[Support] Change zlib::compress to return void

With a sufficiently large output buffer, the only failure is Z_MEM_ERROR.
Check it and call the noreturn report_bad_alloc_error if applicable.
resize_for_overwrite may call report_bad_alloc_error as well.

Now that there is no other error type, we can replace the return type with void
and simplify call sites.

Reviewed By: ikudrin

Differential Revision: https://reviews.llvm.org/D121512

1 files changed, 7 insertions, 5 deletions

diff --git a/llvm/lib/Support/Compression.cpp b/llvm/lib/Support/Compression.cpp
index ccf6ef4..983a6348 100644
--- a/llvm/lib/Support/Compression.cpp
+++ b/llvm/lib/Support/Compression.cpp
@@ -46,18 +46,20 @@ static StringRef convertZlibCodeToString(int Code) {
 
 bool zlib::isAvailable() { return true; }
 
-Error zlib::compress(StringRef InputBuffer,
-                     SmallVectorImpl<char> &CompressedBuffer, int Level) {
+void zlib::compress(StringRef InputBuffer,
+                    SmallVectorImpl<char> &CompressedBuffer, int Level) {
   unsigned long CompressedSize = ::compressBound(InputBuffer.size());
   CompressedBuffer.resize_for_overwrite(CompressedSize);
   int Res =
       ::compress2((Bytef *)CompressedBuffer.data(), &CompressedSize,
                   (const Bytef *)InputBuffer.data(), InputBuffer.size(), Level);
+  if (Res == Z_MEM_ERROR)
+    report_bad_alloc_error("Allocation failed");
+  assert(Res == Z_OK);
   // Tell MemorySanitizer that zlib output buffer is fully initialized.
   // This avoids a false report when running LLVM with uninstrumented ZLib.
   __msan_unpoison(CompressedBuffer.data(), CompressedSize);
   CompressedBuffer.truncate(CompressedSize);
-  return Res ? createError(convertZlibCodeToString(Res)) : Error::success();
 }
 
 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
@@ -87,8 +89,8 @@ uint32_t zlib::crc32(StringRef Buffer) {
 
 #else
 bool zlib::isAvailable() { return false; }
-Error zlib::compress(StringRef InputBuffer,
-                     SmallVectorImpl<char> &CompressedBuffer, int Level) {
+void zlib::compress(StringRef InputBuffer,
+                    SmallVectorImpl<char> &CompressedBuffer, int Level) {
   llvm_unreachable("zlib::compress is unavailable");
 }
 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,