Re: [PATCH 1/2] BaseTools/tools_def GCC: ARM/AARCH64: replace -save-temps with -pipe

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 20 June 2017 at 21:28, Laszlo Ersek <lersek@redhat.com> wrote:
> On 06/20/17 20:43, Ard Biesheuvel wrote:
>> For historical reasons, GCC builds for ARM and AARCH64 pass the
>> -save-temps command line option to GCC, which instructs the compiler
>> to preserve intermediate files, i.e., preprocessor output and generated
>> assembler. Given that this clutters up the Build directory, and slows
>> down the build, let's replace it with -pipe, which explicitly tells the
>> compiler to keep all intermediate representations in memory only.
>>
>> Contributed-under: TianoCore Contribution Agreement 1.0
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> ---
>>  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 04a1bcb210ab..7a58ce365ed2 100755
>> --- a/BaseTools/Conf/tools_def.template
>> +++ b/BaseTools/Conf/tools_def.template
>> @@ -4399,7 +4399,7 @@ DEFINE GCC46_X64_DLINK_FLAGS         = DEF(GCC45_X64_DLINK_FLAGS)
>>  DEFINE GCC46_X64_DLINK2_FLAGS        = DEF(GCC45_X64_DLINK2_FLAGS)
>>  DEFINE GCC46_ASM_FLAGS               = DEF(GCC45_ASM_FLAGS)
>>  DEFINE GCC46_ARM_ASM_FLAGS           = $(ARCHASM_FLAGS) $(PLATFORM_FLAGS) DEF(GCC_ASM_FLAGS) -mlittle-endian
>> -DEFINE GCC46_ARM_CC_FLAGS            = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) DEF(GCC_ARM_CC_FLAGS) -fstack-protector -mword-relocations -save-temps
>> +DEFINE GCC46_ARM_CC_FLAGS            = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) DEF(GCC_ARM_CC_FLAGS) -fstack-protector -mword-relocations -pipe
>>  DEFINE GCC46_ARM_CC_XIPFLAGS         = -D__ARM_FEATURE_UNALIGNED=0
>>  DEFINE GCC46_ARM_DLINK_FLAGS         = DEF(GCC_ARM_DLINK_FLAGS) -Wl,--oformat=elf32-littlearm
>>  DEFINE GCC46_ARM_DLINK2_FLAGS        = DEF(GCC_DLINK2_FLAGS_COMMON) -Wl,--defsym=PECOFF_HEADER_SIZE=0x220
>> @@ -4418,7 +4418,7 @@ DEFINE GCC47_ARM_ASM_FLAGS           = DEF(GCC46_ARM_ASM_FLAGS)
>>  DEFINE GCC47_AARCH64_ASM_FLAGS       = $(ARCHASM_FLAGS) $(PLATFORM_FLAGS) DEF(GCC_ASM_FLAGS) -mlittle-endian
>>  DEFINE GCC47_ARM_CC_FLAGS            = DEF(GCC46_ARM_CC_FLAGS)
>>  DEFINE GCC47_ARM_CC_XIPFLAGS         = DEF(GCC_ARM_CC_XIPFLAGS)
>> -DEFINE GCC47_AARCH64_CC_FLAGS        = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) -mcmodel=large DEF(GCC_AARCH64_CC_FLAGS) -save-temps
>> +DEFINE GCC47_AARCH64_CC_FLAGS        = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) -mcmodel=large DEF(GCC_AARCH64_CC_FLAGS) -pipe
>>  DEFINE GCC47_AARCH64_CC_XIPFLAGS     = DEF(GCC_AARCH64_CC_XIPFLAGS)
>>  DEFINE GCC47_ARM_DLINK_FLAGS         = DEF(GCC46_ARM_DLINK_FLAGS)
>>  DEFINE GCC47_ARM_DLINK2_FLAGS        = DEF(GCC46_ARM_DLINK2_FLAGS)
>> @@ -4462,7 +4462,7 @@ DEFINE GCC49_ARM_ASM_FLAGS           = DEF(GCC48_ARM_ASM_FLAGS)
>>  DEFINE GCC49_AARCH64_ASM_FLAGS       = DEF(GCC48_AARCH64_ASM_FLAGS)
>>  DEFINE GCC49_ARM_CC_FLAGS            = DEF(GCC48_ARM_CC_FLAGS)
>>  DEFINE GCC49_ARM_CC_XIPFLAGS         = DEF(GCC48_ARM_CC_XIPFLAGS)
>> -DEFINE GCC49_AARCH64_CC_FLAGS        = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) DEF(GCC44_ALL_CC_FLAGS) DEF(GCC_AARCH64_CC_FLAGS) -save-temps
>> +DEFINE GCC49_AARCH64_CC_FLAGS        = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) DEF(GCC44_ALL_CC_FLAGS) DEF(GCC_AARCH64_CC_FLAGS) -pipe
>>  DEFINE GCC49_AARCH64_CC_XIPFLAGS     = DEF(GCC48_AARCH64_CC_XIPFLAGS)
>>  DEFINE GCC49_ARM_DLINK_FLAGS         = DEF(GCC48_ARM_DLINK_FLAGS)
>>  DEFINE GCC49_ARM_DLINK2_FLAGS        = DEF(GCC48_ARM_DLINK2_FLAGS)
>>
>
> "-pipe" isn't used anywhere else in "tools_def.template". Can we imagine
> a platform where cross-compiling to aarch64 with gcc works otherwise,
> but "-pipe" might break that? Cygwin perhaps? (No clue, honestly.)
>
> For consistency with the rest of "tools_def.template", I'd suggest
> simply dropping "-save-temps", and thinking about "-pipe" separately
> (and then for all the GCC toolchains and for all arches). But, I don't
> feel particularly strongly about this.
>

Yeah, that's a fair point. The fact that -save-temps is specific to
ARM does not mean we should perpetuate that with -pipe.

Leif, if you agree, I will drop the addition of -pipe from this patch,
and we can revisit it later for all GCC flavors.

-- 
Ard.