Re: [edk2-devel] [PATCH v7 2/2] tools_def: add -fno-omit-frame-pointer to GCC48_{IA32,X64}_CC_FLAGS

["Brian J. Johnson" <brian.johnson@hpe.com>]

Gerd,

Sorry, gotta ask:  does this make much difference in the size of the 
compiled code?  That's a constraint on many real-hardware X64 platforms, 
especially for 32-bit code.

Brian J. Johnson

-------- Original Message --------
From: Gerd Hoffmann [mailto:kraxel@redhat.com]
Sent: Wednesday, November 30, 2022 at 3:44 AM
To: devel@edk2.groups.io
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>, Liming Gao 
<gaoliming@byosoft.com.cn>, Erdem Aktas <erdemaktas@google.com>, Pawel 
Polawski <ppolawsk@redhat.com>, Jordan Justen 
<jordan.l.justen@intel.com>, Ard Biesheuvel <ardb+tianocore@kernel.org>, 
Yuwei Chen <yuwei.chen@intel.com>, Tom Lendacky 
<thomas.lendacky@amd.com>, James Bottomley <jejb@linux.ibm.com>, Gerd 
Hoffmann <kraxel@redhat.com>, Oliver Steffen <osteffen@redhat.com>, 
Jiewen Yao <jiewen.yao@intel.com>, Min Xu <min.m.xu@intel.com>, Brijesh 
Singh <brijesh.singh@amd.com>, Bob Feng <bob.c.feng@intel.com>
Subject: [edk2-devel] [PATCH v7 2/2] tools_def: add 
-fno-omit-frame-pointer to GCC48_{IA32,X64}_CC_FLAGS

Fixes problems due to code assuming it runs with frame pointers and thus
updates rbp / ebp registers when switching stacks.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
   BaseTools/Conf/tools_def.template | 4 ++--
   1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/BaseTools/Conf/tools_def.template 
b/BaseTools/Conf/tools_def.template
index 73f95b2a3a9f..f1fd6a003062 100755
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -1888,8 +1888,8 @@ DEFINE GCC_DEPS_FLAGS              = -MMD -MF $@.deps

   DEFINE GCC48_ALL_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) 
-ffunction-sections -fdata-sections -DSTRING_ARRAY_NAME=$(BASE_NAME)Strings
   DEFINE GCC48_IA32_X64_DLINK_COMMON   = -nostdlib 
-Wl,-n,-q,--gc-sections -z common-page-size=0x20
-DEFINE GCC48_IA32_CC_FLAGS           = DEF(GCC48_ALL_CC_FLAGS) -m32 
-march=i586 -malign-double -fno-stack-protector -D EFI32 
-fno-asynchronous-unwind-tables -Wno-address
-DEFINE GCC48_X64_CC_FLAGS            = DEF(GCC48_ALL_CC_FLAGS) -m64 
-fno-stack-protector "-DEFIAPI=__attribute__((ms_abi))" 
-maccumulate-outgoing-args -mno-red-zone -Wno-address -mcmodel=small 
-fpie -fno-asynchronous-unwind-tables -Wno-address
+DEFINE GCC48_IA32_CC_FLAGS           = DEF(GCC48_ALL_CC_FLAGS) -m32 
-march=i586 -malign-double -fno-stack-protector -D EFI32 
-fno-asynchronous-unwind-tables -Wno-address -fno-omit-frame-pointer
+DEFINE GCC48_X64_CC_FLAGS            = DEF(GCC48_ALL_CC_FLAGS) -m64 
-fno-stack-protector "-DEFIAPI=__attribute__((ms_abi))" 
-maccumulate-outgoing-args -mno-red-zone -Wno-address -mcmodel=small 
-fpie -fno-asynchronous-unwind-tables -Wno-address  -fno-omit-frame-pointer
   DEFINE GCC48_IA32_X64_ASLDLINK_FLAGS = 
DEF(GCC48_IA32_X64_DLINK_COMMON) -Wl,--entry,ReferenceAcpiTable -u 
ReferenceAcpiTable
   DEFINE GCC48_IA32_X64_DLINK_FLAGS    = 
DEF(GCC48_IA32_X64_DLINK_COMMON) -Wl,--entry,$(IMAGE_ENTRY_POINT) -u 
$(IMAGE_ENTRY_POINT) 
-Wl,-Map,$(DEST_DIR_DEBUG)/$(BASE_NAME).map,--whole-archive
   DEFINE GCC48_IA32_DLINK2_FLAGS       = 
-Wl,--defsym=PECOFF_HEADER_SIZE=0x220 DEF(GCC_DLINK2_FLAGS_COMMON)

-- 

                                                 Brian

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