clangHelp.log

OVERVIEW: clang LLVM compiler

USAGE: clang [options] <inputs>

OPTIONS:
  -###                    Print (but do not run) the commands to run for this compilation
  --analyze               Run the static analyzer
  -arcmt-migrate-emit-errors
                          Emit ARC errors even if the migrator can fix them
  -arcmt-migrate-report-output <value>
                          Output path for the plist report
  --cuda-device-only      Do device-side CUDA compilation only
  --cuda-host-only        Do host-side CUDA compilation only
  --cuda-path=<value>     CUDA installation path
  -cxx-isystem <directory>
                          Add directory to the C++ SYSTEM include search path
  -c                      Only run preprocess, compile, and assemble steps
  -dD                     Print macro definitions in -E mode in addition to normal output
  -dependency-dot <value> Filename to write DOT-formatted header dependencies to
  -dependency-file <value>
                          Filename (or -) to write dependency output to
  -dM                     Print macro definitions in -E mode instead of normal output
  -emit-ast               Emit Clang AST files for source inputs
  -emit-llvm              Use the LLVM representation for assembler and object files
  -E                      Only run the preprocessor
  -faltivec               Enable AltiVec vector initializer syntax
  -fansi-escape-codes     Use ANSI escape codes for diagnostics
  -fapinotes-cache-path=<directory>
                          Specify the API notes cache path
  -fapinotes              Enable external API notes support
  -fapple-kext            Use Apple's kernel extensions ABI
  -fapple-pragma-pack     Enable Apple gcc-compatible #pragma pack handling
  -fapplication-extension Restrict code to those available for App Extensions
  -fblocks                Enable the 'blocks' language feature
  -fborland-extensions    Accept non-standard constructs supported by the Borland compiler
  -fbuild-session-file=<file>
                          Use the last modification time of <file> as the build session timestamp
  -fbuild-session-timestamp=<time since Epoch in seconds>
                          Time when the current build session started
  -fcolor-diagnostics     Use colors in diagnostics
  -fcomment-block-commands=<arg>
                          Treat each comma separated argument in <arg> as a documentation comment block command
  -fcoverage-mapping      Generate coverage mapping to enable code coverage analysis
  -fcxx-exceptions        Enable C++ exceptions
  -fdata-sections         Place each data in its own section (ELF Only)
  -fdebug-prefix-map=<value>
                          remap file source paths in debug info
  -fdebug-types-section   Place debug types in their own section (ELF Only)
  -fdeclspec              Allow __declspec as a keyword
  -fdelayed-template-parsing
                          Parse templated function definitions at the end of the translation unit
  -fdiagnostics-parseable-fixits
                          Print fix-its in machine parseable form
  -fdiagnostics-print-source-range-info
                          Print source range spans in numeric form
  -fdiagnostics-show-note-include-stack
                          Display include stacks for diagnostic notes
  -fdiagnostics-show-option
                          Print option name with mappable diagnostics
  -fdiagnostics-show-template-tree
                          Print a template comparison tree for differing templates
  -fdollars-in-identifiers
                          Allow '$' in identifiers
  -fembed-bitcode-marker  Embed placeholder LLVM IR data as a marker
  -fembed-bitcode         Embed LLVM IR bitcode as data
  -femit-all-decls        Emit all declarations, even if unused
  -femulated-tls          Use emutls functions to access thread_local variables
  -fexceptions            Enable support for exception handling
  -ffast-math             Enable the *frontend*'s 'fast-math' mode. This has no effect on optimizations, but provides a preprocessor macro __FAST_MATH__ the same as GCC's -ffast-math flag
  -ffixed-r9              Reserve the r9 register (ARM only)
  -ffixed-x18             Reserve the x18 register (AArch64 only)
  -ffp-contract=<value>   Form fused FP ops (e.g. FMAs): fast (everywhere) | on (according to FP_CONTRACT pragma, default) | off (never fuse)
  -ffreestanding          Assert that the compilation takes place in a freestanding environment
  -ffunction-sections     Place each function in its own section (ELF Only)
  -fgnu-keywords          Allow GNU-extension keywords regardless of language standard
  -fgnu-runtime           Generate output compatible with the standard GNU Objective-C runtime
  -fgnu89-inline          Use the gnu89 inline semantics
  -fimplicit-module-maps  Implicitly search the file system for module map files.
  -finstrument-functions  Generate calls to instrument function entry and exit
  -fintegrated-as         Enable the integrated assembler
  -flto=<value>           Set LTO mode to either 'full' or 'thin'
  -flto                   Enable LTO in 'full' mode
  -fmath-errno            Require math functions to indicate errors by setting errno
  -fmax-type-align=<value>
                          Specify the maximum alignment to enforce on pointers lacking an explicit alignment
  -fmodule-file=<file>    Load this precompiled module file
  -fmodule-map-file=<file>
                          Load this module map file
  -fmodule-name= <name>   Specify the name of the module to build
  -fmodules-cache-path=<directory>
                          Specify the module cache path
  -fmodules-decluse       Require declaration of modules used within a module
  -fmodules-disable-diagnostic-validation
                          Disable validation of the diagnostic options when loading the module
  -fmodules-ignore-macro=<value>
                          Ignore the definition of the given macro when building and loading modules
  -fmodules-prune-after=<seconds>
                          Specify the interval (in seconds) after which a module file will be considered unused
  -fmodules-prune-interval=<seconds>
                          Specify the interval (in seconds) between attempts to prune the module cache
  -fmodules-search-all    Search even non-imported modules to resolve references
  -fmodules-strict-decluse
                          Like -fmodules-decluse but requires all headers to be in modules
  -fmodules-user-build-path <directory>
                          Specify the module user build path
  -fmodules-validate-once-per-build-session
                          Don't verify input files for the modules if the module has been successfully validated or loaded during this build session
  -fmodules-validate-system-headers
                          Validate the system headers that a module depends on when loading the module
  -fmodules               Enable the 'modules' language feature
  -fms-compatibility-version=<value>
                          Dot-separated value representing the Microsoft compiler version number to report in _MSC_VER (0 = don't define it (default))
  -fms-compatibility      Enable full Microsoft Visual C++ compatibility
  -fms-extensions         Accept some non-standard constructs supported by the Microsoft compiler
  -fmsc-version=<value>   Microsoft compiler version number to report in _MSC_VER (0 = don't define it (default))
  -fno-access-control     Disable C++ access control
  -fno-apinotes           Disable external API notes support
  -fno-assume-sane-operator-new
                          Don't assume that C++'s global operator new can't alias any pointer
  -fno-autolink           Disable generation of linker directives for automatic library linking
  -fno-builtin-<value>    Disable implicit builtin knowledge of a specific function
  -fno-builtin            Disable implicit builtin knowledge of functions
  -fno-common             Compile common globals like normal definitions
  -fno-constant-cfstrings Disable creation of CodeFoundation-type constant strings
  -fno-coverage-mapping   Disable code coverage analysis
  -fno-declspec           Disallow __declspec as a keyword
  -fno-diagnostics-fixit-info
                          Do not include fixit information in diagnostics
  -fno-dollars-in-identifiers
                          Disallow '$' in identifiers
  -fno-elide-constructors Disable C++ copy constructor elision
  -fno-elide-type         Do not elide types when printing diagnostics
  -fno-gnu-inline-asm     Disable GNU style inline asm
  -fno-integrated-as      Disable the integrated assembler
  -fno-lax-vector-conversions
                          Disallow implicit conversions between vectors with a different number of elements or different element types
  -fno-lto                Disable LTO mode (default)
  -fno-math-builtin       Disable implicit builtin knowledge of math functions
  -fno-merge-all-constants
                          Disallow merging of constants
  -fno-objc-infer-related-result-type
                          do not infer Objective-C related result type based on method family
  -fno-operator-names     Do not treat C++ operator name keywords as synonyms for operators
  -fno-profile-instr-generate
                          Disable generation of profile instrumentation.
  -fno-profile-instr-use  Disable using instrumentation data for profile-guided optimization
  -fno-reroll-loops       Turn off loop reroller
  -fno-rtti               Disable generation of rtti information
  -fno-sanitize-blacklist Don't use blacklist file for sanitizers
  -fno-sanitize-cfi-cross-dso
                          Disable control flow integrity (CFI) checks for cross-DSO calls.
  -fno-sanitize-coverage=<value>
                          Disable specified features of coverage instrumentation for Sanitizers
  -fno-sanitize-memory-track-origins
                          Disable origins tracking in MemorySanitizer
  -fno-sanitize-recover=<value>
                          Disable recovery for specified sanitizers
  -fno-sanitize-stats     Disable sanitizer statistics gathering.
  -fno-sanitize-trap=<value>
                          Disable trapping for specified sanitizers
  -fno-short-wchar        Force wchar_t to be an unsigned int
  -fno-show-column        Do not include column number on diagnostics
  -fno-show-source-location
                          Do not include source location information with diagnostics
  -fno-signed-char        Char is unsigned
  -fno-signed-zeros       Allow optimizations that ignore the sign of floating point zeros
  -fno-spell-checking     Disable spell-checking
  -fno-stack-protector    Disable the use of stack protectors
  -fno-standalone-debug   Limit debug information produced to reduce size of debug binary
  -fno-threadsafe-statics Do not emit code to make initialization of local statics thread safe
  -fno-trigraphs          Do not process trigraph sequences
  -fno-unroll-loops       Turn off loop unroller
  -fno-use-cxa-atexit     Don't use __cxa_atexit for calling destructors
  -fno-use-init-array     Don't use .init_array instead of .ctors
  -fobjc-arc-exceptions   Use EH-safe code when synthesizing retains and releases in -fobjc-arc
  -fobjc-arc              Synthesize retain and release calls for Objective-C pointers
  -fobjc-exceptions       Enable Objective-C exceptions
  -fobjc-gc-only          Use GC exclusively for Objective-C related memory management
  -fobjc-gc               Enable Objective-C garbage collection
  -fobjc-runtime=<value>  Specify the target Objective-C runtime kind and version
  -fobjc-weak             Enable ARC-style weak references in Objective-C
  -fpack-struct=<value>   Specify the default maximum struct packing alignment
  -fpascal-strings        Recognize and construct Pascal-style string literals
  -fpcc-struct-return     Override the default ABI to return all structs on the stack
  -fplugin=<dsopath>      Load the named plugin (dynamic shared object)
  -fprebuilt-module-path=<directory>
                          Specify the prebuilt module path
  -fprofile-generate=<directory>
                          Generate instrumented code to collect execution counts into <directory>/default.profraw (overridden by LLVM_PROFILE_FILE env var)
  -fprofile-instr-generate=<file>
                          Generate instrumented code to collect execution counts into <file> (overridden by LLVM_PROFILE_FILE env var)
  -fprofile-instr-generate
                          Generate instrumented code to collect execution counts into default.profraw file (overriden by '=' form of option or LLVM_PROFILE_FILE env var)
  -fprofile-instr-use=<value>
                          Use instrumentation data for profile-guided optimization
  -fprofile-sample-use=<value>
                          Enable sample-based profile guided optimizations
  -fprofile-use=<pathname>
                          Use instrumentation data for profile-guided optimization. If pathname is a directory, it reads from <pathname>/default.profdata. Otherwise, it reads from file <pathname>.
  -freciprocal-math       Allow division operations to be reassociated
  -freg-struct-return     Override the default ABI to return small structs in registers
  -freroll-loops          Turn on loop reroller
  -fsanitize-address-field-padding=<value>
                          Level of field padding for AddressSanitizer
  -fsanitize-blacklist=<value>
                          Path to blacklist file for sanitizers
  -fsanitize-cfi-cross-dso
                          Enable control flow integrity (CFI) checks for cross-DSO calls.
  -fsanitize-coverage=<value>
                          Specify the type of coverage instrumentation for Sanitizers
  -fsanitize-memory-track-origins=<value>
                          Enable origins tracking in MemorySanitizer
  -fsanitize-memory-track-origins
                          Enable origins tracking in MemorySanitizer
  -fsanitize-memory-use-after-dtor
                          Enable use-after-destroy detection in MemorySanitizer
  -fsanitize-recover=<value>
                          Enable recovery for specified sanitizers
  -fsanitize-stats        Enable sanitizer statistics gathering.
  -fsanitize-trap=<value> Enable trapping for specified sanitizers
  -fsanitize=<check>      Turn on runtime checks for various forms of undefined or suspicious behavior. See user manual for available checks
  -fshort-enums           Allocate to an enum type only as many bytes as it needs for the declared range of possible values
  -fshort-wchar           Force wchar_t to be a short unsigned int
  -fshow-overloads=<value>
                          Which overload candidates to show when overload resolution fails: best|all; defaults to all
  -fsized-deallocation    Enable C++14 sized global deallocation functions
  -fslp-vectorize-aggressive
                          Enable the BB vectorization passes
  -fslp-vectorize         Enable the superword-level parallelism vectorization passes
  -fstack-protector-all   Force the usage of stack protectors for all functions
  -fstack-protector-strong
                          Use a strong heuristic to apply stack protectors to functions
  -fstack-protector       Enable stack protectors for functions potentially vulnerable to stack smashing
  -fstandalone-debug      Emit full debug info for all types used by the program
  -fstrict-enums          Enable optimizations based on the strict definition of an enum's value range
  -fstrict-vtable-pointers
                          Enable optimizations based on the strict rules for overwriting polymorphic C++ objects
  -fthinlto-index=<value> Perform ThinLTO importing using provided function summary index
  -ftrap-function=<value> Issue call to specified function rather than a trap instruction
  -ftrapv-handler=<function name>
                          Specify the function to be called on overflow
  -ftrapv                 Trap on integer overflow
  -ftrigraphs             Process trigraph sequences
  -funique-section-names  Use unique names for text and data sections (ELF Only)
  -funroll-loops          Turn on loop unroller
  -fuse-init-array        Use .init_array instead of .ctors
  -fveclib=<value>        Use the given vector functions library
  -fvectorize             Enable the loop vectorization passes
  -fvisibility-inlines-hidden
                          Give inline C++ member functions default visibility by default
  -fvisibility-ms-compat  Give global types 'default' visibility and global functions and variables 'hidden' visibility by default
  -fvisibility=<value>    Set the default symbol visibility for all global declarations
  -fwrapv                 Treat signed integer overflow as two's complement
  -fwritable-strings      Store string literals as writable data
  -fzvector               Enable System z vector language extension
  -F <value>              Add directory to framework include search path
  --gcc-toolchain=<value> Use the gcc toolchain at the given directory
  -gcodeview              Generate CodeView debug information
  -gdwarf-2               Generate source-level debug information with dwarf version 2
  -gdwarf-3               Generate source-level debug information with dwarf version 3
  -gdwarf-4               Generate source-level debug information with dwarf version 4
  -gdwarf-5               Generate source-level debug information with dwarf version 5
  -gline-tables-only      Emit debug line number tables only
  -gmodules               Generate debug info with external references to clang modules or precompiled headers
  -g                      Generate source-level debug information
  -help                   Display available options
  -H                      Show header includes and nesting depth
  -iapinotes-modules <directory>
                          Add directory to the API notes search path referenced by module name
  -idirafter <value>      Add directory to AFTER include search path
  -iframework <value>     Add directory to SYSTEM framework search path
  -imacros <file>         Include macros from file before parsing
  -include-pch <file>     Include precompiled header file
  -include <file>         Include file before parsing
  -index-header-map       Make the next included directory (-I or -F) an indexer header map
  -index-ignore-system-symbols
                          Ignore symbols from system headers
  -index-record-codegen-name
                          Record the codegen name for symbols
  -index-store-path <value>
                          Enable indexing with the specified data store path
  -iprefix <dir>          Set the -iwithprefix/-iwithprefixbefore prefix
  -iquote <directory>     Add directory to QUOTE include search path
  -isysroot <dir>         Set the system root directory (usually /)
  -isystem <directory>    Add directory to SYSTEM include search path
  -ivfsoverlay <value>    Overlay the virtual filesystem described by file over the real file system
  -iwithprefixbefore <dir>
                          Set directory to include search path with prefix
  -iwithprefix <dir>      Set directory to SYSTEM include search path with prefix
  -iwithsysroot <directory>
                          Add directory to SYSTEM include search path, absolute paths are relative to -isysroot
  -I <value>              Add directory to include search path
  -mabicalls              Enable SVR4-style position-independent code (Mips only)
  -mcrc                   Allow use of CRC instructions (ARM only)
  -MD                     Write a depfile containing user and system headers
  -meabi <value>          Set EABI type, e.g. 4, 5 or gnu (default depends on triple)
  -mfix-cortex-a53-835769 Workaround Cortex-A53 erratum 835769 (AArch64 only)
  -mfp32                  Use 32-bit floating point registers (MIPS only)
  -mfp64                  Use 64-bit floating point registers (MIPS only)
  -MF <file>              Write depfile output from -MMD, -MD, -MM, or -M to <file>
  -mgeneral-regs-only     Generate code which only uses the general purpose registers (AArch64 only)
  -mglobal-merge          Enable merging of globals
  -MG                     Add missing headers to depfile
  -mhvx-double            Enable Hexagon Double Vector eXtensions
  -mhvx                   Enable Hexagon Vector eXtensions
  --migrate-xct           Apply modifications and produces temporary files to migrate to XCTest framework
  --migrate               Run the migrator
  -mincremental-linker-compatible
                          (integrated-as) Emit an object file which can be used with an incremental linker
  -mios-version-min=<value>
                          Set iOS deployment target
  -mllvm <value>          Additional arguments to forward to LLVM's option processing
  -mlong-calls            Generate an indirect jump to enable jumps further than 64M
  -mmacosx-version-min=<value>
                          Set Mac OS X deployment target
  -MMD                    Write a depfile containing user headers
  -mms-bitfields          Set the default structure layout to be compatible with the Microsoft compiler standard
  -mmsa                   Enable MSA ASE (MIPS only)
  -MM                     Like -MMD, but also implies -E and writes to stdout by default
  -mno-abicalls           Disable SVR4-style position-independent code (Mips only)
  -mno-fix-cortex-a53-835769
                          Don't workaround Cortex-A53 erratum 835769 (AArch64 only)
  -mno-global-merge       Disable merging of globals
  -mno-hvx-double         Disable Hexagon Double Vector eXtensions
  -mno-hvx                Disable Hexagon Vector eXtensions
  -mno-implicit-float     Don't generate implicit floating point instructions
  -mno-incremental-linker-compatible
                          (integrated-as) Emit an object file which cannot be used with an incremental linker
  -mno-long-calls         Restore the default behaviour of not generating long calls
  -mno-movt               Disallow use of movt/movw pairs (ARM only)
  -mno-ms-bitfields       Do not set the default structure layout to be compatible with the Microsoft compiler standard
  -mno-msa                Disable MSA ASE (MIPS only)
  -mno-restrict-it        Allow generation of deprecated IT blocks for ARMv8. It is off by default for ARMv8 Thumb mode
  -mno-unaligned-access   Force all memory accesses to be aligned (AArch32/AArch64 only)
  -mnocrc                 Disallow use of CRC instructions (ARM only)
  -module-dependency-dir <value>
                          Directory to dump module dependencies to
  -momit-leaf-frame-pointer
                          Omit frame pointer setup for leaf functions
  -MP                     Create phony target for each dependency (other than main file)
  -mqdsp6-compat          Enable hexagon-qdsp6 backward compatibility
  -MQ <value>             Specify name of main file output to quote in depfile
  -mrelax-all             (integrated-as) Relax all machine instructions
  -mrestrict-it           Disallow generation of deprecated IT blocks for ARMv8. It is on by default for ARMv8 Thumb mode.
  -mrtd                   Make StdCall calling convention the default
  -msoft-float            Use software floating point
  -mstack-alignment=<value>
                          Set the stack alignment
  -mstack-probe-size=<value>
                          Set the stack probe size
  -mstackrealign          Force realign the stack at entry to every function
  -mthread-model <value>  The thread model to use, e.g. posix, single (posix by default)
  -MT <value>             Specify name of main file output in depfile
  -munaligned-access      Allow memory accesses to be unaligned (AArch32/AArch64 only)
  -MV                     Use NMake/Jom format for the depfile
  -M                      Like -MD, but also implies -E and writes to stdout by default
  --no-system-header-prefix=<prefix>
                          Treat all #include paths starting with <prefix> as not including a system header.
  -nobuiltininc           Disable builtin #include directories
  -nostdinc++             Disable standard #include directories for the C++ standard library
  -ObjC++                 Treat source input files as Objective-C++ inputs
  -objcmt-atomic-property Make migration to 'atomic' properties
  -objcmt-migrate-all     Enable migration to modern ObjC
  -objcmt-migrate-annotation
                          Enable migration to property and method annotations
  -objcmt-migrate-designated-init
                          Enable migration to infer NS_DESIGNATED_INITIALIZER for initializer methods
  -objcmt-migrate-instancetype
                          Enable migration to infer instancetype for method result type
  -objcmt-migrate-literals
                          Enable migration to modern ObjC literals
  -objcmt-migrate-ns-macros
                          Enable migration to NS_ENUM/NS_OPTIONS macros
  -objcmt-migrate-property-dot-syntax
                          Enable migration of setter/getter messages to property-dot syntax
  -objcmt-migrate-property
                          Enable migration to modern ObjC property
  -objcmt-migrate-protocol-conformance
                          Enable migration to add protocol conformance on classes
  -objcmt-migrate-readonly-property
                          Enable migration to modern ObjC readonly property
  -objcmt-migrate-readwrite-property
                          Enable migration to modern ObjC readwrite property
  -objcmt-migrate-subscripting
                          Enable migration to modern ObjC subscripting
  -objcmt-ns-nonatomic-iosonly
                          Enable migration to use NS_NONATOMIC_IOSONLY macro for setting property's 'atomic' attribute
  -objcmt-returns-innerpointer-property
                          Enable migration to annotate property with NS_RETURNS_INNER_POINTER
  -objcmt-whitelist-dir-path=<value>
                          Only modify files with a filename contained in the provided directory path
  -ObjC                   Treat source input files as Objective-C inputs
  -omptargets=<value>     Specify comma-separated list of triples OpenMP offloading targets to be supported
  -o <file>               Write output to <file>
  -pg                     Enable mcount instrumentation
  -pipe                   Use pipes between commands, when possible
  -print-file-name=<file> Print the full library path of <file>
  -print-ivar-layout      Enable Objective-C Ivar layout bitmap print trace
  -print-libgcc-file-name Print the library path for "libgcc.a"
  -print-prog-name=<name> Print the full program path of <name>
  -print-search-dirs      Print the paths used for finding libraries and programs
  -pthread                Support POSIX threads in generated code
  -P                      Disable linemarker output in -E mode
  -Qunused-arguments      Don't emit warning for unused driver arguments
  -relocatable-pch        Whether to build a relocatable precompiled header
  -rewrite-legacy-objc    Rewrite Legacy Objective-C source to C++
  -rewrite-objc           Rewrite Objective-C source to C++
  -Rpass-analysis=<value> Report transformation analysis from optimization passes whose name matches the given POSIX regular expression
  -Rpass-missed=<value>   Report missed transformations by optimization passes whose name matches the given POSIX regular expression
  -Rpass=<value>          Report transformations performed by optimization passes whose name matches the given POSIX regular expression
  -R<remark>              Enable the specified remark
  -save-temps=<value>     Save intermediate compilation results.
  -save-temps             Save intermediate compilation results
  -serialize-diagnostics <value>
                          Serialize compiler diagnostics to a file
  -std=<value>            Language standard to compile for
  -stdlib=<value>         C++ standard library to use
  --system-header-prefix=<prefix>
                          Treat all #include paths starting with <prefix> as including a system header.
  -S                      Only run preprocess and compilation steps
  --target=<value>        Generate code for the given target
  -time                   Time individual commands
  -traditional-cpp        Enable some traditional CPP emulation
  -trigraphs              Process trigraph sequences
  -undef                  undef all system defines
  --verify-debug-info     Verify the binary representation of debug output
  -verify-pch             Load and verify that a pre-compiled header file is not stale
  -v                      Show commands to run and use verbose output
  -Wa,<arg>               Pass the comma separated arguments in <arg> to the assembler
  -Wl,<arg>               Pass the comma separated arguments in <arg> to the linker
  -working-directory <value>
                          Resolve file paths relative to the specified directory
  -Wp,<arg>               Pass the comma separated arguments in <arg> to the preprocessor
  -W<warning>             Enable the specified warning
  -w                      Suppress all warnings
  -Xanalyzer <arg>        Pass <arg> to the static analyzer
  -Xassembler <arg>       Pass <arg> to the assembler
  -Xclang <arg>           Pass <arg> to the clang compiler
  -Xcuda-fatbinary <arg>  Pass <arg> to fatbinary invocation
  -Xcuda-ptxas <arg>      Pass <arg> to the ptxas assembler
  -Xlinker <arg>          Pass <arg> to the linker
  -Xpreprocessor <arg>    Pass <arg> to the preprocessor
  -x <language>           Treat subsequent input files as having type <language>
  -z <arg>                Pass -z <arg> to the linker