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| author | Fangrui Song <maskray@google.com> | 2020-05-04 09:45:41 -0700 |
|---|---|---|
| committer | Fangrui Song <maskray@google.com> | 2020-05-05 08:11:58 -0700 |
| commit | 9d53db2aa098ca5136c352c38710ea48bf078e7a (patch) | |
| tree | c4385325c7e8cb2914f553a112d0f29ec7ec6941 /llvm/lib/Support/FileOutputBuffer.cpp | |
| parent | 47f5066553240b1559eed06706688ed8cce56fe7 (diff) | |
| download | llvm-9d53db2aa098ca5136c352c38710ea48bf078e7a.zip llvm-9d53db2aa098ca5136c352c38710ea48bf078e7a.tar.gz llvm-9d53db2aa098ca5136c352c38710ea48bf078e7a.tar.bz2 | |
[Support] Allow FileOutputBuffer::create to create an empty file
Size==0 triggers `assert(Size != 0)` in mapped_file_region::init.
I plan to use an empty file in D79339 (llvm-objcopy --dump-section).
According to POSIX, "If len is zero, mmap() shall fail and no mapping
shall be established." Just specialize case Size=0 to use
createInMemoryBuffer.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D79338
Diffstat (limited to 'llvm/lib/Support/FileOutputBuffer.cpp')
| -rw-r--r-- | llvm/lib/Support/FileOutputBuffer.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Support/FileOutputBuffer.cpp b/llvm/lib/Support/FileOutputBuffer.cpp index 0a5306f..ec12820 100644 --- a/llvm/lib/Support/FileOutputBuffer.cpp +++ b/llvm/lib/Support/FileOutputBuffer.cpp @@ -172,6 +172,10 @@ FileOutputBuffer::create(StringRef Path, size_t Size, unsigned Flags) { if (Flags & F_executable) Mode |= fs::all_exe; + // If Size is zero, don't use mmap which will fail with EINVAL. + if (Size == 0) + return createInMemoryBuffer(Path, Size, Mode); + fs::file_status Stat; fs::status(Path, Stat); |