Require raqm>=0.2 (extern C in header).

Author: anntzer

README.rst

@@ -55,7 +55,7 @@ As usual, install using pip::
 
    python -mpip install mplcairo
 
-mplcairo can use Raqm_ for complex text layout if it is available.  Refer to
+mplcairo can use Raqm_ (≥0.2) for complex text layout if it is available.  Refer to
 the instructions on that project's website for installation on Linux and OSX.
 You may want to look at https://github.com/HOST-Oman/libraqm-cmake for Windows
 build scripts.
@@ -92,11 +92,6 @@ can be built and installed using any of the standard commands (``pip wheel
 --no-deps .``, ``pip install .``, ``pip install -e .`` and ``python setup.py
 build_ext -i`` being the most relevant ones).
 
-If the ``MPLCAIRO_USE_LIBRAQM`` environment variable is set, the build also
-uses Raqm to perform complex text layout (right-to-left scripts, etc.).  An
-installation of Raqm is required; run ``setup.py`` for instructions for Unix
-OSes.
-
 Unix
 ----
 
@@ -116,8 +111,8 @@ The following additional dependencies are required:
   On Linux, they can also be installed with your distribution's package manager
   (Debian/Ubuntu: ``libcairo2-dev``, Fedora: ``cairo-devel``).
 
-Raqm headers are also needed, but will be automatically downloaded if not
-found.
+Raqm (≥0.2) headers are also needed, but will be automatically downloaded if
+not found.
 
 Linux
 `````
@@ -133,9 +128,9 @@ will be mis-linked and fail to load.
 
 The manylinux wheel is built using ``tools/build-manylinux.sh``.
 
-**NOTE**: On Arch Linux, the python-pillow 5.0.0-1 (Arch) package includes an
-invalid version ``raqm.h`` (https://bugs.archlinux.org/task/57492) and must not
-be installed while building a Raqm-enabled version of mplcairo using the system
+**NOTE**: On Arch Linux, the python-pillow (Arch) package includes an invalid
+version of ``raqm.h`` (https://bugs.archlinux.org/task/57492) and must not be
+installed while building a Raqm-enabled version of mplcairo using the system
 Python, even in a virtualenv (it can be installed when *using* mplcairo without
 causing any problems).  One solution is to temporarily uninstall the package;
 another one is to package it yourself using e.g. pypi2pkgbuild_.

setup.py

@@ -21,14 +21,22 @@
 from setupext import Extension, build_ext, find_packages, setup
 
 
+MIN_CAIRO_VERSION = "1.11.4"
+MIN_RAQM_VERSION = "0.2.0"
 RAQM_TAG = "v0.5.0"
 
 
 def get_pkg_config(info, lib):
-    if os.environ.get("MANYLINUX") and info == "--cflags":
-        return ["-static-libgcc", "-static-libstdc++",
-                "-I/usr/include/cairo",
-                "-I/usr/include/freetype2"]
+    if os.environ.get("MANYLINUX"):
+        if info.startswith("--atleast-version"):
+            if lib == "raqm":
+                raise FileNotFoundError  # Trigger the header download.
+            else:
+                return ""
+        if info == "--cflags":
+            return ["-static-libgcc", "-static-libstdc++",
+                    "-I/usr/include/cairo",
+                    "-I/usr/include/freetype2"]
     return shlex.split(subprocess.check_output(["pkg-config", info, lib],
                                                universal_newlines=True))
 
@@ -77,7 +85,8 @@ def build_extensions(self):
              pybind11.get_include(), pybind11.get_include(user=True)])
 
         try:
-            get_pkg_config("--exists", "raqm")
+            get_pkg_config(
+                "--atleast-version={}".format(MIN_RAQM_VERSION), "raqm")
         except (FileNotFoundError, CalledProcessError):
             with urllib.request.urlopen(
                     "https://raw.githubusercontent.com/HOST-Oman/libraqm/"
@@ -87,6 +96,8 @@ def build_extensions(self):
 
         if sys.platform == "linux":
             import cairo
+            get_pkg_config(
+                "--atleast-version={}".format(MIN_CAIRO_VERSION), "cairo")
             ext.include_dirs += [cairo.get_include()]
             ext.extra_compile_args += (
                 ["-std=c++1z", "-fvisibility=hidden", "-flto",
@@ -103,6 +114,8 @@ def build_extensions(self):
 
         elif sys.platform == "darwin":
             import cairo
+            get_pkg_config(
+                "--atleast-version={}".format(MIN_CAIRO_VERSION), "cairo")
             ext.include_dirs += [cairo.get_include()]
             ext.extra_compile_args += (
                 # version-min=10.9 avoids deprecation warning wrt. libstdc++.

src/_feature_tests.cpp

@@ -7,8 +7,3 @@
 #if defined __clang__ && !defined _LIBCPP_VERSION
   #error "Compilation with Clang requires using libc++, not libstdc++."
 #endif
-
-#if !__has_include(<raqm.h>)
-  #error "Please download raqm.h and place it in the include/ directory.  " \
-         "You may want to use tools/download_raqm_header.py."
-#endif