I've been working on a compiler for a language of mine and wanted to utilize the LLVM Support Library CommandLine to handle argument parsing.
I have only added two simple declarations:
static cl::opt<std::string>
OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
static cl::list<std::string>
InputFilenames("i", cl::desc("Input files"), cl::value_desc("filenames"), cl::OneOrMore);
I then add the usual call in main:
int main(int argc, char *argv[])
{
cl::ParseCommandLineOptions(argc, argv, " My compiler\n");
...
The problem is very apparent when passing -help to my program:
General options:
-aarch64-neon-syntax - Choose style of NEON code to emit from AArch64 backend:
=generic - Emit generic NEON assembly
=apple - Emit Apple-style NEON assembly
-cppfname=<function name> - Specify the name of the generated function
-cppfor=<string> - Specify the name of the thing to generate
-cppgen - Choose what kind of output to generate
=program - Generate a complete program
=module - Generate a module definition
=contents - Generate contents of a module
=function - Generate a function definition
=functions - Generate all function definitions
=inline - Generate an inline function
=variable - Generate a variable definition
=type - Generate a type definition
-debugger-tune - Tune debug info for a particular debugger
=gdb - gdb
=lldb - lldb
=sce - SCE targets (e.g. PS4)
-disable-spill-fusing - Disable fusing of spill code into instructions
-enable-implicit-null-checks - Fold null checks into faulting memory operations
-enable-load-pre -
-enable-objc-arc-opts - enable/disable all ARC Optimizations
-enable-scoped-noalias -
-enable-tbaa -
-exhaustive-register-search - Exhaustive Search for registers bypassing the depth and interference cutoffs of last chance recoloring
-gpsize=<uint> - Global Pointer Addressing Size. The default size is 8.
-i=<filenames> - Input files
-imp-null-check-page-size=<uint> - The page size of the target in bytes
-join-liveintervals - Coalesce copies (default=true)
-limit-float-precision=<uint> - Generate low-precision inline sequences for some float libcalls
-merror-missing-parenthesis - Error for missing parenthesis around predicate registers
-merror-noncontigious-register - Error for register names that aren't contigious
-mfuture-regs - Enable future registers
-mips16-constant-islands - Enable mips16 constant islands.
-mips16-hard-float - Enable mips16 hard float.
-mno-compound - Disable looking for compound instructions for Hexagon
-mno-ldc1-sdc1 - Expand double precision loads and stores to their single precision counterparts
-mno-pairing - Disable looking for duplex instructions for Hexagon
-mwarn-missing-parenthesis - Warn for missing parenthesis around predicate registers
-mwarn-noncontigious-register - Warn for register names that arent contigious
-mwarn-sign-mismatch - Warn for mismatching a signed and unsigned value
-nvptx-sched4reg - NVPTX Specific: schedule for register pressue
-o=<filename> - Output filename
-print-after-all - Print IR after each pass
-print-before-all - Print IR before each pass
-print-machineinstrs=<pass-name> - Print machine instrs
-regalloc - Register allocator to use
=default - pick register allocator based on -O option
=fast - fast register allocator
=greedy - greedy register allocator
=pbqp - PBQP register allocator
-rewrite-map-file=<filename> - Symbol Rewrite Map
-rng-seed=<seed> - Seed for the random number generator
-stackmap-version=<int> - Specify the stackmap encoding version (default = 1)
-stats - Enable statistics output from program (available with Asserts)
-time-passes - Time each pass, printing elapsed time for each on exit
-verify-debug-info -
-verify-dom-info - Verify dominator info (time consuming)
-verify-loop-info - Verify loop info (time consuming)
-verify-regalloc - Verify during register allocation
-verify-region-info - Verify region info (time consuming)
-verify-scev - Verify ScalarEvolution's backedge taken counts (slow)
-x86-asm-syntax - Choose style of code to emit from X86 backend:
=att - Emit AT&T-style assembly
=intel - Emit Intel-style assembly
Generic Options:
-help - Display available options (-help-hidden for more)
-help-list - Display list of available options (-help-list-hidden for more)
-version - Display the version of this program
I would obviously like to cut down the noise to show only the relevant command line options I have exposed.
I realize the CommandLine utility is utilizing global variables and template metaprogramming and my problem is probably due to linking with LLVM statically.
I have found several links that seem to touch on the issue, but nothing concrete as a solution other then possibly dynamically linking to LLVM.
I am running on OS X El Capitan Version 10.11.1
I installed llvm as follows:
git clone http://llvm.org/git/llvm.git
git clone http://llvm.org/git/clang.git llvm/tools/clang
git clone http://llvm.org/git/clang-tools-extra.git llvm/tools/clang/tools/extra
git clone http://llvm.org/git/compiler-rt.git llvm/projects/compiler-rt
git clone http://llvm.org/git/libcxx.git llvm/projects/libcxx
git clone http://llvm.org/git/libcxxabi.git llvm/projects/libcxxabi
mkdir build_llvm
cd build_llvm && cmake -G "Unix Makefiles" -DCMAKE_INSTALL_PREFIX=prefix=/usr/local/llvm ../llvm
make
The relevant portions of my Makefile:
LLVMCONFIG = llvm-config
CPPFLAGS = `$(LLVMCONFIG) --cxxflags` -std=c++11
LDFLAGS = `$(LLVMCONFIG) --ldflags` -lpthread -ldl -lz -lncurses -rdynamic
LIBS = `$(LLVMCONFIG) --libs`
%.o: %.cpp
clang++ -I /usr/local/llvm/include -c $(CPPFLAGS) $< -o $@
mycompiler: $(OBJECTS)
clang++ -I /usr/local/llvm/include -g $^ $(LIBS) $(LDFLAGS) -o $@
As far as I can see, the best you can do is to put all of your options into particular categories and use void llvm::cl::HideUnrelatedOptions(ArrayRef Categories) (or cl::HideUnrelatedOptions(cl::OptionCategory & Category) if you have only a single category). The documentation indicates that clang uses it to get control over the command line options, though I haven't checked in the clang source to see if that is really true.