feat: add linkopts property

core/androidbp_cclibs.go

@@ -419,7 +419,7 @@ func addCompilableProps(mod bpwriter.Module, m Compilable, ctx blueprint.ModuleC
 	m.FlagsInTransitive(ctx).ForEachIf(
 		func(f flag.Flag) bool {
 			// Includes are not part of cflags on AOSP, and the exporting of them is done by Soong itself,
-			// hence exclude processing of includes here and handle it seperately.
+			// hence exclude processing of includes here and handle it separately.
 			return !f.MatchesType(flag.TypeInclude)
 		},
 		func(f flag.Flag) {
@@ -432,6 +432,8 @@ func addCompilableProps(mod bpwriter.Module, m Compilable, ctx blueprint.ModuleC
 				cxxFlags = append(cxxFlags, f.ToString())
 			case f.MatchesType(flag.TypeLinker):
 				ldflags = append(ldflags, f.ToString())
+			case f.MatchesType(flag.TypeTransitiveLinker):
+				ldflags = append(ldflags, f.ToString())
 			case f.MatchesType(flag.TypeAsm):
 				asflags = append(asflags, f.ToString())
 			}
@@ -452,7 +454,7 @@ func addCompilableProps(mod bpwriter.Module, m Compilable, ctx blueprint.ModuleC
 		},
 	)
 
-	// Check if any inclues are being exported
+	// Check if any includes are being exported
 	m.FlagsOut().ForEachIf(
 		func(f flag.Flag) bool {
 			return f.MatchesType(flag.TypeInclude) &&

core/flag/flag.go

@@ -19,6 +19,7 @@ const (
 	TypeCpp
 	TypeCC
 	TypeLinker
+	TypeTransitiveLinker // Only for strict targets to comply with Bazel
 	TypeLinkLibrary
 	TypeInclude
 	TypeIncludeLocal // Helper flag to mark local include dirs

core/linux_cclibs.go

@@ -460,6 +460,15 @@ func (g *linuxGenerator) getCommonLibArgs(m BackendCommonLibraryInterface, ctx b
 		return f.MatchesType(flag.TypeLinkLibrary)
 	}).ToStringSlice()
 
+	m.FlagsInTransitive(ctx).ForEachIf(
+		func(f flag.Flag) bool {
+			return f.MatchesType(flag.TypeTransitiveLinker)
+		},
+		func(f flag.Flag) {
+			ldlibs = append(ldlibs, f.ToString())
+		},
+	)
+
 	if m.IsForwardingSharedLibrary() {
 		ldflags = append(ldflags, tc.GetLinker().KeepUnusedDependencies())
 	} else {

core/strict_binary.go

@@ -2,6 +2,8 @@ package core
 
 import (
 	"github.com/ARM-software/bob-build/core/file"
+	"github.com/ARM-software/bob-build/core/flag"
+	"github.com/ARM-software/bob-build/core/tag"
 	"github.com/google/blueprint"
 )
 
@@ -24,6 +26,39 @@ func (m *ModuleStrictBinary) OutFiles() file.Paths {
 	}
 }
 
+func (m *ModuleStrictBinary) FlagsInTransitive(ctx blueprint.BaseModuleContext) flag.Flags {
+
+	flags := m.ModuleStrictLibrary.FlagsInTransitive(ctx)
+
+	visited := map[string]bool{}
+
+	ctx.VisitDirectDepsIf(
+		func(dep blueprint.Module) bool {
+			name := ctx.OtherModuleName(dep)
+			if _, ok := visited[name]; !ok && ctx.OtherModuleDependencyTag(dep) == tag.SharedTag {
+				visited[name] = true
+				return visited[name]
+			}
+
+			return false
+		},
+		func(child blueprint.Module) {
+			if provider, ok := child.(flag.Provider); ok {
+				linkopts := provider.FlagsOut().Filtered(
+					func(f flag.Flag) bool {
+						return f.MatchesType(flag.TypeTransitiveLinker)
+					},
+				)
+
+				linkopts.ForEach(func(f flag.Flag) {
+					flags = flags.AppendIfUnique(f)
+				})
+			}
+		})
+
+	return flags
+}
+
 func (m *ModuleStrictBinary) GenerateBuildActions(ctx blueprint.ModuleContext) {
 	if isEnabled(m) {
 		getGenerator(ctx).strictBinaryActions(m, ctx)

core/strict_library.go

@@ -33,6 +33,8 @@ type StrictLibraryProps struct {
 	Alwayslink *bool
 	Linkstatic *bool
 
+	Linkopts []string
+
 	Local_defines []string
 	Copts         []string
 	Deps          []string
@@ -160,6 +162,11 @@ func (m *ModuleStrictLibrary) FlagsIn() flag.Flags {
 			Tag:          flag.TypeIncludeLocal | flag.TypeInclude,
 			Factory:      flag.FromIncludePathOwned,
 		},
+		{
+			PropertyName: "Linkopts",
+			Tag:          flag.TypeTransitiveLinker,
+			Factory:      flag.FromStringOwned,
+		},
 	}
 
 	return flag.ParseFromProperties(nil, lut, m.Properties)
@@ -191,6 +198,11 @@ func (m *ModuleStrictLibrary) FlagsOut() flag.Flags {
 			Tag:          flag.TypeIncludeLocal | flag.TypeExported | flag.TypeTransitive | flag.TypeIncludeSystem,
 			Factory:      flag.FromIncludePathOwned,
 		},
+		{
+			PropertyName: "Linkopts",
+			Tag:          flag.TypeTransitiveLinker,
+			Factory:      flag.FromStringOwned,
+		},
 	}
 
 	return flag.ParseFromProperties(nil, lut, m.Properties)

docs/module_types/bob_library.md

@@ -4,7 +4,7 @@
 
 ```bp
 bob_library {
-    name, srcs, hdrs, copts, local_defines, defines, deps
+    name, srcs, hdrs, copts, local_defines, defines, deps, linkopts
 }
 ```
 
@@ -21,3 +21,4 @@ This target replaces `bob_static_library` & `bob_shared_library` to mimic Bazel
 | `local_defines`                                | List of strings; default is `[]`<br>Defines that are local to the module and are not added to modules that depend upon this.                      |
 | `copts`                                        | List of strings; default is `[]`<br>This options are included as cflags in the compile/link commands.                                             |
 | `deps`                                         | List of targets; default is `[]`<br>The list of other libraries to be linked in to the binary target.                                             |
+| [`linkopts`](properties/linkopts.md)           | List of strings; default is `[]`<br>List of additional flags to the linker command.                                                               |

docs/module_types/bob_test.md

@@ -4,7 +4,7 @@
 
 ```bp
 bob_test {
-    name, srcs, hdrs, copts, deps, tags
+    name, srcs, hdrs, copts, deps, tags, linkopts
 }
 ```
 
@@ -26,3 +26,4 @@ Supports:
 | `copts`                                        | List of strings; default is `[]`<br>This options are included as cflags in the compile/link commands. |
 | `deps`                                         | List of targets; default is `[]`<br>The list of other libraries to be linked in to the binary target. |
 | [`tags`](properties/common_properties.md#tags) | List of strings; default is `[]`                                                                      |
+| [`linkopts`](properties/linkopts.md)           | List of strings; default is `[]`<br>List of additional flags to the linker command.                   |

docs/module_types/properties/linkopts.md

@@ -0,0 +1,35 @@
+# Additional linker options
+
+`linkopts` property allows to provide additional linker options. However there is no any filtering or checking for them - they are passed as is.
+
+Depending on the backend, linker options may behave a bit different thus need to be used carefully. Check below how they are applied for particular backends.
+If needed, they can be separated with [features](../../features.md).
+
+## Example
+
+```bp
+bob_library {
+    name: "libname",
+    srcs: ["libname.cpp"],
+
+    builder_android_bp: {
+        linkopts: [
+            "-u fake_android",
+        ],
+    },
+
+    builder_ninja: {
+        linkopts: [
+            "-u fake_linux",
+        ],
+    },
+}
+```
+
+## Linux Backend
+
+`linkopts` options are appended to the end of the linker command in the order specified.
+
+## Android backend
+
+`linkopts` options are directly mapped to Android module's `ldflags` property.

gendiffer/tests/executable/linkopts/app/bplist

@@ -0,0 +1 @@
+build.bp

gendiffer/tests/executable/linkopts/app/build.bp

@@ -0,0 +1,36 @@
+bob_library {
+    name: "libA",
+    srcs: ["libA.cpp"],
+    host_supported: true,
+    build_by_default: true,
+    linkopts: [
+        "-lfoo",
+        "-Wl,--use-me,$$VAR",
+    ],
+}
+
+bob_library {
+    name: "libB",
+    srcs: ["libB.cpp"],
+    host_supported: true,
+    build_by_default: true,
+    linkstatic: false,
+    linkopts: [
+        "-lbar",
+        "-Wl,-Map,output.map",
+    ],
+}
+
+bob_executable {
+    name: "hello",
+    srcs: ["hello.cpp"],
+    deps: [
+        "libA",
+        "libB",
+    ],
+    linkopts: [
+        "-Wl,-Fake,fakeing",
+    ],
+    host_supported: true,
+    build_by_default: true,
+}

gendiffer/tests/executable/linkopts/out/android/Android.bp.out

@@ -0,0 +1,86 @@
+
+genrule {
+    name: "_check_buildbp_updates_redacted",
+    srcs: ["build.bp"],
+    out: ["androidbp_up_to_date"],
+    tool_files: ["scripts/verify_hash.py"],
+    cmd: "python $(location scripts/verify_hash.py) --hash redacted --out $(out) -- $(in)",
+}
+
+cc_binary_host {
+    name: "hello__host",
+    stem: "hello",
+    srcs: ["hello.cpp"],
+    ldflags: [
+        "-Wl,-Fake,fakeing",
+        "-lbar",
+        "-Wl,-Map,output.map",
+    ],
+    shared_libs: ["libB__host"],
+    static_libs: ["libA__host"],
+}
+
+cc_binary {
+    name: "hello__target",
+    stem: "hello",
+    srcs: ["hello.cpp"],
+    ldflags: [
+        "-Wl,-Fake,fakeing",
+        "-lbar",
+        "-Wl,-Map,output.map",
+    ],
+    shared_libs: ["libB__target"],
+    static_libs: ["libA__target"],
+    compile_multilib: "both",
+}
+
+cc_library {
+    name: "libA__host",
+    host_supported: true,
+    device_supported: false,
+    stem: "libA",
+    srcs: ["libA.cpp"],
+    ldflags: [
+        "-lfoo",
+        "-Wl,--use-me,$$VAR",
+    ],
+}
+
+cc_library {
+    name: "libA__target",
+    host_supported: false,
+    device_supported: true,
+    stem: "libA",
+    srcs: ["libA.cpp"],
+    ldflags: [
+        "-lfoo",
+        "-Wl,--use-me,$$VAR",
+    ],
+    compile_multilib: "both",
+}
+
+cc_library {
+    name: "libB__host",
+    host_supported: true,
+    device_supported: false,
+    stem: "libB",
+    srcs: ["libB.cpp"],
+    ldflags: [
+        "-lbar",
+        "-Wl,-Map,output.map",
+    ],
+}
+
+cc_library {
+    name: "libB__target",
+    host_supported: false,
+    device_supported: true,
+    stem: "libB",
+    srcs: ["libB.cpp"],
+    ldflags: [
+        "-lbar",
+        "-Wl,-Map,output.map",
+    ],
+    compile_multilib: "both",
+}
+

gendiffer/tests/executable/linkopts/out/android/expectedExitCode.int

@@ -0,0 +1 @@
+0