diff --git a/rust/compiler.go b/rust/compiler.go index de59f39ac..04fef3580 100644 --- a/rust/compiler.go +++ b/rust/compiler.go @@ -65,7 +65,11 @@ const ( ) type BaseCompilerProperties struct { - // path to the source file that is the main entry point of the program (e.g. main.rs or lib.rs) + // path to the source file that is the main entry point of the program (e.g. main.rs or lib.rs). + // Only a single source file can be defined. Modules which generate source can be included by prefixing + // the module name with ":", for example ":libfoo_bindgen" + // + // If no source file is defined, a single generated source module can be defined to be used as the main source. Srcs []string `android:"path,arch_variant"` // name of the lint set that should be used to validate this module. @@ -420,12 +424,18 @@ func srcPathFromModuleSrcs(ctx ModuleContext, srcs []string) (android.Path, andr srcIndex = i } } - if numSrcs != 1 { + if numSrcs > 1 { ctx.PropertyErrorf("srcs", incorrectSourcesError) } + + // If a main source file is not provided we expect only a single SourceProvider module to be defined + // within srcs, with the expectation that the first source it provides is the entry point. if srcIndex != 0 { ctx.PropertyErrorf("srcs", "main source file must be the first in srcs") + } else if numSrcs > 1 { + ctx.PropertyErrorf("srcs", "only a single generated source module can be defined without a main source file.") } + paths := android.PathsForModuleSrc(ctx, srcs) return paths[srcIndex], paths[1:] }