Re: [edk2-devel] [PATCH v4 01/10] BaseTools: add BASETOOLS define

["Gerd Hoffmann" <kraxel@redhat.com>]

  Hi,

> > Works (test patch below for reference).
> 
> Excellent, thanks for confirming.
> 
> So I think we should add this for all Clang configurations that enable
> PIE codegen. We don't support GCC < 5 anyway so this gives us uniform
> behavior for all ELF based toolchains used for x86.

Which seems to be only X64, so the patch below should be about right
(doing s/-fpie/-fpie -fdirect-access-external-data/)?

take care,
  Gerd

>From 964965d9da66235e3a29d3735ebdf6c9544b86c3 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 22 May 2023 16:35:54 +0200
Subject: [PATCH 1/1] BaseTools: add -fdirect-access-external-data to clang pie
 builds

Tell clang to not use external (via got) references for data access.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 BaseTools/Conf/tools_def.template | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index 503a6687c1f0..92421e3d0118 100755
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -1921,15 +1921,15 @@ NOOPT_CLANGDWARF_IA32_DLINK2_FLAGS     = DEF(CLANGDWARF_IA32_DLINK2_FLAGS) -O0 -
 *_CLANGDWARF_X64_ASLPP_FLAGS          = DEF(GCC_ASLPP_FLAGS) DEF(CLANGDWARF_X64_TARGET)
 *_CLANGDWARF_X64_VFRPP_FLAGS          = DEF(GCC_VFRPP_FLAGS) DEF(CLANGDWARF_X64_TARGET)
 
-DEBUG_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANGDWARF_X64_TARGET) -g
+DEBUG_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -fdirect-access-external-data -Oz -flto DEF(CLANGDWARF_X64_TARGET) -g
 DEBUG_CLANGDWARF_X64_DLINK_FLAGS      = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -flto -Wl,-O3 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
 DEBUG_CLANGDWARF_X64_DLINK2_FLAGS     = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O3 -fuse-ld=lld
 
-RELEASE_CLANGDWARF_X64_CC_FLAGS       = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANGDWARF_X64_TARGET)
+RELEASE_CLANGDWARF_X64_CC_FLAGS       = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -fdirect-access-external-data -Oz -flto DEF(CLANGDWARF_X64_TARGET)
 RELEASE_CLANGDWARF_X64_DLINK_FLAGS    = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -flto -Wl,-O3 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
 RELEASE_CLANGDWARF_X64_DLINK2_FLAGS   = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O3 -fuse-ld=lld
 
-NOOPT_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -O0 DEF(CLANGDWARF_X64_TARGET) -g
+NOOPT_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -fdirect-access-external-data -O0 DEF(CLANGDWARF_X64_TARGET) -g
 NOOPT_CLANGDWARF_X64_DLINK_FLAGS      = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -Wl,-O0 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
 NOOPT_CLANGDWARF_X64_DLINK2_FLAGS     = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O0 -fuse-ld=lld
 
-- 
2.40.1