| Message ID | 20250430-improve_llvm_building-v1-1-caae96cc6be6@rivosinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | Makefile: Make $(LLVM) more flexible | expand |
On 1 May 2025, at 00:38, Charlie Jenkins <charlie@rivosinc.com> wrote: > > Introduce a way for developers to easily switch between LLVM versions > with LLVM=/path/to/llvm/ and LLVM=-version. This is a useful FreeBSD doesn’t include a hyphen in its version number suffix, you get clang20 etc. In the Linux world where you’ve copied this pattern from verbatim that may well hold, but OpenSBI supports more than just Linux. One could special-case LLVM=1 and treat anything else as a suffix I suppose, though that would be a little weird. Jess > addition to the existing LLVM=1 variable which will select the first > clang and llvm binutils available on the path. > > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> > --- > Makefile | 14 ++++++++++---- > README.md | 12 ++++++++++++ > 2 files changed, 22 insertions(+), 4 deletions(-) > > diff --git a/Makefile b/Makefile > index e90836c7c4ad16c30d4d80649ff8b228413190ad..37d4cf41a2214e0a829f1d4a53f3f4f9ae09ee41 100644 > --- a/Makefile > +++ b/Makefile > @@ -104,10 +104,16 @@ endif > > # Setup compilation commands > ifneq ($(LLVM),) > -CC = clang > -AR = llvm-ar > -LD = ld.lld > -OBJCOPY = llvm-objcopy > +ifneq ($(filter %/,$(LLVM)),) > +LLVM_PREFIX := $(LLVM) > +else ifneq ($(filter -%,$(LLVM)),) > +LLVM_SUFFIX := $(LLVM) > +endif > + > +CC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) > +AR = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX) > +LD = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) > +OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) > else > ifdef CROSS_COMPILE > CC = $(CROSS_COMPILE)gcc > diff --git a/README.md b/README.md > index 2795cc1a5ff0df62d83a4b5c3062ff2b682dbcab..fd40be0b4988815d8d02386271aeaeb787541215 100644 > --- a/README.md > +++ b/README.md > @@ -252,6 +252,18 @@ option with: > make LLVM=1 > ``` > > +To build with a specific version of LLVM, a path to a directory containing the > +LLVM tools can be provided: > +``` > +make LLVM=/path/to/llvm/ > +``` > + > +If you have versioned llvm tools you would like to use, such as `clang-17`, the LLVM variable can > +be set as: > +``` > +make LLVM=-17 > +``` > + > When using Clang, *CROSS_COMPILE* often does not need to be defined unless > using GNU binutils with prefixed binary names. *PLATFORM_RISCV_XLEN* will be > used to infer a default triple to pass to Clang, so if *PLATFORM_RISCV_XLEN* > > --- > base-commit: 316daaf1c299c29ac46e52145f65521f48ec63b5 > change-id: 20250430-improve_llvm_building-cff31918e1a6 > -- > - Charlie > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi
On Thu, May 01, 2025 at 01:04:38AM +0100, Jessica Clarke wrote: > On 1 May 2025, at 00:38, Charlie Jenkins <charlie@rivosinc.com> wrote: > > > > Introduce a way for developers to easily switch between LLVM versions > > with LLVM=/path/to/llvm/ and LLVM=-version. This is a useful > > FreeBSD doesn’t include a hyphen in its version number suffix, you get > clang20 etc. In the Linux world where you’ve copied this pattern from > verbatim that may well hold, but OpenSBI supports more than just Linux. > > One could special-case LLVM=1 and treat anything else as a suffix I > suppose, though that would be a little weird. This pattern not being applicable for all systems doesn't invalidate the usecase for systems that do support it. Developers can still manipulate their PATH to get LLVM=1 to select the clang that they want. - Charlie > > Jess > > > addition to the existing LLVM=1 variable which will select the first > > clang and llvm binutils available on the path. > > > > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> > > --- > > Makefile | 14 ++++++++++---- > > README.md | 12 ++++++++++++ > > 2 files changed, 22 insertions(+), 4 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index e90836c7c4ad16c30d4d80649ff8b228413190ad..37d4cf41a2214e0a829f1d4a53f3f4f9ae09ee41 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -104,10 +104,16 @@ endif > > > > # Setup compilation commands > > ifneq ($(LLVM),) > > -CC = clang > > -AR = llvm-ar > > -LD = ld.lld > > -OBJCOPY = llvm-objcopy > > +ifneq ($(filter %/,$(LLVM)),) > > +LLVM_PREFIX := $(LLVM) > > +else ifneq ($(filter -%,$(LLVM)),) > > +LLVM_SUFFIX := $(LLVM) > > +endif > > + > > +CC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) > > +AR = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX) > > +LD = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) > > +OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) > > else > > ifdef CROSS_COMPILE > > CC = $(CROSS_COMPILE)gcc > > diff --git a/README.md b/README.md > > index 2795cc1a5ff0df62d83a4b5c3062ff2b682dbcab..fd40be0b4988815d8d02386271aeaeb787541215 100644 > > --- a/README.md > > +++ b/README.md > > @@ -252,6 +252,18 @@ option with: > > make LLVM=1 > > ``` > > > > +To build with a specific version of LLVM, a path to a directory containing the > > +LLVM tools can be provided: > > +``` > > +make LLVM=/path/to/llvm/ > > +``` > > + > > +If you have versioned llvm tools you would like to use, such as `clang-17`, the LLVM variable can > > +be set as: > > +``` > > +make LLVM=-17 > > +``` > > + > > When using Clang, *CROSS_COMPILE* often does not need to be defined unless > > using GNU binutils with prefixed binary names. *PLATFORM_RISCV_XLEN* will be > > used to infer a default triple to pass to Clang, so if *PLATFORM_RISCV_XLEN* > > > > --- > > base-commit: 316daaf1c299c29ac46e52145f65521f48ec63b5 > > change-id: 20250430-improve_llvm_building-cff31918e1a6 > > -- > > - Charlie > > > > > > -- > > opensbi mailing list > > opensbi@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/opensbi >
diff --git a/Makefile b/Makefile index e90836c7c4ad16c30d4d80649ff8b228413190ad..37d4cf41a2214e0a829f1d4a53f3f4f9ae09ee41 100644 --- a/Makefile +++ b/Makefile @@ -104,10 +104,16 @@ endif # Setup compilation commands ifneq ($(LLVM),) -CC = clang -AR = llvm-ar -LD = ld.lld -OBJCOPY = llvm-objcopy +ifneq ($(filter %/,$(LLVM)),) +LLVM_PREFIX := $(LLVM) +else ifneq ($(filter -%,$(LLVM)),) +LLVM_SUFFIX := $(LLVM) +endif + +CC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +AR = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX) +LD = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) +OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) else ifdef CROSS_COMPILE CC = $(CROSS_COMPILE)gcc diff --git a/README.md b/README.md index 2795cc1a5ff0df62d83a4b5c3062ff2b682dbcab..fd40be0b4988815d8d02386271aeaeb787541215 100644 --- a/README.md +++ b/README.md @@ -252,6 +252,18 @@ option with: make LLVM=1 ``` +To build with a specific version of LLVM, a path to a directory containing the +LLVM tools can be provided: +``` +make LLVM=/path/to/llvm/ +``` + +If you have versioned llvm tools you would like to use, such as `clang-17`, the LLVM variable can +be set as: +``` +make LLVM=-17 +``` + When using Clang, *CROSS_COMPILE* often does not need to be defined unless using GNU binutils with prefixed binary names. *PLATFORM_RISCV_XLEN* will be used to infer a default triple to pass to Clang, so if *PLATFORM_RISCV_XLEN*
Introduce a way for developers to easily switch between LLVM versions with LLVM=/path/to/llvm/ and LLVM=-version. This is a useful addition to the existing LLVM=1 variable which will select the first clang and llvm binutils available on the path. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> --- Makefile | 14 ++++++++++---- README.md | 12 ++++++++++++ 2 files changed, 22 insertions(+), 4 deletions(-) --- base-commit: 316daaf1c299c29ac46e52145f65521f48ec63b5 change-id: 20250430-improve_llvm_building-cff31918e1a6