From 7df53d5e18cc5b39d9452e4aa3c653d0efa9f65f Mon Sep 17 00:00:00 2001 From: Rune Tynan Date: Mon, 13 Feb 2023 13:39:28 -0500 Subject: [PATCH] Fix metadata encoding and decoding to use the right length --- compiler/rustc_codegen_ssa/src/back/metadata.rs | 7 ++++++- compiler/rustc_metadata/src/locator.rs | 6 +++--- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs index 190cd69a0e9..75daf33db30 100644 --- a/compiler/rustc_codegen_ssa/src/back/metadata.rs +++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs @@ -305,8 +305,13 @@ pub fn create_compressed_metadata_file( symbol_name: &str, ) -> Vec { let mut compressed = rustc_metadata::METADATA_HEADER.to_vec(); - compressed.write_all(&(metadata.raw_data().len() as u32).to_be_bytes()).unwrap(); + // Our length will be backfilled once we're done writing + compressed.write_all(&[0; 4]).unwrap(); FrameEncoder::new(&mut compressed).write_all(metadata.raw_data()).unwrap(); + let meta_len = rustc_metadata::METADATA_HEADER.len(); + let data_len = (compressed.len() - meta_len - 4) as u32; + compressed[meta_len..meta_len + 4].copy_from_slice(&data_len.to_be_bytes()); + let Some(mut file) = create_object_file(sess) else { return compressed.to_vec(); }; diff --git a/compiler/rustc_metadata/src/locator.rs b/compiler/rustc_metadata/src/locator.rs index 285d6e22d47..ea1ba8a9eda 100644 --- a/compiler/rustc_metadata/src/locator.rs +++ b/compiler/rustc_metadata/src/locator.rs @@ -799,14 +799,14 @@ fn get_metadata_section<'p>( } // Length of the compressed stream - this allows linkers to pad the section if they want - let usize_len = core::mem::size_of::(); - let Ok(len_bytes) = <[u8; 4]>::try_from(&buf[header_len..cmp::min(header_len + usize_len, buf.len())]) else { + let u32_len = core::mem::size_of::(); + let Ok(len_bytes) = <[u8; 4]>::try_from(&buf[header_len..cmp::min(header_len + u32_len, buf.len())]) else { return Err(MetadataError::LoadFailure("invalid metadata length found".to_string())); }; let compressed_len = u32::from_be_bytes(len_bytes) as usize; // Header is okay -> inflate the actual metadata - let compressed_bytes = &buf[header_len..compressed_len + header_len]; + let compressed_bytes = &buf[(header_len + u32_len)..(compressed_len + header_len + u32_len)]; debug!("inflating {} bytes of compressed metadata", compressed_bytes.len()); // Assume the decompressed data will be at least the size of the compressed data, so we // don't have to grow the buffer as much.