Provided by: clang_2.7-0ubuntu1_i386 bug


       clang - the Clang C and Objective-C compiler


         -Wwarnings... -pedantic
         -Idir... -Ldir...
         -o output-file


       clang is a C and Objective-C compiler which encompasses preprocessing,
       parsing, optimization, code generation, assembly, and linking.
       important to understand the stages of compilation, to understand how to
       invoke it.  These stages are:

           The clang executable is actually a small driver which controls the
           overall execution of other tools such as the compiler, assembler
           but you transparently use it to run the other tools.

           This stage handles tokenization of the input source file, macro
           expansion, #include expansion and handling of other preprocessor
           (for C) or ".mi" (for Objective-C) file.

       Parsing and Semantic Analysis
           This stage parses the input file, translating preprocessor tokens
           semantic analysis to compute types for expressions as well and
           determine whether the code is well formed. This stage is
           responsible for generating most of the compiler warnings as well as
           Tree" (AST).

       Code Generation and Optimization
           This stage translates an AST into low-level intermediate code
           (known as "LLVM IR") and ultimately to machine code (depending on
           the optimization level).  This phase is responsible for optimizing
           the generated code and handling target-specfic code generation.
           "assembly" file.

           This stage runs the target assembler to translate the output of the

           This stage runs the target linker to merge multiple object files

       The Clang compiler supports a large number of options to control each
       supports other tools:

       Clang Static Analyzer

       find bugs though code analysis.  This tool uses many parts of Clang and
       is built into the same driver.


   Stage Selection Options
       -E  Run the preprocessor stage.

           Run the preprocessor, parser and type checking stages.

           stages and target-specific code generation, producing an assembly

           object file.

       no stage selection option
           If no stage selection option is specified, all stages above are
           executable or shared library.

           Run the Clang Static Analyzer.

   Language Selection and Mode Options
       -x language
           Treat subsequent input files as having type language.

           Specify the language standard to compile for.

           Same as -std=c89.

           Treat source input files as Objective-C++ inputs.

           Treat source input files as Objective-C inputs.

           Enable trigraphs.

           hosted, environment.

           Disable special handling and optimizations of builtin functions
           like strlen and malloc.

           Indicate that math functions should be treated as updating errno.


           Enable support for Microsoft extensions.

           Make all string literals default to writable.  This disables
           uniquing of strings and other optimizations.

           Allow loose type checking rules for implicit vector conversions.

           Enable the "Blocks" language feature.

           which only works when Objective-C Garbage Collection is enabled.


   Target Selection Options
       Clang fully supports cross compilation as an inherent part of its
       native target.

       -arch architecture
           Specify the architecture to build for.

           by your application.

           When building for iPhone OS, specify the minimum version supported
           by your application.

           Specify that Clang should generate code for a specific processor
           the compiler is allowed to generate instructions that are valid on

   Code Generation Options
       -O0 -O1 -O2 -Os -O3 -O4
           Specify which optimization level to use.  -O0 means "no
           optimization": this level compiles the fastest and generates the
           most debuggable code.  -O2 is a moderate level of optimization
           which enables most optimizations.  -Os is like -O2 with extra
           optimizations to reduce code size.  -O3 is like -O2, except that it
           enables optimizations that take longer to perform or that may
           generate larger code (in an attempt to make the program run
           faster).  On supported platforms, -O4 enables link-time
           optimization; object files are stored in the LLVM bitcode file
           format and whole program optimization is done at link time. -O1 is
           somewhere between -O0 and -O2.

       -g  Generate debug information.  Note that Clang debug information
           information is currently available.

           Enable generation of unwind information, this allows exceptions to
           be thrown through Clang compiled stack frames.  This is on by
           default in x86-64.

           Generate code to catch integer overflow errors.  Signed integer
           to detect this and abort when it happens.

           This flag sets the default visibility level.

           This flag specifies that variables without initializers get common
           linkage.  It can be disabled with -fno-common.

       -flto -emit-llvm
           Generate output files in LLVM formats, suitable for link time
           optimization. When used with -S this generates LLVM intermediate
           language assembly files, otherwise this generates LLVM bitcode
           the stage selection options).

   Driver Options
           Print the commands to run for this compilation.

           Display available options.

           Don't emit warning for unused driver arguments.

           Pass the comma separated arguments in args to the assembler.

           Pass the comma separated arguments in args to the linker.

           Pass the comma separated arguments in args to the preprocessor.

       -Xanalyzer arg
           Pass arg to the static analyzer.

       -Xassembler arg
           Pass arg to the assembler.

       -Xclang arg
           Pass arg to the clang compiler.

       -Xlinker arg
           Pass arg to the linker.

       -Xpreprocessor arg
           Pass arg to the preprocessor.

       -o file
           Write output to file.

           Print the full library path of file.

           Print the library path for "libgcc.a".

           Print the full program path of name.

           Print the paths used for finding libraries and programs.

           Save intermediate compilation results.

           Time individual commands.

           Print timing summary of each stage of compilation.

       -v  Show commands to run and use verbose output.

   Diagnostics Options
       -fdiagnostics-fixit-info -fdiagnostics-print-source-range-info
       -fprint-source-range-info -fdiagnostics-show-option -fmessage-length
           These options control how Clang prints out information about
           diagnostics (errors and warnings).  Please see the Clang User's
           Manual for more information.

   Preprocessor Options
           Adds an implicit #define into the predefines buffer which is read
           before the source file is preprocessed.

           Adds an implicit #undef into the predefines buffer which is read
           before the source file is preprocessed.

       -include filename
           Adds an implicit #include into the predefines buffer which is read
           before the source file is preprocessed.

           Add the specified directory to the search path for include files.

           Add the specified directory to the search path for framework
           include files.

           Do not search the standard system directories for include files.

           Do not search clang's builtin directory for include files.


           These environment variables are checked, in order, for the location
           to write temporary files used during the compilation process.

           If this environment variable is present, it is treated as a
           delimited list of paths to be added to the default system include
           path list. The delimiter is the platform dependent delimitor, as
           used in the PATH environment variable.

           Empty components in the environment variable are ignored.

           These environment variables specify additional paths, as for CPATH,
           which are only used when processing the appropriate language.

           target is read from this environment variable.  This option only
           affects darwin targets.


       Clang currently does not have C++ support, and this manual page is
       incomplete.  To report bugs, please visit <>.


        as(1), ld(1)


       Maintained by the Clang / LLVM Team (<>).