llvm_7: backport patch for musl 1.2.4

pkgs/development/compilers/llvm/7/llvm/default.nix

@@ -108,6 +108,8 @@ in stdenv.mkDerivation (rec {
       sha256 = "0zjfjgavqzi2ypqwqnlvy6flyvdz8hi1anwv0ybwnm2zqixg7za3";
       stripLen = 1;
     })
+
+    ../../llvm-7-musl.patch
   ] ++ lib.optional enablePolly ./gnu-install-dirs-polly.patch;
 
   postPatch = optionalString stdenv.isDarwin ''

pkgs/development/compilers/llvm/llvm-7-musl.patch

@@ -0,0 +1,92 @@
+From 8c747d3157df2830eed9205e7caf1203b345de17 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Sat, 4 Feb 2023 13:54:41 -0800
+Subject: [PATCH] cmake: Enable 64bit off_t on 32bit glibc systems
+
+Pass -D_FILE_OFFSET_BITS=64 to compiler flags on 32bit glibc based
+systems. This will make sure that 64bit versions of LFS functions are
+used e.g. seek will behave same as lseek64. Also revert [1] partially
+because this added a cmake test to detect lseek64 but then forgot to
+pass the needed macro to actual compile, this test was incomplete too
+since libc implementations like musl has 64bit off_t by default on 32bit
+systems and does not bundle[2] -D_LARGEFILE64_SOURCE under -D_GNU_SOURCE
+like glibc, which means the compile now fails on musl because the cmake
+check passes but we do not have _LARGEFILE64_SOURCE defined. Using the
+*64 function was transitional anyways so use -D_FILE_OFFSET_BITS=64
+instead
+
+[1] https://github.com/llvm/llvm-project/commit/8db7e5e4eed4c4e697dc3164f2c9351d8c3e942b
+[2] https://git.musl-libc.org/cgit/musl/commit/?id=25e6fee27f4a293728dd15b659170e7b9c7db9bc
+
+Reviewed By: MaskRay
+
+Differential Revision: https://reviews.llvm.org/D139752
+
+(cherry picked from commit 5cd554303ead0f8891eee3cd6d25cb07f5a7bf67)
+---
+ cmake/config-ix.cmake              | 13 ++++++++++---
+ include/llvm/Config/config.h.cmake |  3 ---
+ lib/Support/raw_ostream.cpp        |  2 --
+ 3 files changed, 10 insertions(+), 8 deletions(-)
+
+diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
+index 18977d9950ff..b558aa83fa62 100644
+--- a/cmake/config-ix.cmake
++++ b/cmake/config-ix.cmake
+@@ -197,9 +197,6 @@ check_symbol_exists(posix_fallocate fcntl.h HAVE_POSIX_FALLOCATE)
+ if( HAVE_SIGNAL_H AND NOT LLVM_USE_SANITIZER MATCHES ".*Address.*" AND NOT APPLE )
+   check_symbol_exists(sigaltstack signal.h HAVE_SIGALTSTACK)
+ endif()
+-set(CMAKE_REQUIRED_DEFINITIONS "-D_LARGEFILE64_SOURCE")
+-check_symbol_exists(lseek64 "sys/types.h;unistd.h" HAVE_LSEEK64)
+-set(CMAKE_REQUIRED_DEFINITIONS "")
+ check_symbol_exists(mallctl malloc_np.h HAVE_MALLCTL)
+ check_symbol_exists(mallinfo malloc.h HAVE_MALLINFO)
+ check_symbol_exists(malloc_zone_statistics malloc/malloc.h
+@@ -237,6 +234,16 @@ if( PURE_WINDOWS )
+   check_function_exists(__main HAVE___MAIN)
+   check_function_exists(__cmpdi2 HAVE___CMPDI2)
+ endif()
++
++check_symbol_exists(__GLIBC__ stdio.h LLVM_USING_GLIBC)
++if( LLVM_USING_GLIBC )
++# enable 64bit off_t on 32bit systems using glibc
++  if (CMAKE_SIZEOF_VOID_P EQUAL 4)
++    add_compile_definitions(_FILE_OFFSET_BITS=64)
++    list(APPEND CMAKE_REQUIRED_DEFINITIONS "-D_FILE_OFFSET_BITS=64")
++  endif()
++endif()
++
+ if( HAVE_DLFCN_H )
+   if( HAVE_LIBDL )
+     list(APPEND CMAKE_REQUIRED_LIBRARIES dl)
+diff --git a/include/llvm/Config/config.h.cmake b/include/llvm/Config/config.h.cmake
+index e934617d7ec7..3c39c373b3c1 100644
+--- a/include/llvm/Config/config.h.cmake
++++ b/include/llvm/Config/config.h.cmake
+@@ -112,9 +112,6 @@
+ /* Define to 1 if you have the <link.h> header file. */
+ #cmakedefine HAVE_LINK_H ${HAVE_LINK_H}
+ 
+-/* Define to 1 if you have the `lseek64' function. */
+-#cmakedefine HAVE_LSEEK64 ${HAVE_LSEEK64}
+-
+ /* Define to 1 if you have the <mach/mach.h> header file. */
+ #cmakedefine HAVE_MACH_MACH_H ${HAVE_MACH_MACH_H}
+ 
+diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
+index 038ad00bd608..921ab8409008 100644
+--- a/lib/Support/raw_ostream.cpp
++++ b/lib/Support/raw_ostream.cpp
+@@ -677,8 +677,6 @@ uint64_t raw_fd_ostream::seek(uint64_t off) {
+   flush();
+ #ifdef _WIN32
+   pos = ::_lseeki64(FD, off, SEEK_SET);
+-#elif defined(HAVE_LSEEK64)
+-  pos = ::lseek64(FD, off, SEEK_SET);
+ #else
+   pos = ::lseek(FD, off, SEEK_SET);
+ #endif
+-- 
+2.37.1
+