Using the <prevent> tag to specify directories and emit options

You can use the <prevent> tag (nested under the <coverity> and <config> elements) to specify directories and certain build options in the configuration file instead of specifying them on the command line. Options that are specific to the build process reside under the <emit_options> tag. Table 1 describes some common configuration options and the equivalent command line option for each. If an option is specified both on the command line to a command and also in coverity_config.xml, the command line takes precedence.

Table 1. Options under the `<prevent>` tag in coverity_config.xml
Tag	Description	Overriding command line option
`<tmp_dir>`	The directory in which to place temporary files.	`tmpdir <dir>` `-t <dir>`
`<dir>`	The top-level directory that Coverity Analysis uses to determine the emit and output directories.	`dir <dir>`
`<parse_error_threshold>`	A child of the `<emit_options>` tag. The percentage of units that must successfully compile for the `cov-build` command to not return error code 8, and to not generate a warning. If less than this percentage compiles, the `cov-build` command returns a warning and the 8 error code. The default value is 95.	`parse-error-threshold <percentage>`
`<preprocess_first>`	A child of the `<emit_options>` tag. If specified, the `cov-build` command tries to preprocess each file with the native compiler before sending it to `cov-emit`. This tag does not take a value. Use if the build fails because of errors in `cov-emit` preprocessing.	`preprocess-first`
`<no_diff>`	A child of the `<emit_options>` tag. Specify to disable automatic diagnostic of compilation failures by trying to find differences between preprocessed files. This tag does not take a value.	`no-diff`
`<return_emit_failures>`	A child of the `<emit_options>` tag. If specified, `cov-build` returns with an error code if an emit failure occurs. The return value is a combination (a binary OR) of the following flags: 1 – The build returned an error code. 2 – The build terminated with an uncaught signal, such as a segmentation fault. 4 – No files were emitted. 8 – Some files failed to compile. By default, if less than 95% of the compilation units failed to compile, this error code is returned. To change this percentage, use the parse_error_threshold option. Note that `cov-build` always returns an error code if your build fails.	`return-emit-failures`
`<chase_symlinks>`	A child of the `<emit_options>` tag. If specified, `cov-build` and `cov-translate` follow symbolic links when compiling files. For example, if you compile a file called foo.c, which is a symbolic link to the file bar.c, and foo.c has an error in it, the error report lists bar.c if you used this flag, otherwise foo.c.	`chase-symlinks`
`<emit_cmd_line_id>`	A child of the `<emit_options>` tag. If specified, `cov-build` and option, see The 'cov-translate' command in place of the native compiler. `cov-translate` emit different files for the same file built with different command-line options. By default, these commands only emit a file the first time it is compiled. See Getting linkage information. This tag does not take a value.	`emit-cmd-line-id`

The tags described in Table 1 require a matching closing tag.

For example, see Figure 1.

Note: For cov-analyze, only the following XML tags are supported:

<tmp_dir>
<dir>

The following example modifies some common options.

Figure 1. XML configuration file example

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE coverity SYSTEM "coverity_config.dtd">
<coverity>

<!-- Version 1.0 -->
<cit_version>1</cit_version>
<config>

<prevent>
    <tmp_dir>/home/users/tests/temp</tmp_dir>
    <verbosity>2</verbosity>
    <emit_options>
        <emit_cmd_line_id/>
        <force_emit/>
        <return_emit_failures/>
        <chase_symlinks/>
    </emit_options>
</prevent>
</config>
</coverity>

Note: It is important to keep tags and their values on the same line. For example:

tmp_dir/home/user/tmp/data/tmp_dir

Using line breaks (as shown in the following example) can create pathnames with unintended characters (such as carriage returns) or cause other problems.

tmp_dir/home/user/tmp/ 
data/tmp_dir