Hi,

When build ovmf with the latest two commits of master branch, we meet error on Red Hat 7.6 with gcc version 4.8.5, but succeed on Red Hat 8.0 with gcc version 8.2.1.

Steps:

git clone https://github.com/tianocore/edk2.git

cd edk2

git submodule init

git submodule update –recursive

OvmfPkg/build.sh -a X64 -n 64

Error log:

…….

/home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c:641:50: error: ‘PageMapLevel5Entry’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

   PAGE_MAP_AND_DIRECTORY_POINTER                *PageMapLevel5Entry;

                                                  ^

cc1: all warnings being treated as errors

"objcopy"  /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe/DEBUG/PciHostBridgeDxe.dll

"GenFw" -e UEFI_DRIVER -o /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBusDxe/OUTPUT/XenBusDxe.efi /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBusDxe/DEBUG/XenBusDxe.dll

make: *** [/home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/MdeModulePkg/Core/DxeIplPeim/DxeIpl/OUTPUT/X64/VirtualMemory.obj] Error 1

cp -f /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBusDxe/OUTPUT/XenBusDxe.efi /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBusDxe/DEBUG

build.py...

: error 7000: Failed to execute command

        make tbuild [/home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/MdeModulePkg/Core/DxeIplPeim/DxeIpl]

build.py...

: error F002: Failed to build module

        /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf [X64, GCC48, DEBUG]

- Failed -

Build end time: 08:46:33, Aug.13 2019

Build total time: 00:01:15

GCC:

gcc --version

gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36)

Copyright (C) 2015 Free Software Foundation, Inc.

This is free software; see the source for copying conditions.  There is NO

warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Thanks,

Fan