjects,
 		WholeStaticLibObjects: flagExporter.wholeStaticLibObjects,
 		SharedLibPaths:        flagExporter.sharedLibObjects,
+		WholeRustRlibDeps:     flagExporter.wholeRustRlibDeps,
 	})
 }
 
@@ -600,6 +603,7 @@ type RustFlagExporterInfo struct {
 	StaticLibObjects      []string
 	WholeStaticLibObjects []string
 	SharedLibPaths        []string
+	WholeRustRlibDeps     []cc.RustRlibDep
 }
 
 var RustFlagExporterInfoProvider = blueprint.NewProvider[RustFlagExporterInfo]()
@@ -1585,8 +1589,8 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 				directSrcProvidersDeps = append(directSrcProvidersDeps, &dep)
 			}
 
+			exportedRustInfo, _ := android.OtherModuleProvider(ctx, dep, RustFlagExporterInfoProvider)
 			exportedInfo, _ := android.OtherModuleProvider(ctx, dep, RustFlagExporterInfoProvider)
-
 			//Append the dependencies exported objects, except for proc-macros which target a different arch/OS
 			if depTag != procMacroDepTag {
 				depPaths.depFlags = append(depPaths.depFlags, exportedInfo.Flags...)
@@ -1595,6 +1599,11 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 				depPaths.staticLibObjects = append(depPaths.staticLibObjects, exportedInfo.StaticLibObjects...)
 				depPaths.wholeStaticLibObjects = append(depPaths.wholeStaticLibObjects, exportedInfo.WholeStaticLibObjects...)
 				depPaths.linkDirs = append(depPaths.linkDirs, exportedInfo.LinkDirs...)
+
+				depPaths.reexportedWholeCcRlibDeps = append(depPaths.reexportedWholeCcRlibDeps, exportedRustInfo.WholeRustRlibDeps...)
+				if !mod.Rlib() {
+					depPaths.ccRlibDeps = append(depPaths.ccRlibDeps, exportedRustInfo.WholeRustRlibDeps...)
+				}
 			}
 
 			if depTag == dylibDepTag || depTag == rlibDepTag || depTag == procMacroDepTag {
@@ -1656,17 +1665,26 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 					}
 				}
 
+				exportedInfo, _ := android.OtherModuleProvider(ctx, dep, cc.FlagExporterInfoProvider)
 				if cc.IsWholeStaticLib(depTag) {
 					// Add whole staticlibs to wholeStaticLibObjects to propagate to Rust all dependents.
 					depPaths.wholeStaticLibObjects = append(depPaths.wholeStaticLibObjects, ccLibPath.String())
+
+					// We also propagate forward whole-static'd cc staticlibs with rust_ffi_rlib dependencies
+					// We don't need to check a hypothetical exportedRustInfo.WholeRustRlibDeps because we
+					// wouldn't expect a rust_ffi_rlib to be listed in `static_libs` (Soong explicitly disallows this)
+					depPaths.reexportedWholeCcRlibDeps = append(depPaths.reexportedWholeCcRlibDeps, exportedInfo.RustRlibDeps...)
 				} else {
-					// Otherwise add to staticLibObjects, which only propagate through rlibs to their dependents.
+					// If not whole_static, add to staticLibObjects, which only propagate through rlibs to their dependents.
 					depPaths.staticLibObjects = append(depPaths.staticLibObjects, ccLibPath.String())
+
+					if mod.Rlib() {
+						// rlibs propagate their inherited rust_ffi_rlibs forward.
+						depPaths.reexportedCcRlibDeps = append(depPaths.reexportedCcRlibDeps, exportedInfo.RustRlibDeps...)
+					}
 				}
 
 				depPaths.linkDirs = append(depPaths.linkDirs, linkPath)
-
-				exportedInfo, _ := android.OtherModuleProvider(ctx, dep, cc.FlagExporterInfoProvider)
 				depPaths.depIncludePaths = append(depPaths.depIncludePaths, exportedInfo.IncludeDirs...)
 				depPaths.depSystemIncludePaths = append(depPaths.depSystemIncludePaths, exportedInfo.SystemIncludeDirs...)
 				depPaths.depClangFlags = append(depPaths.depClangFlags, exportedInfo.Flags...)
@@ -1675,8 +1693,6 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 				if !mod.Rlib() {
 					// rlibs don't need to build the generated static library, so they don't need to track these.
 					depPaths.ccRlibDeps = append(depPaths.ccRlibDeps, exportedInfo.RustRlibDeps...)
-				} else {
-					depPaths.reexportedCcRlibDeps = append(depPaths.reexportedCcRlibDeps, exportedInfo.RustRlibDeps...)
 				}
 
 				directStaticLibDeps = append(directStaticLibDeps, linkableInfo)
@@ -1835,6 +1851,7 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 	depPaths.depSystemIncludePaths = android.FirstUniquePaths(depPaths.depSystemIncludePaths)
 	depPaths.depLinkFlags = android.FirstUniqueStrings(depPaths.depLinkFlags)
 	depPaths.reexportedCcRlibDeps = android.FirstUniqueFunc(depPaths.reexportedCcRlibDeps, cc.EqRustRlibDeps)
+	depPaths.reexportedWholeCcRlibDeps = android.FirstUniqueFunc(depPaths.reexportedWholeCcRlibDeps, cc.EqRustRlibDeps)
 	depPaths.ccRlibDeps = android.FirstUniqueFunc(depPaths.ccRlibDeps, cc.EqRustRlibDeps)
 
 	return depPaths
diff --git a/rust/rust_test.go b/rust/rust_test.go
index fbb994752..f634bb5cd 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -456,6 +456,13 @@ func TestRustFFIRlibs(t *testing.T) {
 		}
 
 		rust_ffi_static {
+			name: "libfoo_from_rlib_whole",
+			crate_name: "foo_from_rlib_whole",
+			srcs: ["src/lib.rs"],
+			export_include_dirs: ["foo_includes"]
+		}
+
+		rust_ffi_static {
 			name: "libbuzz",
 			crate_name: "buzz",
 			srcs: ["src/lib.rs"],
@@ -469,6 +476,13 @@ func TestRustFFIRlibs(t *testing.T) {
 			export_include_dirs: ["buzz_includes"]
 		}
 
+		rust_ffi_static {
+			name: "libbuzz_from_rlib_whole",
+			crate_name: "buzz_from_rlib_whole",
+			srcs: ["src/lib.rs"],
+			export_include_dirs: ["buzz_includes"]
+		}
+
 		cc_library_shared {
 			name: "libcc_shared",
 			srcs:["foo.c"],
@@ -489,6 +503,13 @@ func TestRustFFIRlibs(t *testing.T) {
 			whole_static_libs: ["libfoo_from_rlib"],
 		}
 
+		cc_library_static {
+			name: "libcc_whole_static_from_rlib",
+			srcs:["foo.c"],
+			static_libs: ["libbuzz_from_rlib_whole"],
+			whole_static_libs: ["libfoo_from_rlib_whole"],
+		}
+
 		cc_binary {
 			name: "ccBin",
 			srcs:["foo.c"],
@@ -500,6 +521,14 @@ func TestRustFFIRlibs(t *testing.T) {
 			srcs:["src/foo.rs"],
 			crate_name: "rs",
 			static_libs: ["libcc_static_from_rlib"],
+			whole_static_libs: ["libcc_whole_static_from_rlib"],
+		}
+
+		rust_library {
+			name: "librs2",
+			srcs:["src/foo.rs"],
+			crate_name: "rs",
+			rustlibs: ["librs"],
 		}
 
 		rust_binary {
@@ -509,7 +538,7 @@ func TestRustFFIRlibs(t *testing.T) {
 			rlibs: ["librs", "libbar"],
 			static_libs: ["libcc_static"],
 		}
-		`)
+	`)
 
 	libbar := ctx.ModuleForTests(t, "libbar", "android_arm64_armv8-a_rlib_rlib-std").Rule("rustc")
 	libcc_shared_rustc := ctx.ModuleForTests(t, "libcc_shared", "android_arm64_armv8-a_shared").Rule("rustc")
@@ -521,6 +550,10 @@ func TestRustFFIRlibs(t *testing.T) {
 	rustbin_genlib := ctx.ModuleForTests(t, "rsBin", "android_arm64_armv8-a").Output("generated_rust_staticlib/librustlibs.a")
 	rustbin := ctx.ModuleForTests(t, "rsBin", "android_arm64_armv8-a").Output("unstripped/rsBin")
 	librs_rlib := ctx.ModuleForTests(t, "librs", "android_arm64_armv8-a_rlib_dylib-std").MaybeOutput("generated_rust_staticlib/librustlibs.a")
+	librs2_rlib := ctx.ModuleForTests(t, "librs2", "android_arm64_armv8-a_rlib_dylib-std").MaybeOutput("generated_rust_staticlib/librustlibs.a")
+	librs_genlib := ctx.ModuleForTests(t, "librs", "android_arm64_armv8-a_dylib").Output("generated_rust_staticlib/librustlibs.a")
+	librs2_genlib := ctx.ModuleForTests(t, "librs2", "android_arm64_armv8-a_dylib").Output("generated_rust_staticlib/librustlibs.a")
+	librs2_dylib := ctx.ModuleForTests(t, "librs2", "android_arm64_armv8-a_dylib").Output("unstripped/librs2.dylib.so")
 
 	if !strings.Contains(libbar.Args["rustcFlags"], "crate-type=rlib") {
 		t.Errorf("missing crate-type for static variant, expecting %#v, rustcFlags: %#v", "rlib", libbar.Args["rustcFlags"])
@@ -578,6 +611,10 @@ func TestRustFFIRlibs(t *testing.T) {
 		t.Errorf("missing generated static library in linker step libFlags in Rust module, expecting %#v, libFlags: %#v",
 			"generated_rust_staticlib/librustlibs.a", rustbin.Args["libFlags"])
 	}
+	if !strings.Contains(librs2_dylib.Args["linkFlags"], "generated_rust_staticlib/librustlibs.a") {
+		t.Errorf("missing generated static library in linker step libFlags in Rust module, expecting %#v, libFlags: %#v",
+			"generated_rust_staticlib/librustlibs.a", librs2_dylib.Args["libFlags"])
+	}
 
 	// Make sure that direct dependencies and indirect whole static dependencies are
 	// propagating correctly for the rlib -> cc_library_static -> rust_* generated library example.
@@ -610,6 +647,31 @@ func TestRustFFIRlibs(t *testing.T) {
 	if librs_rlib.Rule != nil {
 		t.Error("rlibs should not be generating mto staticlibs", "rlib", libbar.Args["rustcFlags"])
 	}
+	if librs2_rlib.Rule != nil {
+		t.Error("rlibs should not be generating mto staticlibs", "rlib", libbar.Args["rustcFlags"])
+	}
+
+	// Make sure that direct whole static dependencies are propagating correctly downstream
+	// foo_from_rlib_whole --(ws)--> libcc_whole_static_from_rlib --(ws)--> librs
+	if !strings.Contains(librs_genlib.Args["libFlags"], "--extern foo_from_rlib_whole=") {
+		t.Errorf("Missing direct whole_static_lib dependency libfoo_from_rlib_whole from rust dylib when writing generated Rust staticlib: %#v", librs_genlib.Args["libFlags"])
+	}
+
+	// Make sure that indirect whole static dependencies are propagating correctly downstream
+	// foo_from_rlib_whole --(ws)--> libcc_whole_static_from_rlib --(ws)--> librs --> rust_*
+	if !strings.Contains(librs2_genlib.Args["libFlags"], "--extern foo_from_rlib_whole=") {
+		t.Errorf("Missing indirect whole_static_lib dependency libfoo_from_rlib_whole from rust dylib when writing generated Rust staticlib: %#v", librs2_genlib.Args["libFlags"])
+	}
+	if !strings.Contains(rustbin_genlib.Args["libFlags"], "--extern foo_from_rlib_whole=") {
+		t.Errorf("Missing indirect whole_static_lib dependency libfoo_from_rlib_whole from rust dylib in rust binary when writing generated Rust staticlib: %#v", rustbin_genlib.Args["libFlags"])
+	}
+
+	// Make sure that normal static dependencies are not propagating through dylib dependencies
+	// buzz_from_rlib_whole --(s)--> libcc_whole_static_from_rlib --(ws)--> librs --> rust_*
+	if strings.Contains(librs2_genlib.Args["libFlags"], "--extern buzz_from_rlib_whole=") {
+		t.Errorf("dependency from indirect cc staticlib from direct dylib dep found in rust dylib when writing generated Rust staticlib: %#v", librs2_genlib.Args["libFlags"])
+	}
+
 }
 
 func assertString(t *testing.T, got, expected string) {