# Build HTML docs from markdown using pandoc?

%bcond html_docs 1

Name:           gn

# Upstream uses the number of commits in the git history as the version number.

# See gn --version, which outputs something like “1874 (2b683eff)”. The commit

# position and short commit hash in this string come from “git describe HEAD

# --match initial-commit”; see build/gen.py. This means that a complete git

# checkout is required to establish the version number; the information is not

# in the tarball! This is terribly inconvenient. See

# https://bugs.chromium.org/p/gn/issues/detail?id=3.

#

# As a result, it is necessary to use our custom update-version script,

# supplying the new full commit hash as the sole argument or providing no

# arguments to select the latest commit. This will:

#  1. Clone the git repository from the Internet (a substantial download)

#  2. Run build/gen.py to generate last_commit_position.h, the header with

#     version information, and copy it into the same directory as the script

#  3. Modify the commit and access macros and the Version field in this spec

#     file.

#  4. Download the source tarball (spectool -g)

#  5. Update the sources (fedpkg new-sources %%{commit}.tar.gz)

#  6. Stage all changes in git

#  7. Commit the changes

#

# See https://gn.googlesource.com/gn/+log for the latest changes.

%global commit 0a2b8eac80f164f10b2cbc126890db0d295790cd

%global access 20240216

%global shortcommit %(c='%{commit}'; echo "${c:0:12}")

%global position 2146

Version:        %{position}^%{access}git%{shortcommit}

Release:        %autorelease

Summary:        Meta-build system that generates build files for Ninja

# The entire source is BSD-3-Clause, except:

#   - src/base/third_party/icu/ is (Unicode AND ICU); see

#     src/base/third_party/icu/LICENSE and also the header comment in

#     src/base/third_party/icu/icu_utf.h.

#

# Note that src/util/test/gn_test.cc, which is licensed Apache-2.0, does not

# contribute to the binary RPMs, only to the gn_unittests executable, which is

# not installed; you may verify this with:

#   gdb -ex 'set pagination off' -ex 'info sources' gn | grep -F gn_test.cc

License:        BSD-3-Clause AND Unicode AND ICU

URL:            https://gn.googlesource.com/gn

Source0:        %{url}/+archive/%{commit}.tar.gz#/gn-%{shortcommit}.tar.gz

# Generated using script update-version:

Source1:        last_commit_position.h

Source2:        update-version

# Stop overriding optimization flags; not sent upstream because this is

# intentional on their part

Patch:          gn-0153d369-no-O3.patch

# https://fedoraproject.org/wiki/Changes/EncourageI686LeafRemoval

ExcludeArch:    %{ix86}

BuildRequires:  python3-devel

BuildRequires:  ninja-build

BuildRequires:  gcc-c++

# For RPM macros:

BuildRequires:  emacs-common

%if %{with html_docs}

BuildRequires:  pandoc

BuildRequires:  parallel

%endif

BuildRequires:  help2man

Requires:       vim-filesystem

Requires:       python3

Provides:       vim-gn = %{version}-%{release}

Requires:       emacs-filesystem >= %{_emacs_version}

Provides:       emacs-gn = %{version}-%{release}

# src/base/third_party/icu/icu_utf.h:

#

#   This file has the relevant components from ICU copied to handle basic

#   UTF8/16/32 conversions. Components are copied from umachine.h, utf.h,

#   utf8.h, and utf16.h into icu_utf.h.

#

# The forked, bundled ICU components are copied from Chromium. Because of the

# downstream changes (primarily, changing namespaces and symbol prefixes),

# there is no clear path to unbundling.

#

# See src/base/third_party/icu/README.chromium, from which the version number

# is taken.

Provides:       bundled(icu) = 60

%description

GN is a meta-build system that generates build files for Ninja.

%package doc

Summary:        Documentation for GN

BuildArch:      noarch

%description doc

The gn-doc package contains detailed documentation for GN.

%prep

%autosetup -c -n gn-%{commit} -p1

# Use pre-generated last_commit_position.h.

mkdir -p ./out

cp -vp '%{SOURCE1}' ./out

# Copy and rename vim extensions readme for use in the main documentation

# directory.

cp -vp misc/vim/README.md README-vim.md

# Fix shebangs in examples and such.

%py3_shebang_fix .

%build

AR='gcc-ar'; export AR

# Treating warnings as errors is too strict for downstream builds.

#

# Both --use-icf and --use-lto add compiler flags that only work with clang++,

# not with g++. We do get LTO on Fedora anyway, since we respect the

# distribution’s build flags.

%{python3} build/gen.py \

    --allow-warnings \

    --no-last-commit-position \

    --no-strip \

    --no-static-libstdc++

ninja -C out -v

%if %{with html_docs}

# There is a script, misc/help_as_html.py, that generates some HTML help, but

# pandoc does a better job and we can cover more Markdown sources.

find . -type f -name '*.md' | parallel -v pandoc -o '{.}.html' '{}'

%endif

help2man \

    --name='%{summary}' \

    --version-string="gn $(./out/gn --version)" \

    --no-info \

    ./out/gn |

  # Clean up a couple of stray binary bytes in the help output

  tr -d '\302\240' |

  # Format the entries within the sections as tagged paragraphs, and italicise

  # [placeholders in square brackets].

  sed -r -e 's/(^[[:alnum:]_]+:)/.TP\n.B \1\n/' \

      -e 's/\[([^]]+)\]/\\fI[\1]\\fR/g' > out/gn.1

%install

install -t '%{buildroot}%{_bindir}' -D -p out/gn

install -d '%{buildroot}%{_datadir}/vim/vimfiles'

cp -vrp misc/vim/* '%{buildroot}%{_datadir}/vim/vimfiles'

find '%{buildroot}%{_datadir}/vim/vimfiles' \

    -type f -name 'README.*' -print -delete

%py_byte_compile %{python3} '%{buildroot}%{_datadir}/vim/vimfiles/gn-format.py'

install -t '%{buildroot}%{_emacs_sitestartdir}' -D -p -m 0644 misc/emacs/*.el

install -t '%{buildroot}%{_mandir}/man1' -D -m 0644 -p out/gn.1

%check

out/gn_unittests

# Verify consistency of the version header with the spec file

grep -E '^#define[[:blank:]]+LAST_COMMIT_POSITION_NUM[[:blank:]]+'\

'%{position}[[:blank:]]*' \

    'out/last_commit_position.h' >/dev/null

grep -E '^#define[[:blank:]]+LAST_COMMIT_POSITION[[:blank:]]+'\

'"%{position} \(%{shortcommit}\)"[[:blank:]]*' \

    'out/last_commit_position.h' >/dev/null

%files

%license LICENSE

%{_bindir}/gn

%{_mandir}/man1/gn.1*

%{_datadir}/vim/vimfiles/gn-format.py

%{_datadir}/vim/vimfiles/autoload/gn.vim

%{_datadir}/vim/vimfiles/ftdetect/gnfiletype.vim

%{_datadir}/vim/vimfiles/ftplugin/gn.vim

%{_datadir}/vim/vimfiles/syntax/gn.vim

%{_emacs_sitestartdir}/gn-mode.el

%files doc

%license LICENSE src/base/third_party/icu/README.chromium

%doc AUTHORS

%doc OWNERS

%doc README*.md

%if %{with html_docs}

%doc README*.html

%endif

%doc docs/

%doc examples/

%doc infra/

%doc tools/

%changelog

%autochangelog