Build - jasper-zanjani/dotfiles GitHub Wiki

• autoconf
• cc
• g++
• gdb
• make
• xgettext

Other related programs are usually invoked automatically by tools in the autoconf suite: autoreconf, autoscan, and autoupdate

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-g will run gdb during compilation.

gdb allows you to debug an application from the terminal with interactive commands:

• s step into
• n step over (execute the currently visualized line of code)
• p print value of a variable (i.e. p x will display the current value of variable x)

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A common formula when installing software from source is the following sequence of commands

./configure
make
make install

Given there are 3 example files (main.cpp, message.cpp, and message.h) in a directory, it produces an executable file named a.out

g++ main.cpp message.cpp

Install an alternate version of a program like Python

cd /opt
wget https://www.python.org/ftp/python/3.8.0/Python-3.8.0.tgz
tar xzf Python-3.8.0.tgz
cd Python-3.8.0
./configure --enable-optimizations
make altinstall

Makefiles are sensitive to whitespace, so indentation is significant. The format follows the pattern:

{target}: {dependencies}
  {action}

where {target} is the filename produced by the operation {action}, each of which are shell commands.

In this example, hw.o is produced from hw.cpp first because it is a dependency of the executable hw. Notably, Makefiles appear to require hard tabs.

CC = g++
all: hw
hw: hw.o
  ${CC} -o hw hw.o
hw.o: hw.cpp
  ${CC} -c hw.cpp
clean:
  rm *.o

To remove the .o files:

make clean

Targets

• tinyconfig smallest possible kernel configuration
• allnoconfig answer no to every question when creating a config file

A configure script is responsible for preparing the software build, ensuring dependencies are available, such as a C compiler for C programs. make is invoked after the configure script has done its job. The configure script converts a Makefile.in template into a Makefile. They are not built by hand but packaged by yet another program in the autotools suite, such as autoconf, automake, and others.

A configure.ac file written in m4sh (a combination of m4 macros and shell script) is prepared. The first m4 macro called i AC_INIT, which initializes autoconf:

AC_INIT([helloworld], [0.1], [[email protected]])

The AM_INIT_AUTOMAKE macro is also called because we're using automake:

AM_INIT_AUTOMAKE

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