Invoking the Compiler - Oracle® Developer Studio 12.6: C++ User's Guide

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2.2 Invoking the Compiler

The remainder of this chapter discusses the conventions used by the CC command, compiler source line directives, and other issues concerning the use of the compiler.

2.2.1 Command Syntax

The general syntax of a compiler command line is as follows:

CC [options] [source-files] [object-files] [libraries]

An option is an option keyword prefixed by either a dash (–) or a plus sign (+). Some options take arguments.

In general, the processing of the compiler options is from left to right, allowing selective overriding of macro options (options that include other options). In most cases, if you specify the same option more than once, the rightmost assignment overrides and there is no accumulation. Note the following exceptions:

All linker options and the -features, –I -l,– L, -library, –pti, –R, -staticlib, -U, -verbose, -xdumpmacros, and -xprefetch options accumulate, they do not override.
All –U options are processed after all –D options.

Source files, object files, and libraries are compiled and linked in the order in which they appear on the command line.

In the following example, CC is used to compile two source files (growth.C and fft.C) to produce an executable file named growth with runtime debugging enabled:

example% CC -g -o growth growth.C fft.C

2.2.2 File Name Conventions

The suffix attached to a file name appearing on the command line determines how the compiler processes the file. A file name with a suffix other than those listed in the following table, or without a suffix, is passed to the linker.

Table 1 File Name Suffixes Recognized by the C++ Compiler

Suffix	Language	Action
`.c`	C++	Compile as C++ source files, put object files in current directory; default name of object file is that of the source but with an `.o` suffix.
`.C`	C++	Same action as `.c` suffix.
`.cc`	C++	Same action as `.c` suffix.
`.cpp`	C++	Same action as `.c` suffix.
`.cxx`	C++	Same action as `.c` suffix.
`.c++`	C++	Same action as `.c` suffix.
`.i`	C++	Preprocessor output file treated as C++ source file. Same action as `.c` suffix.
`.s`	Assembler	Assemble source files using the assembler.
`.S`	Assembler	Assemble source files using both the C language preprocessor and the assembler.
`.il`	Inline expansion	Process assembly inline-template files for inline expansion. The compiler will use templates to expand inline calls to selected routines. (Inline-template files are special assembler files. See the `inline`(1) man page.)
`.o`	Object files	Pass object files through to the linker.
`.a`	Static (archive) library	Pass object library names to the linker.
`.so` .`so`.n	Dynamic (shared) library	Pass names of shared objects to the linker.

2.2.3 Using Multiple Source Files

The C++ compiler accepts multiple source files on the command line. A single source file compiled by the compiler, together with any files that it directly or indirectly includes, is referred to as a compilation unit . C++ treats each source as a separate compilation unit.