From ca3417b8d605ccdb2e6c516c5e0c79180381627c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rapha=C3=ABl=20M=C3=A9lotte?= <raphael.melotte@mind.be>
Date: Sun, 4 Feb 2024 16:13:45 +0100
Subject: [PATCH] pipcl.py: allow providing python-config externally
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When cross-compiling (e.g. using Buildroot), the python-config
executable that resides next to the host python executable provides
incorrect includes (the ones for the host).

Since the correct path to python-config cannot be guessed, add an
additional environment variable to allow setting the path to the
correct python-config executable externally.

Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
Upstream: https://github.com/pymupdf/PyMuPDF/commit/3a214b0c144d86fd1329b26030f6b9f2a6b27020
---
 pipcl.py | 72 +++++++++++++++++++++++++++++---------------------------
 setup.py |  3 +++
 2 files changed, 40 insertions(+), 35 deletions(-)

diff --git a/pipcl.py b/pipcl.py
index 209f660..c154774 100644
--- a/pipcl.py
+++ b/pipcl.py
@@ -1789,43 +1789,45 @@ class PythonFlags:
             self.ldflags = f'-L {_lib_dir}'
 
         else:
-            # We use python-config which appears to work better than pkg-config
-            # because it copes with multiple installed python's, e.g.
-            # manylinux_2014's /opt/python/cp*-cp*/bin/python*.
-            #
-            # But... on non-macos it seems that we should not attempt to specify
-            # libpython on the link command. The manylinux docker containers
-            # don't actually contain libpython.so, and it seems that this
-            # deliberate. And the link command runs ok.
-            #
-            python_exe = os.path.realpath( sys.executable)
-            if darwin():
-                # Basic install of dev tools with `xcode-select --install` doesn't
-                # seem to provide a `python3-config` or similar, but there is a
-                # `python-config.py` accessible via sysconfig.
+            python_config = os.environ.get("PYMUPDF_PYTHON_CONFIG")
+            if not python_config:
+                # We use python-config which appears to work better than pkg-config
+                # because it copes with multiple installed python's, e.g.
+                # manylinux_2014's /opt/python/cp*-cp*/bin/python*.
                 #
-                # We try different possibilities and use the last one that
-                # works.
+                # But... on non-macos it seems that we should not attempt to specify
+                # libpython on the link command. The manylinux docker containers
+                # don't actually contain libpython.so, and it seems that this
+                # deliberate. And the link command runs ok.
                 #
-                python_config = None
-                for pc in (
-                        f'python3-config',
-                        f'{sys.executable} {sysconfig.get_config_var("srcdir")}/python-config.py',
-                        f'{python_exe}-config',
-                        ):
-                    e = subprocess.run(
-                            f'{pc} --includes',
-                            shell=1,
-                            stdout=subprocess.DEVNULL,
-                            stderr=subprocess.DEVNULL,
-                            check=0,
-                            ).returncode
-                    log1(f'{e=} from {pc!r}.')
-                    if e == 0:
-                        python_config = pc
-                assert python_config, f'Cannot find python-config'
-            else:
-                python_config = f'{python_exe}-config'
+                python_exe = os.path.realpath( sys.executable)
+                if darwin():
+                    # Basic install of dev tools with `xcode-select --install` doesn't
+                    # seem to provide a `python3-config` or similar, but there is a
+                    # `python-config.py` accessible via sysconfig.
+                    #
+                    # We try different possibilities and use the last one that
+                    # works.
+                    #
+                    python_config = None
+                    for pc in (
+                            f'python3-config',
+                            f'{sys.executable} {sysconfig.get_config_var("srcdir")}/python-config.py',
+                            f'{python_exe}-config',
+                            ):
+                        e = subprocess.run(
+                                f'{pc} --includes',
+                                shell=1,
+                                stdout=subprocess.DEVNULL,
+                                stderr=subprocess.DEVNULL,
+                                check=0,
+                                ).returncode
+                        log1(f'{e=} from {pc!r}.')
+                        if e == 0:
+                            python_config = pc
+                    assert python_config, f'Cannot find python-config'
+                else:
+                    python_config = f'{python_exe}-config'
             log1(f'Using {python_config=}.')
             try:
                 self.includes = run( f'{python_config} --includes', capture=1).strip()
diff --git a/setup.py b/setup.py
index 23a5c78..4b3b5c7 100755
--- a/setup.py
+++ b/setup.py
@@ -36,6 +36,9 @@ Environmental variables:
         PYMUPDF_MUPDF_LIB
             Directory containing MuPDF libraries, (libmupdf.so,
             libmupdfcpp.so).
+
+        PYMUPDF_PYTHON_CONFIG
+            Optional path to python-config.
     
     PYMUPDF_SETUP_IMPLEMENTATIONS
         Must be one of 'a', 'b', 'ab'. If unset we use 'ab'.
-- 
2.41.0