For backwards compatibility, you can still invoke the ARM compiler using one of the tool names supported in earlier compilation tools. The startup configuration associated with each of the older tool names is shown in Table 2.1.

Table 2.2 shows how the compiler start-up configuration is adjusted by the filename extension you specify.

When you compile multiple files with a single command, all files must of the same type (either C or C++). The compiler cannot switch the language based on the file extension. The following example produces an error, because the compiler attempts to compile using the source language of test1.c:

armcc -c test1.c test2.cpp
Error: C3472E: No source language specified (--cpp or --c90) and sourcefile extensions conflict

If you specify files with conflicting file extensions you can force the compiler to compile either for C or for C++, regardless of file extension. For example:

armcc -c --cpp test1.c test2.cpp

See Setting the source language for details.

Support for processing PreCompiled Header (PCH) files is not available when you specify multiple source files in a single compilation. If you request PCH processing and specify more than one primary source file, the compiler issues an error message, and aborts the compilation. See Precompiled header files for details.

You can override the adjustments that the ARM compiler makes based on the filename extension (see Table 2.2) or the tool name you used to invoke the compiler (see Table 2.1). To do this, use the appropriate command-line option as shown in Table 2.3. See Pragmas controlling code generation for information on using pragmas to set source language.

For example, if you submit the following command:

tcpp foo.acpp --c90

The compiler makes determinations as shown in Table 2.4.

The configuration that results from these considerations is shown in the Result row at the bottom of the table.

To summarize:

See Setting the source language and Targeting the instruction set for details on these options.