incfs: tolerate either ptrdiff_t or size_t for std::span

The out-of-date std::span in external/libcxx currently uses ptrdiff_t
as the type of size() and the second ctor argument. The C++20 std::span
actually uses size_t for these values instead. Try to accommodate both
versions of std::span until libc++ is upgraded.

Bug: http://b/175635923
Test: treehugger
Change-Id: Idc43f880b6eb21dad79e79fa456847d5865a1ed2

2 files changed, 7 insertions, 4 deletions

diff --git a/services/incremental/BinderIncrementalService.cpp b/services/incremental/BinderIncrementalService.cpp
index 2f031bfe4f3f..45ca5cd84e39 100644
--- a/services/incremental/BinderIncrementalService.cpp
+++ b/services/incremental/BinderIncrementalService.cpp
@@ -216,7 +216,10 @@ static std::span<const uint8_t> toSpan(const ::std::optional<::std::vector<uint8
     if (!content) {
         return {};
     }
-    return {content->data(), (int)content->size()};
+    // TODO(b/175635923): Replace with {content->data(), content->size()} after libc++ is upgraded.
+    // The type of the second std::span ctor param changed from ptrdiff_t to size_t between the old
+    // libc++ and the finalized C++20.
+    return std::span<const uint8_t>(content->data(), content->size());
 }
 
 binder::Status BinderIncrementalService::makeFile(
diff --git a/services/incremental/IncrementalService.cpp b/services/incremental/IncrementalService.cpp
index a49577b21957..6196c49c88ce 100644
--- a/services/incremental/IncrementalService.cpp
+++ b/services/incremental/IncrementalService.cpp
@@ -1166,11 +1166,11 @@ int IncrementalService::makeFile(StorageId storage, std::string_view path, int m
     if (!ifs) {
         return -EINVAL;
     }
-    if (data.size() > params.size) {
+    if ((IncFsSize)data.size() > params.size) {
         LOG(ERROR) << "Bad data size - bigger than file size";
         return -EINVAL;
     }
-    if (!data.empty() && data.size() != params.size) {
+    if (!data.empty() && (IncFsSize)data.size() != params.size) {
         // Writing a page is an irreversible operation, and it can't be updated with additional
         // data later. Check that the last written page is complete, or we may break the file.
         if (!isPageAligned(data.size())) {
@@ -3188,7 +3188,7 @@ binder::Status IncrementalService::IncrementalServiceConnector::setStorageParams
 }
 
 FileId IncrementalService::idFromMetadata(std::span<const uint8_t> metadata) {
-    return IncFs_FileIdFromMetadata({(const char*)metadata.data(), metadata.size()});
+    return IncFs_FileIdFromMetadata({(const char*)metadata.data(), (IncFsSize)metadata.size()});
 }
 
 } // namespace android::incremental