# NSPR build instructions

## Prerequisites

On Windows, the NSPR build system needs GNU make and a Unix command-line
utility suite such as MKS Toolkit, Cygwin, and MSYS. The easiest way to
get these tools is to install the
`MozillaBuild` package.

## Introduction

The top level of the NSPR source tree is the `mozilla/nsprpub`
directory. Although `nsprpub` is a subdirectory under `mozilla`,
NSPR is independent of the Mozilla client source tree.

Building NSPR consists of three steps:

1. run the configure script. You may override the compilers (the CC
   environment variable) or specify options.
2. build the libraries
3. build the test programs

For example,

```
# check out the source tree from Mercurial
hg clone https://hg.mozilla.org/projects/nspr
# create a build directory
mkdir target.debug
cd target.debug
# run the configure script
../nspr/configure [optional configure options]
# build the libraries
gmake
# build the test programs
cd pr/tests
gmake
```

On Mac OS X, use `make`, which is GNU `make`.

(configure-options)=

## Configure options

Although NSPR uses autoconf, its configure script has two default values
that are different from most open source projects.

1. If the OS vendor provides a compiler (for example, Sun and HP), NSPR
   uses that compiler instead of GCC by default.
2. NSPR build generates a debug build by default.

(disable-debug-enable-optimize)=

### --disable-debug --enable-optimize

Specify these two options to generate an optimized (release) build.

These two options can actually be used independently, but it's not
recommended.

### --enable-64bit

On a dual 32-bit/64-bit platform, NSPR build generates a 32-bit build by
default. To generate a 64-bit build, specify the `--enable-64bit`
configure option.

(targetx86-64-pc-mingw32)=

### --target=x86_64-pc-mingw32

For 64-bit builds on Windows, when using the mozbuild environment.

(enable-win32-target-3dwin95)=

### --enable-win32-target=WIN95

This option is only used on Windows. NSPR build generates a "WINNT"
configuration by default on Windows for historical reasons. We recommend
most applications use the "WIN95" configuration. The "WIN95"
configuration supports all versions of Windows. The "WIN95" name is
historical; it should have been named "WIN32".

To generate a "WIN95" configuration, specify the
`--enable-win32-target=WIN95` configure option.

(enable-debug-rtl)=

### --enable-debug-rtl

This option is only used on Windows. NSPR debug build uses the release C
run-time library by default. To generate a debug build that uses the
debug C run-time library, specify the `--enable-debug-rtl` configure
option.

(makefile-targets)=

## Makefile targets

- all (default)
- clean
- realclean
- distclean
- install
- release

(running-the-test-programs)=

## Running the test programs

The tests were built above, in the `pr/tests` directory.

On Mac OS X, they can be executed with the following:

```{code}
/bin/sh:

$ cd pr/tests
$ DYLD_LIBRARY_PATH=../../dist/lib ./accept
PASS
$
$ # to run all the NSPR tests...
$
$ DYLD_LIBRARY_PATH=../../dist/lib ../../../nspr/pr/tests/runtests.sh ../..
```