Hello,
The following compilation condition in OpenPlatformPkg\Platforms\ARM\Juno\AcpiTables\Fadt.aslc
#if ARM_JUNO_ACPI_5_0
causes the GCC error listed below
k:\edk2\OpenPlatformPkg\Platforms\ARM\Juno\AcpiTables\Fadt.aslc:76:22: error: #if with no expression
#if ARM_JUNO_ACPI_5_0
^
when ARM_JUNO_ACPI_5_0 macro is defined in edk2\ArmPlatformPkg\ArmJunoPkg\Include\ArmPltaform.h:
#define ARM_JUNO_ACPI_5_0
To fix the bug
#if ARM_JUNO_ACPI_5_0
should be replaced with
#ifdef ARM_JUNO_ACPI_5_0
(also see the previous usage on line #20 in the same file)
Alexei.