From 1769cb478a294bd2c1c6ac4ee22e86ec999d37e4 Mon Sep 17 00:00:00 2001 From: Daniel Kiper Date: Thu, 10 Mar 2022 18:49:35 +0100 Subject: [PATCH] conf/i386-cygwin-img-ld: Do not discard .data and .edata sections MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit $ ./configure --target=i686-w64-mingw32 --with-platform=efi --host=i686-w64-mingw32 [...] checking if __bss_start is defined by the compiler... no checking if edata is defined by the compiler... no checking if _edata is defined by the compiler... no configure: error: none of __bss_start, edata or _edata is defined This happens on machines with quite recent ld due to an error: `edata' referenced in section `.text' of /tmp/cc72w9E4.o: defined in discarded section `.data' of conftest.exe collect2: error: ld returned 1 exit status So, we have to tell linker to not discard .data and .edata sections. The trick comes from ld documentation: 3.6.7 Output Section Discarding The linker will not normally create output sections with no contents. This is for convenience when referring to input sections that may or may not be present in any of the input files. For example: .foo : { *(.foo) } will only create a ‘.foo’ section in the output file if there is a ‘.foo’ section in at least one input file, and if the input sections are not all empty. Other link script directives that allocate space in an output section will also create the output section. So too will assignments to dot even if the assignment does not create space, except for ‘. = 0’, ‘. = . + 0’, ‘. = sym’, ‘. = . + sym’ and ‘. = ALIGN (. != 0, expr, 1)’ when ‘sym’ is an absolute symbol of value 0 defined in the script. This allows you to force output of an empty section with ‘. = .’. This change does not impact generated binaries because the conf/i386-cygwin-img-ld.sc linker script is used only when you run configure. Signed-off-by: Daniel Kiper Reviewed-by: Robbie Harwood --- conf/i386-cygwin-img-ld.sc | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/conf/i386-cygwin-img-ld.sc b/conf/i386-cygwin-img-ld.sc index 3ac26fcce..578da91b0 100644 --- a/conf/i386-cygwin-img-ld.sc +++ b/conf/i386-cygwin-img-ld.sc @@ -14,6 +14,8 @@ SECTIONS { __data_start__ = . ; *(.data) + /* Do not discard this section. */ + . = . ; __data_end__ = . ; __rdata_start__ = . ; *(.rdata) @@ -34,6 +36,8 @@ SECTIONS .edata : { *(.edata) + /* Do not discard this section. */ + . = . ; end = . ; _end = . ; __end = . ; -- 2.47.3