From 4e9d858638034246a4ab4595f5497c7393c3bfbf Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 10 Oct 2007 06:29:10 +0000 Subject: [PATCH] From Craig Silverstein: delete the output file first if it exists and is non-empty. --- gold/output.cc | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/gold/output.cc b/gold/output.cc index f217b03ca2..f539deac83 100644 --- a/gold/output.cc +++ b/gold/output.cc @@ -27,6 +27,7 @@ #include #include #include +#include #include #include "parameters.h" @@ -1672,6 +1673,25 @@ Output_file::open(off_t file_size) { this->file_size_ = file_size; + // Unlink the file first; otherwise the open() may fail if the file + // is busy (e.g. it's an executable that's currently being executed). + // + // However, the linker may be part of a system where a zero-length + // file is created for it to write to, with tight permissions (gcc + // 2.95 did something like this). Unlinking the file would work + // around those permission controls, so we only unlink if the file + // has a non-zero size. We also unlink only regular files to avoid + // trouble with directories/etc. + // + // If we fail, continue; this command is merely a best-effort attempt + // to improve the odds for open(). + + // FIXME: unlink the file if it's a symlink, even a symlink to a dir. + // Or do we want to follow the symlink and unlink its target? + struct stat s; + if (::stat(this->name_, &s) == 0 && s.st_size != 0 && S_ISREG(s.st_mode)) + ::unlink(this->name_); + int mode = parameters->output_is_object() ? 0666 : 0777; int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode); if (o < 0) -- 2.34.1