### Run Example

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Run the executable(s) generated from a built example. This command is used after building an example.

```bash
make run
```

--------------------------------

### Specify Install Name for GPRinstall

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs a library project and records it under a custom install name 'myapp'.

```bash
gprinstall --install-name=myapp lib.gpr
```

--------------------------------

### Install LIBGPR Libraries

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Install the LIBGPR libraries. This make target handles the installation of the compiled GPR libraries.

```bash
make libgpr.install
```

--------------------------------

### Install All Sources

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs all source files. This is the default behavior and cannot be used with the -m option.

```bash
-a
```

--------------------------------

### Install in Developer Mode

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs all files necessary for development, including specs, ALI files, and the library itself. This is the default mode.

```bash
--mode=dev
```

--------------------------------

### Configuring a GPR Project for Library Building

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

This example demonstrates the essential attributes required to configure a GPR project file to build a library. It specifies the library name, object directory, and library installation directory.

```gpr
library project Logging is          --  "library" is optional
   for Library_Name use "logging";  --  will create "liblogging.a" on Unix
   for Object_Dir   use "obj";
   for Library_Dir  use "lib";      --  different from object_dir
end Logging;
```

--------------------------------

### Clean Example

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Clean up the build artifacts for an example. This command removes generated files after building and running an example.

```bash
make clean
```

--------------------------------

### Specify Installation Prefix

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Sets the root directory for the installation. If not provided, a default location based on the compiler is used.

```bash
--prefix={path}
```

--------------------------------

### GPRinstall with Prefix and Project Specification

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs a project with a specified root installation directory and explicitly names the project file.

```bash
gprinstall -r --prefix=/my/root/install -P prj2.gpr
```

--------------------------------

### Install Minimal Sources

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs only the interface sources. This option cannot be used with the -a option.

```bash
-m
```

--------------------------------

### Install in Usage Mode

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs only the library or executable, without generating project files, specs, or ALI files. This mode is for end-users.

```bash
--mode=usage
```

--------------------------------

### Examples of Attribute References

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Provides concrete examples of how to reference various attributes in GNAT project files. These examples demonstrate referencing project-level attributes, package attributes, and attributes with string literals.

```text
project'Object_Dir
Naming'Dot_Replacement
Imported_Project'Source_Dirs
Imported_Project.Naming'Casing
Builder'Default_Switches ("Ada")
```

--------------------------------

### Dry Run Installation

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Performs a dry run of the installation process, displaying the actions that would be taken without actually installing anything.

```bash
--dry-run
```

--------------------------------

### Split Function Example 2

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates splitting a string by a space separator. This example shows how multiple spaces are handled.

```gpr
Split ("-gnatf   -gnatv", " ")

=> ("-gnatf", "gnatv")
```

--------------------------------

### GPRbuild: Custom Configuration Project Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Shows how to specify a custom configuration project file using the --config switch.

```bash
$ gprbuild --config=my_standard.cgpr -P my_project.gpr
```

--------------------------------

### Bootstrap GPRbuild

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Use this command to bootstrap GPRbuild, specifying the installation prefix and paths to XML/Ada and gprconfig_kb sources. The script builds and installs GPRbuild to the specified location.

```bash
./bootstrap.sh --with-xmlada=../xmlada --with-kb=../gprconfig_kb --prefix=./bootstrap
```

--------------------------------

### GPRinstall for Usage Mode

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Installs only the executable files for a project named 'myapp', using the 'usage' mode.

```bash
gprinstall --install-name=myapp --mode=usage tools/tools.gpr
```

--------------------------------

### Specify Project File

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Specifies the project file to be used for the installation process.

```bash
-P{proj}
```

--------------------------------

### Specify Installation Name

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Defines the name recorded for the installation, which also serves as a suffix for include and library directories.

```bash
--install-name={name}
```

--------------------------------

### Basic GPRinstall Invocation

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Invokes GPRinstall to install a project. The main project file must be specified.

```bash
gprinstall prj1.gpr
```

--------------------------------

### String List Concatenation Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

A specific example demonstrating how to initialize a string list by concatenating an empty list with a file name.

```ada
List := () & File_Name; --  One string in this list
```

--------------------------------

### Apex File Naming Rules Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

An example package demonstrating various attributes to model Apex file naming rules, including casing, dot replacement, and language-specific suffixes for Ada.

```gpr
     package Naming is
       for Casing               use "lowercase";
       for Dot_Replacement      use ".";
       for Spec_Suffix ("Ada")  use ".1.ada";
       for Body_Suffix ("Ada")  use ".2.ada";
     end Naming;
```

--------------------------------

### Example Project Invocation

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Demonstrates how to invoke GPRbuild with a specific project file. This example shows a common error scenario where a specified source directory is invalid.

```bash
$ gprbuild -P my_project.gpr
ada_main.gpr:3:26: "src" is not a valid directory
gprbuild: "my_project.gpr" processing failed
```

--------------------------------

### Install GPRbuild

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Install GPRbuild after it has been built. This command copies the built executables and libraries to their designated locations.

```bash
make install
```

--------------------------------

### Specify Project Subdirectory

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Configures the subdirectory for installing project files. The default is 'share/gpr'.

```bash
--project-subdir={path}
```

--------------------------------

### Example Compiler Description with Environment Variable

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Retrieves the compiler version by reading the WIND_BASE environment variable.

```xml
<compiler_description>
<name>GCC-WRS</name>
<executable prefix="1">cc(arm|pentium)</executable>
<version>
<getenv name="WIND_BASE" />
</version>
</compile_description>
```

--------------------------------

### Create Missing Directories

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Ensures that all necessary directories in the installation path are created if they do not already exist.

```bash
-p
```

--------------------------------

### Basic Project File Structure with Empty Packages

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

An example of a project file defining basic source and output directories, main unit, and empty packages for build tools. These packages can be populated with specific attributes.

```gpr
project Build is
   for Source_Dirs use ("common");
   for Object_Dir use "obj";
   for Exec_Dir use ".";
   for Main use ("proc.adb");

   package Builder is  --<<<  for gprbuild
   end Builder;

   package Compiler is --<<<  for the compiler
   end Compiler;

   package Binder is   --<<<  for the binder
   end Binder;

   package Linker is   --<<<  for the linker
   end Linker;
end Build;
```

--------------------------------

### Specify Build Variables for Installation

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Use --build-var to specify project-specific and generic build variables for selecting installations. If the first variable is not found, subsequent ones are checked.

```bash
$ gprinstall -Pproject1 \
  --build-var=PROJECT1_BUILD,LIBRARY_TYPE

$ gprinstall -Pproject2 \
  --build-var=PROJECT2_BUILD,LIBRARY_TYPE
```

--------------------------------

### GPRclean Invocation Examples

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Basic examples of how to invoke the GPRclean tool to remove build artifacts. Specify the project file to clean.

```bash
gprclean -r prj1.gpr
```

```bash
gprclean -c -P prj2.gpr
```

--------------------------------

### Specify Sources Subdirectory

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Configures the subdirectory for installing source files. The default is 'include/<project_name>[.<build-name>]'.

```bash
--sources-subdir={path}
```

--------------------------------

### Example GPRbuild Configuration Chunks

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Illustrates how to define GPRbuild configuration chunks that can be merged. Shows how to append values to existing attributes to avoid conflicts.

```gpr
chunk1:
   package Language_Processing is
     for Attr1 use ("foo");
   end Language_Processing;
chunk2:
   package Language_Processing is
     for Attr1 use ("bar");
   end Language_Processing;
```

```gpr
package Language_Processing is
  for Attr1 use ("foo", "bar");
end Language_Processing;
```

```gpr
chunk1:
  package Language_Processing is
    for Attr1 use Language_Processing'Attr1 & ("foo");
  end Language_Processing;
chunk2:
  package Language_Processing is
    for Attr1 use Language_Processing'Attr1 & ("bar");
end Language_Processing;
```

--------------------------------

### Specify Executables Subdirectory

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Configures the subdirectory for installing executables. The default is 'bin'.

```bash
---exec-subdir={path}
```

--------------------------------

### Specify Library Subdirectory

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Configures the subdirectory for installing library and object files. The default is 'lib/<project_name>[.<build-name>]'.

```bash
--lib-subdir={path}
```

--------------------------------

### Host Filter Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Example of a <hosts> filter to activate a chunk only on Intel Linux machines. The 'name' attribute is a regexp matched against the current architecture.

```gpr
<hosts>
  <host name="i.86-.*-linux(-gnu)?" />
</hosts>
```

--------------------------------

### GPRbuild: Missing Project File Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Demonstrates the error message when GPRbuild is invoked without a project file specified after the -P switch.

```bash
$ gprbuild -P
gprbuild: project file name missing after -P
```

--------------------------------

### Example Compiler Description with Languages

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Defines a simple compiler description with a hardcoded list of supported languages.

```xml
<compiler_description>
<name>GNAT</name>
<executable>gnatmake</executable>
<languages>Ada</languages>
</compiler_description>
```

--------------------------------

### Naming Convention Example for C and C++

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates how to specify different body and spec suffixes for C and C++ languages. Attributes are case-insensitive.

```gpr
package Naming is
  for Body_Suffix ("c") use ".c";
  for Body_Suffix ("c++") use ".C";
  for Spec_Suffix ("c") use ".h";
  for Spec_Suffix ("c++") use ".H";
end Naming;
```

--------------------------------

### Split Function Example 1

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates splitting a string by a comma separator. The Split function takes the string to split and the separator as arguments.

```gpr
Split ("-gnatf,-gnatv", ",")

=> ("-gnatf", "gnatv")
```

--------------------------------

### Force Overwrite Existing Files

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Forces gprinstall to overwrite existing files during the installation process.

```bash
-f
```

--------------------------------

### GPRbuild Command Execution Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

This output shows a typical GPRbuild command execution for a project named 'pc_main'. It details the compilation steps for various source files (Ada and C) and the final linking stage.

```sh
$ gprbuild -Pc_main
gcc -c -pedantic -g main.c
gcc -c -gnaty proc.adb
gcc -c -gnaty pack.adb
gcc -c -pedantic utils.c
gprbind main.bexch
...
gcc main.o -o main
```

--------------------------------

### Example: Querying GCC Machine Type

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Executes an external command 'gcc -dumpmachine' to determine the target processor.

```xml
<version>
<external>gcc -dumpmachine</external>
</version>
```

--------------------------------

### GPRbuild Case Construction Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates a case construction in a GPRbuild project file using a typed string variable to conditionally set compiler switches.

```gpr
project MyProj is
   type OS_Type is ("GNU/Linux", "Unix", "Windows", "VMS");
   OS : OS_Type := external ("OS", "GNU/Linux");

   package Compiler is
     case OS is
       when "GNU/Linux" | "Unix" =>
         for Switches ("Ada")
             use ("-gnath");
       when "Windows" =>
         for Switches ("Ada")
             use ("-gnatP");
       when others =>
         null;
     end case;
   end Compiler;
end MyProj;
```

--------------------------------

### Example: Extracting GCC Version

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Executes 'gcc -v' and uses a grep filter to extract the version number from the output.

```xml
<version>
<external>gcc -v</external>
<grep regexp="^gcc version (\S+)" group="1" />
</version>
```

--------------------------------

### Example gprname usage with multiple directories and patterns

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Demonstrates using gprname with multiple source directories (-d), a directory file (-D), and various naming and exclusion patterns.

```sh
$ gprname -P/home/me/proj.gpr -x "*_nt_body.ada"
-dsources -dsources/plus -Dcommon_dirs.txt "body_*" "spec_*"
```

--------------------------------

### GPRbuild Project Extension Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Defines a project 'Work' that extends a base build project and specifies source files.

```gpr
project Work extends "../bld/build.gpr" is
   for Source_Files use ("pack.ads");
   --  New spec of Pkg does not need a completion
   for Excluded_Source_Files use ("pack.adb");
end Work;

```

--------------------------------

### GPRbuild Verbose Output Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates the verbose output of GPRbuild using the -v option, which includes more detailed compilation, post-compilation, and link commands.

```sh
$ gprbuild -Pbuild
gcc -c proc.adb
gcc -c pack.adb
gcc -c utils.c
gprbind proc
...
gcc proc.o -o proc
```

--------------------------------

### GPRbuild: Illegal Option Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Illustrates the error message when GPRbuild encounters an illegal command-line option.

```bash
$ gprbuild -P c_main.gpr -WW
gprbuild: illegal option "-WW"
```

--------------------------------

### Specify Output Configuration File

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Use the -o switch to specify the name of the configuration file to be generated. If omitted, a default file is created in the GPRbuild installation directory.

```bash
-o {file}
```

--------------------------------

### Cyclic Dependency Example with Limited With

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates how 'limited with' allows cyclic dependencies between projects, but restricts the use of imported project attributes in the importing project.

```gpr
with "b.gpr";
with "c.gpr";
project A is
    for Exec_Dir use B'Exec_Dir; -- OK
end A;

limited with "a.gpr";   --  Cyclic dependency: A -> B -> A
project B is
   for Exec_Dir use A'Exec_Dir; -- not OK
end B;

with "d.gpr";
project C is
end C;

limited with "a.gpr";  --  Cyclic dependency: A -> C -> D -> A
project D is
   for Exec_Dir use A'Exec_Dir; -- not OK
end D;
```

--------------------------------

### Configure Source Directories and Ignore Subdirectories

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Use Source_Dirs to include all files in the specified directory and its subdirectories. Use Ignore_Source_Sub_Dirs to exclude specific subdirectories like .svn or those starting with '@'.

```gpr
for Source_Dirs use ("./**");
for Ignore_Source_Sub_Dirs use (".svn", "@*");
```

--------------------------------

### GPRslave Hash String Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Use the --hash option with gprslave to ensure the GPRbuild hash value matches, aborting the connection if it does not.

```bash
$ gprslave --hash=$(echo $ADA_PROJECT_PATH | shasum)
```

--------------------------------

### Filtering Compiler Languages

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

This example demonstrates filtering the output of a compiler command to select specific languages. It uses the `<filter>` node to keep only specified words from the compiler's output.

```xml
<languages>
<external regexp="languages=(\S+)" group="1">gcc -v</external>
<filter>c,c++,fortran</filter>
</languages>
```

--------------------------------

### Uninstall Project by Install Name

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Uninstalls a project previously installed under the name 'prj1'.

```bash
gprinstall --uninstall prj1
```

--------------------------------

### Uninstall Multiple Projects by Common Install Name

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Uninstalls multiple projects that were previously installed under the common name 'myapp'.

```bash
gprinstall --uninstall myapp
```

--------------------------------

### Building Projects with GPRbuild

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Illustrates the command-line usage of GPRbuild for building individual projects and aggregate projects.

```sh
gprbuild -PA.gpr
```

```sh
gprbuild -PAgg.gpr
```

```sh
gprbuild -PA.gpr
gprbuild -PB.gpr
```

--------------------------------

### Compiler Filter Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Example of a <compiler> filter to match GNAT compilers in the 5.x family. Attributes are matched as regular expressions.

```gpr
<compiler name="GNAT" version="5.\d+" />
```

--------------------------------

### gprname Naming Pattern Examples

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Examples of naming patterns that gprname can use to identify Ada source files. These patterns are similar to shell wildcards.

```sh
"*. [12].ada"
```

```sh
"*.ad[sb]*"
```

```sh
"body_*"
```

```sh
"spec_*"
```

--------------------------------

### Target Filter Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Example of a <targets> filter to activate a chunk only when the code is targeted for Linux. The 'name' attribute is a regexp matched against the target architecture.

```gpr
<targets>
  <target name="i.86-.*-linux(-gnu)?" />
</targets>
```

--------------------------------

### Alternative GPRbuild Commands

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates equivalent GPRbuild commands for specifying the project, allowing flexibility in how the project file is referenced.

```sh
gprbuild -P build
gprbuild -P build.gpr
gprbuild -P ./build.gpr
```

--------------------------------

### Disable Library Linking

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Disables the copying of shared libraries into the installation directory.

```bash
--no-lib-link
```

--------------------------------

### Add Knowledge Base Directory

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Use the --db switch to indicate an additional directory to be parsed for GPRconfig's knowledge base, useful for local XML description files. The --db- switch prevents reading the default knowledge base.

```bash
--db {directory}
```

```bash
--db-
```

--------------------------------

### Empty Package Declaration

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

An example of a minimal, empty package declaration within a GNAT project file.

```gpr
project Simple is
  package Builder is
  end Builder;
end Simple;
```

--------------------------------

### Building Library and Main Projects

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Commands to build a library project and a dependent main project to ensure all sources are up-to-date. The first command builds the library, and the second builds the project that uses the library.

```sh
gprbuild -Plogging.gpr
gprbuild -Pbuild.gpr
```

--------------------------------

### Sharing Compiler and Binder Switches Between Projects

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Shows how to share compiler and binder switch configurations between projects using 'renames' and attribute referencing to avoid duplication.

```gpr
project Logging is
   package Compiler is
      for Switches ("Ada")
          use ("-O2");
   end Compiler;
   package Binder is
      for Switches ("Ada")
          use ("-E");
   end Binder;
end Logging;

with "logging.gpr";
project Build is
   package Compiler renames Logging.Compiler;
   package Binder is
      for Switches ("Ada") use Logging.Binder'Switches ("Ada");
   end Binder;
end Build;
```

--------------------------------

### Enable Library Auto Initialization Support

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Specifies whether library auto initialization is supported. Defaults to 'false'.

```gpr
for Library_Auto_Init_Supported use "true";
```

--------------------------------

### Configure Dependency Driver for C

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Specifies the command and options to create a dependency file for C sources. The full path name of the source is appended to the last string of the string list value.

```gpr
for Dependency_Driver ("C") use ("gcc", "-E", "-Wp,-M", "");
```

--------------------------------

### Default Language Configuration

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Specifies the default language for project sources when the 'Languages' attribute is not declared. Example sets the default to 'ada'.

```gpr
for Default_Language use "ada";
```

--------------------------------

### Passing Compiler Arguments with -cargs

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Example of using the -cargs separator on the GPRbuild command line to pass options to all compilers for all languages.

```bash
-cargs opts
```

--------------------------------

### GPRbuild Indexed Attribute Inheritance Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Demonstrates how indexed attributes can be inherited or overridden, including copying attribute values from another package.

```gpr
--  indexed attributes copy (from package Builder in project Default)
--  The package name must always be specified, even if it is the current
--  package.
for Default_Switches use Default.Builder'Default_Switches;
```

--------------------------------

### Configure Compiler with Path and Name

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Use the --config switch with optional arguments for path and compiler name to specify a particular compiler executable or distinguish between multiple compilers.

```bash
gprconfig --config Ada,,,/usr/bin
```

```bash
gprconfig --config C,,,/usr/bin,GCC
```

```bash
gprconfig --config C,,,/usr/bin,gcc
```

--------------------------------

### Specify Partial Linker Command

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Sets the executable and options for the partial linker. If not specified, partial linking is not performed.

```gpr
for Library_Partial_Linker use ("gcc", "-nostdlib", "-Wl,-r", "-o");
```

--------------------------------

### Build Main Executables

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Build the main GPRbuild executables. This command assumes static linking with XML/Ada by default.

```bash
make all
```

--------------------------------

### Specify Mapping Spec Suffix

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Defines the suffix for mapping files for unit specs in languages that support mapping files. Example uses '%s'.

```gpr
for Mapping_Spec_Suffix ("Ada") use "%s";
```

--------------------------------

### Show All Available Targets

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Use the --show-target switch to display all compilers found on the PATH that match the specified target.

```bash
gprconfig --show-targets
```

--------------------------------

### Specify Mapping Body Suffix

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Defines the suffix for mapping files for unit bodies in languages that support mapping files. Example uses '%b'.

```gpr
for Mapping_Spec_Suffix ("Ada") use "%b";
```

--------------------------------

### GPRbuild Indexed Attribute Declarations

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Shows examples of declaring indexed attributes in GPRbuild, such as specifying the main body file or compiler switches for specific source files.

```gpr
--  indexed attributes
for Body ("main") use "Main.ada";
for Switches ("main.ada")
    use ("-v", "-gnatv");
for Switches ("main.ada") use Builder'Switches ("main.ada") & "-g";
```

--------------------------------

### Launch GPRbuild in Distributed Mode (GPR_SLAVES_FILE)

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Configure distributed compilation by providing a file path to the GPR_SLAVES_FILE environment variable, where each line lists a build slave.

```bash
$ export GPR_SLAVES_FILE=$HOME/slave-list.txt
$ gprbuild --distributed prj.gpr
```

--------------------------------

### Typed String Declaration Example

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/gnat_project_manager.rst

Declares a new string type 'OS' with a restricted set of literal values. This type can only hold one of the specified string values.

```ada
type OS is ("GNU/Linux", "Unix", "Windows", "VMS");
```

--------------------------------

### Correct Variable Substitution in Configuration for Ada

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Demonstrates the correct syntax for variable substitution within a `<configuration>` block when specifying the driver for the Ada language. It shows how to use language-specific variables.

```gpr
for Driver ("Ada") use "${PATH(ada)}gcc";   --  Correct
```

--------------------------------

### GPRconfig XML Configuration with Config Chunk

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Example of an XML structure for GPRconfig, showing a `<configuration>` node containing a `<config>` child element with a GPRbuild package definition.

```xml
<configuration>
  ...
  <config>
  package Language_Processing is
     for Attr1 use Language_Processing'Attr1 & ("foo");
  end Language_Processing;
  </config>
</configuration>
```

--------------------------------

### Build with Dynamic XML/Ada Linking

Source: https://github.com/adacore/gprbuild/blob/master/README.md

Build GPRbuild executables with dynamic linking to XML/Ada. This is an alternative to the default static linking.

```bash
make LIBRARY_TYPE=relocatable all
```

--------------------------------

### Configure Objects Path for Ada

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Specifies an environment variable for the Ada compiler to get the object search path. The value of the environment variable is the object search path.

```gpr
for Objects_Path ("Ada") use "ADA_OBJECTS_PATH";
```

--------------------------------

### Display Path Information

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/building_with_gprbuild.rst

Outputs the configuration project file search path and the user path. This helps in understanding where GPRbuild looks for project files.

```bash
--display-paths
```

--------------------------------

### Configure Include Path for C and Ada

Source: https://github.com/adacore/gprbuild/blob/master/doc/gprbuild_ug/companion_tools.rst

Specifies environment variables used by the compiler to get the source search path. The value of the environment variable is the source search path.

```gpr
for Include_Path ("C")   use "CPATH";
for Include_Path ("Ada") use "ADA_INCLUDE_PATH";
```