From 5ec441733dc91370985164c24a94d0a7e90d3aab Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Thu, 23 Jan 2020 14:39:50 +0100
Subject: [PATCH 01/15] compile test program with same compiler as will be used
 to compile sklearn + support icc linux openmp flag

---
 azure-pipelines.yml                       |  1 +
 build_tools/azure/install.sh              | 22 ++++++++++++++----
 build_tools/azure/test_docs.sh            |  4 ++++
 build_tools/azure/test_script.sh          |  4 ++++
 sklearn/_build_utils/openmp_helpers.py    |  4 +++-
 sklearn/_build_utils/pre_build_helpers.py | 28 +++++++++++++++++++++--
 6 files changed, 56 insertions(+), 7 deletions(-)

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index b029a2fd18574..632b093942d26 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -40,6 +40,7 @@ jobs:
         PYTEST_VERSION: '*'
         JOBLIB_VERSION: '*'
         COVERAGE: 'true'
+        BUILD_WITH_ICC: 'true'
 
 - template: build_tools/azure/posix.yml
   parameters:
diff --git a/build_tools/azure/install.sh b/build_tools/azure/install.sh
index 1ef981b5dd6e8..a6f332135f8f8 100755
--- a/build_tools/azure/install.sh
+++ b/build_tools/azure/install.sh
@@ -120,7 +120,21 @@ except ImportError:
 "
 python -m pip list
 
-# Use setup.py instead of `pip install -e .` to be able to pass the -j flag
-# to speed-up the building multicore CI machines.
-python setup.py build_ext --inplace -j 3
-python setup.py develop
+if [[ "$BUILD_WITH_ICC" == "true" ]]; then
+    wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    rm GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    sudo add-apt-repository "deb https://apt.repos.intel.com/oneapi all main"
+    sudo apt-get update
+    sudo apt-get install intel-oneapi-icc
+    source /opt/intel/inteloneapi/setvars.sh
+
+    python setup.py build_ext --compiler=intelem -i -j 3 build_clib --compiler=intelem
+    python setup.py develop
+else
+    # Use setup.py instead of `pip install -e .` to be able to pass the -j flag
+    # to speed-up the building multicore CI machines.
+    python setup.py build_ext --inplace -j 3
+    python setup.py develop
+fi
+
diff --git a/build_tools/azure/test_docs.sh b/build_tools/azure/test_docs.sh
index b3a5ec97c4d6a..fc1bd988cc9b7 100755
--- a/build_tools/azure/test_docs.sh
+++ b/build_tools/azure/test_docs.sh
@@ -8,4 +8,8 @@ elif [[ "$DISTRIB" == "ubuntu" ]]; then
     source $VIRTUALENV/bin/activate
 fi
 
+if [[ "$BUILD_WITH_ICC" == "true" ]]; then
+    source /opt/intel/inteloneapi/setvars.sh
+fi
+
 make test-doc
diff --git a/build_tools/azure/test_script.sh b/build_tools/azure/test_script.sh
index 77a950d86549c..8caaf2bb3ef0f 100755
--- a/build_tools/azure/test_script.sh
+++ b/build_tools/azure/test_script.sh
@@ -8,6 +8,10 @@ elif [[ "$DISTRIB" == "ubuntu" ]] || [[ "$DISTRIB" == "ubuntu-32" ]]; then
     source $VIRTUALENV/bin/activate
 fi
 
+if [[ "$BUILD_WITH_ICC" == "true" ]]; then
+    source /opt/intel/inteloneapi/setvars.sh
+fi
+
 python --version
 python -c "import numpy; print('numpy %s' % numpy.__version__)"
 python -c "import scipy; print('scipy %s' % scipy.__version__)"
diff --git a/sklearn/_build_utils/openmp_helpers.py b/sklearn/_build_utils/openmp_helpers.py
index d4c377c67e05f..63e185debb00e 100644
--- a/sklearn/_build_utils/openmp_helpers.py
+++ b/sklearn/_build_utils/openmp_helpers.py
@@ -1,7 +1,7 @@
 """Helpers for OpenMP support during the build."""
 
 # This code is adapted for a large part from the astropy openmp helpers, which
-# can be found at: https://github.com/astropy/astropy-helpers/blob/master/astropy_helpers/openmp_helpers.py  # noqa
+# can be found at: https://github.com/astropy/extension-helpers/blob/master/extension_helpers/_openmp_helpers.py  # noqa
 
 
 import os
@@ -40,6 +40,8 @@ def get_openmp_flag(compiler):
         # export LDFLAGS="$LDFLAGS -Wl,-rpath,/usr/local/opt/libomp/lib
         #                          -L/usr/local/opt/libomp/lib -lomp"
         return []
+    elif sys.platform == "linux" and "icc" in compiler:
+        return ['-qopenmp']
     # Default flag for GCC and clang:
     return ['-fopenmp']
 
diff --git a/sklearn/_build_utils/pre_build_helpers.py b/sklearn/_build_utils/pre_build_helpers.py
index bc3d83257dd7e..6b495af0faff3 100644
--- a/sklearn/_build_utils/pre_build_helpers.py
+++ b/sklearn/_build_utils/pre_build_helpers.py
@@ -7,14 +7,38 @@
 import textwrap
 import subprocess
 
+from distutils.dist import Distribution
 from distutils.sysconfig import customize_compiler
 from numpy.distutils.ccompiler import new_compiler
 
 
+def _get_compiler():
+    """Get a compiler equivalent to the one that will be used to build sklearn
+
+    Handles compiler specified as follows:
+        - python setup.py build_ext --compiler=<compiler>
+        - CC=<compiler> python setup.py build_ext
+    """
+    dist = Distribution({'script_name': os.path.basename(sys.argv[0]),
+                         'script_args': sys.argv[1:]})
+    dist.parse_config_files()
+    dist.parse_command_line()
+
+    cmd_opts = dist.command_options.get('build_ext')
+    if cmd_opts is not None and 'compiler' in cmd_opts:
+        compiler = cmd_opts['compiler'][1]
+    else:
+        compiler = None
+
+    ccompiler = new_compiler(compiler=compiler)
+    customize_compiler(ccompiler)
+
+    return ccompiler
+
+
 def compile_test_program(code, extra_preargs=[], extra_postargs=[]):
     """Check that some C code can be compiled and run"""
-    ccompiler = new_compiler()
-    customize_compiler(ccompiler)
+    ccompiler = _get_compiler()
 
     # extra_(pre/post)args can be a callable to make it possible to get its
     # value from the compiler

From c57451c8caa9b2dfb998955e422596b0017127f8 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Fri, 24 Jan 2020 13:59:25 +0100
Subject: [PATCH 02/15] trigger ci


From 256be7f0f5a41e9c3db0c3be7664a3e8cfbf90c7 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Fri, 24 Jan 2020 14:27:33 +0100
Subject: [PATCH 03/15] trigger ci


From 7d0d40eb2bdb98d906898d7719d0d3fb5f267447 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 11:15:03 +0100
Subject: [PATCH 04/15] openmp flag for icc on linux and macos

---
 sklearn/_build_utils/openmp_helpers.py | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sklearn/_build_utils/openmp_helpers.py b/sklearn/_build_utils/openmp_helpers.py
index 63e185debb00e..2d1b92c4e7298 100644
--- a/sklearn/_build_utils/openmp_helpers.py
+++ b/sklearn/_build_utils/openmp_helpers.py
@@ -25,8 +25,8 @@ def get_openmp_flag(compiler):
         return ['/Qopenmp']
     elif sys.platform == "win32":
         return ['/openmp']
-    elif sys.platform == "darwin" and ('icc' in compiler or 'icl' in compiler):
-        return ['-openmp']
+    elif sys.platform in ("darwin", "linux") and "icc" in compiler:
+        return ['-qopenmp']
     elif sys.platform == "darwin" and 'openmp' in os.getenv('CPPFLAGS', ''):
         # -fopenmp can't be passed as compile flag when using Apple-clang.
         # OpenMP support has to be enabled during preprocessing.
@@ -40,8 +40,6 @@ def get_openmp_flag(compiler):
         # export LDFLAGS="$LDFLAGS -Wl,-rpath,/usr/local/opt/libomp/lib
         #                          -L/usr/local/opt/libomp/lib -lomp"
         return []
-    elif sys.platform == "linux" and "icc" in compiler:
-        return ['-qopenmp']
     # Default flag for GCC and clang:
     return ['-fopenmp']
 

From 3068d0009e8c40074ece1a911c733e580820657e Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:19:32 +0100
Subject: [PATCH 05/15] icc on cron job

---
 .travis.yml                       | 10 ++++++++--
 build_tools/azure/install.sh      | 22 ++++------------------
 build_tools/azure/test_docs.sh    |  4 ----
 build_tools/azure/test_script.sh  |  4 ----
 build_tools/travis/install.sh     | 18 ++++++++++++++++++
 build_tools/travis/test_docs.sh   |  6 ++++++
 build_tools/travis/test_script.sh |  6 ++++++
 7 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 9fda90f71a7c0..758a53f18b04b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,8 +22,14 @@ matrix:
     # installed from their CI wheels in a virtualenv with the Python
     # interpreter provided by travis.
     -  python: 3.7
-       env: CHECK_WARNINGS="true"
-       if: type = cron OR commit_message =~ /\[scipy-dev\]/
+        env: CHECK_WARNINGS="true"
+        if: type = cron OR commit_message =~ /\[scipy-dev\]/
+    
+    - python: 3.7
+        env:
+          - CHECK_WARNING="true"
+          - BUILD_WITH_ICC="true"
+        if: type = cron OR commit_message =~ /\[scipy-dev\]/
 
 install: source build_tools/travis/install.sh
 script:
diff --git a/build_tools/azure/install.sh b/build_tools/azure/install.sh
index a6f332135f8f8..1ef981b5dd6e8 100755
--- a/build_tools/azure/install.sh
+++ b/build_tools/azure/install.sh
@@ -120,21 +120,7 @@ except ImportError:
 "
 python -m pip list
 
-if [[ "$BUILD_WITH_ICC" == "true" ]]; then
-    wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
-    sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
-    rm GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
-    sudo add-apt-repository "deb https://apt.repos.intel.com/oneapi all main"
-    sudo apt-get update
-    sudo apt-get install intel-oneapi-icc
-    source /opt/intel/inteloneapi/setvars.sh
-
-    python setup.py build_ext --compiler=intelem -i -j 3 build_clib --compiler=intelem
-    python setup.py develop
-else
-    # Use setup.py instead of `pip install -e .` to be able to pass the -j flag
-    # to speed-up the building multicore CI machines.
-    python setup.py build_ext --inplace -j 3
-    python setup.py develop
-fi
-
+# Use setup.py instead of `pip install -e .` to be able to pass the -j flag
+# to speed-up the building multicore CI machines.
+python setup.py build_ext --inplace -j 3
+python setup.py develop
diff --git a/build_tools/azure/test_docs.sh b/build_tools/azure/test_docs.sh
index fc1bd988cc9b7..b3a5ec97c4d6a 100755
--- a/build_tools/azure/test_docs.sh
+++ b/build_tools/azure/test_docs.sh
@@ -8,8 +8,4 @@ elif [[ "$DISTRIB" == "ubuntu" ]]; then
     source $VIRTUALENV/bin/activate
 fi
 
-if [[ "$BUILD_WITH_ICC" == "true" ]]; then
-    source /opt/intel/inteloneapi/setvars.sh
-fi
-
 make test-doc
diff --git a/build_tools/azure/test_script.sh b/build_tools/azure/test_script.sh
index 8caaf2bb3ef0f..77a950d86549c 100755
--- a/build_tools/azure/test_script.sh
+++ b/build_tools/azure/test_script.sh
@@ -8,10 +8,6 @@ elif [[ "$DISTRIB" == "ubuntu" ]] || [[ "$DISTRIB" == "ubuntu-32" ]]; then
     source $VIRTUALENV/bin/activate
 fi
 
-if [[ "$BUILD_WITH_ICC" == "true" ]]; then
-    source /opt/intel/inteloneapi/setvars.sh
-fi
-
 python --version
 python -c "import numpy; print('numpy %s' % numpy.__version__)"
 python -c "import scipy; print('scipy %s' % scipy.__version__)"
diff --git a/build_tools/travis/install.sh b/build_tools/travis/install.sh
index 6bb15b3f539e1..f20bed2a9b2e0 100755
--- a/build_tools/travis/install.sh
+++ b/build_tools/travis/install.sh
@@ -60,6 +60,24 @@ python --version
 python -c "import numpy; print('numpy %s' % numpy.__version__)"
 python -c "import scipy; print('scipy %s' % scipy.__version__)"
 
+if [[ "$BUILD_WITH_ICC" == "true" ]]; then
+    wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    rm GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    sudo add-apt-repository "deb https://apt.repos.intel.com/oneapi all main"
+    sudo apt-get update
+    sudo apt-get install intel-oneapi-icc
+    source /opt/intel/inteloneapi/setvars.sh
+
+    # The build_clib command is implicitly used to build libsvm-skl. To compile
+    # with a different compiler we also need to specify the compiler for this
+    # command.
+    python setup.py build_ext --compiler=intelem -i -j 3 build_clib --compiler=intelem
+else
+    # Use setup.py instead of `pip install -e .` to be able to pass the -j flag
+    # to speed-up the building multicore CI machines.
+    python setup.py build_ext --inplace -j 3
+
 python setup.py develop
 
 ccache --show-stats
diff --git a/build_tools/travis/test_docs.sh b/build_tools/travis/test_docs.sh
index d43b480fa79f9..d70aca3249321 100755
--- a/build_tools/travis/test_docs.sh
+++ b/build_tools/travis/test_docs.sh
@@ -3,4 +3,10 @@
 set -e
 set -x
 
+if [[ "$BUILD_WITH_ICC" == "true" ]]; then
+    # the tools in the oneAPI toolkits are configured via environment variables
+    # which are also required at runtime.
+    source /opt/intel/inteloneapi/setvars.sh
+fi
+
 make test-doc
diff --git a/build_tools/travis/test_script.sh b/build_tools/travis/test_script.sh
index f13e0f1bbb2fa..ed111d80a5c12 100755
--- a/build_tools/travis/test_script.sh
+++ b/build_tools/travis/test_script.sh
@@ -20,6 +20,12 @@ except ImportError:
 "
 python -c "import multiprocessing as mp; print('%d CPUs' % mp.cpu_count())"
 
+if [[ "$BUILD_WITH_ICC" == "true" ]]; then
+    # the tools in the oneAPI toolkits are configured via environment variables
+    # which are also required at runtime.
+    source /opt/intel/inteloneapi/setvars.sh
+fi
+
 run_tests() {
     TEST_CMD="pytest --showlocals --durations=20 --pyargs"
 

From a8d4df91b3544dea8c4838bdbca331d88ffd7b2e Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:20:08 +0100
Subject: [PATCH 06/15] tst [scipy-dev]


From 23eb9f2d6073175ffec6927908cd1e5d6d97fcfd Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:26:40 +0100
Subject: [PATCH 07/15] [scipy-dev] tst


From 51805427289f5fb9b06a0f23ceeaefc11915f117 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:29:01 +0100
Subject: [PATCH 08/15] [scipy-dev] cln

---
 azure-pipelines.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 632b093942d26..b029a2fd18574 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -40,7 +40,6 @@ jobs:
         PYTEST_VERSION: '*'
         JOBLIB_VERSION: '*'
         COVERAGE: 'true'
-        BUILD_WITH_ICC: 'true'
 
 - template: build_tools/azure/posix.yml
   parameters:

From fa29257dd2eca9a6ae9fd1097fa8aae285e04454 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:39:29 +0100
Subject: [PATCH 09/15] [scipy-dev] fix yml

---
 .travis.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 758a53f18b04b..cdcde79927bed 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,14 +21,14 @@ matrix:
     # Linux environment to test scikit-learn against numpy and scipy master
     # installed from their CI wheels in a virtualenv with the Python
     # interpreter provided by travis.
-    -  python: 3.7
+    - python: 3.7
         env: CHECK_WARNINGS="true"
         if: type = cron OR commit_message =~ /\[scipy-dev\]/
     
     - python: 3.7
         env:
-          - CHECK_WARNING="true"
-          - BUILD_WITH_ICC="true"
+        - CHECK_WARNING="true"
+        - BUILD_WITH_ICC="true"
         if: type = cron OR commit_message =~ /\[scipy-dev\]/
 
 install: source build_tools/travis/install.sh

From b3b3a71e0591f2b97ed8d2e151134afb5ab57f99 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:42:41 +0100
Subject: [PATCH 10/15] [scipy-dev] tst

---
 .travis.yml | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index cdcde79927bed..d9acb27863572 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,9 +26,8 @@ matrix:
         if: type = cron OR commit_message =~ /\[scipy-dev\]/
     
     - python: 3.7
-        env:
-        - CHECK_WARNING="true"
-        - BUILD_WITH_ICC="true"
+        env: CHECK_WARNING="true"
+        # - BUILD_WITH_ICC="true"
         if: type = cron OR commit_message =~ /\[scipy-dev\]/
 
 install: source build_tools/travis/install.sh

From 386de12d8cd1babaa696e99935e780e714845c32 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:44:17 +0100
Subject: [PATCH 11/15] tst [scipy-dev]

---
 .travis.yml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index d9acb27863572..436abab44607b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,10 +25,10 @@ matrix:
         env: CHECK_WARNINGS="true"
         if: type = cron OR commit_message =~ /\[scipy-dev\]/
     
-    - python: 3.7
-        env: CHECK_WARNING="true"
-        # - BUILD_WITH_ICC="true"
-        if: type = cron OR commit_message =~ /\[scipy-dev\]/
+    # - python: 3.7
+    #     env: CHECK_WARNING="true"
+    #     # - BUILD_WITH_ICC="true"
+    #     if: type = cron OR commit_message =~ /\[scipy-dev\]/
 
 install: source build_tools/travis/install.sh
 script:

From 40b3415b298fe1104f18e7fc57e09f223fbbd27c Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:45:41 +0100
Subject: [PATCH 12/15] [scipy-dev] tst

---
 .travis.yml | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 436abab44607b..ff8c6b7d2f947 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,13 +22,14 @@ matrix:
     # installed from their CI wheels in a virtualenv with the Python
     # interpreter provided by travis.
     - python: 3.7
-        env: CHECK_WARNINGS="true"
-        if: type = cron OR commit_message =~ /\[scipy-dev\]/
+      env: CHECK_WARNINGS="true"
+      if: type = cron OR commit_message =~ /\[scipy-dev\]/
     
-    # - python: 3.7
-    #     env: CHECK_WARNING="true"
-    #     # - BUILD_WITH_ICC="true"
-    #     if: type = cron OR commit_message =~ /\[scipy-dev\]/
+    - python: 3.7
+      env:
+        - CHECK_WARNING="true"
+        - BUILD_WITH_ICC="true"
+      if: type = cron OR commit_message =~ /\[scipy-dev\]/
 
 install: source build_tools/travis/install.sh
 script:

From 874ed98fea5d1ef752140be534502033acbc7014 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Mon, 27 Jan 2020 15:49:48 +0100
Subject: [PATCH 13/15] [scipy-dev] fix install script

---
 build_tools/travis/install.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/build_tools/travis/install.sh b/build_tools/travis/install.sh
index f20bed2a9b2e0..c6a34af23d549 100755
--- a/build_tools/travis/install.sh
+++ b/build_tools/travis/install.sh
@@ -77,6 +77,7 @@ else
     # Use setup.py instead of `pip install -e .` to be able to pass the -j flag
     # to speed-up the building multicore CI machines.
     python setup.py build_ext --inplace -j 3
+fi
 
 python setup.py develop
 

From 11a2b55bc4c26c097eab395a5e27712bde859f15 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Tue, 4 Feb 2020 10:43:45 +0100
Subject: [PATCH 14/15] support config_cc

---
 sklearn/_build_utils/pre_build_helpers.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sklearn/_build_utils/pre_build_helpers.py b/sklearn/_build_utils/pre_build_helpers.py
index 6b495af0faff3..322a442ddee39 100644
--- a/sklearn/_build_utils/pre_build_helpers.py
+++ b/sklearn/_build_utils/pre_build_helpers.py
@@ -10,6 +10,7 @@
 from distutils.dist import Distribution
 from distutils.sysconfig import customize_compiler
 from numpy.distutils.ccompiler import new_compiler
+from numpy.distutils.command.config_compiler import config_cc
 
 
 def _get_compiler():
@@ -20,7 +21,8 @@ def _get_compiler():
         - CC=<compiler> python setup.py build_ext
     """
     dist = Distribution({'script_name': os.path.basename(sys.argv[0]),
-                         'script_args': sys.argv[1:]})
+                         'script_args': sys.argv[1:],
+                         'cmdclass': {'config_cc': config_cc}})
     dist.parse_config_files()
     dist.parse_command_line()
 

From 661fa48b0b7e9c55e660e633959ecf8efc31b8fe Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Thu, 6 Feb 2020 14:51:11 +0100
Subject: [PATCH 15/15] instructions to build with ICC using oneAPI on Linux

---
 .travis.yml                              |  3 +-
 doc/developers/advanced_installation.rst | 50 ++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index ff8c6b7d2f947..85c017961afaa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,11 +25,12 @@ matrix:
       env: CHECK_WARNINGS="true"
       if: type = cron OR commit_message =~ /\[scipy-dev\]/
     
+    # As above but build scikit-learn with Intel C compiler (ICC).
     - python: 3.7
       env:
         - CHECK_WARNING="true"
         - BUILD_WITH_ICC="true"
-      if: type = cron OR commit_message =~ /\[scipy-dev\]/
+      if: type = cron OR commit_message =~ /\[icc-build\]/
 
 install: source build_tools/travis/install.sh
 script:
diff --git a/doc/developers/advanced_installation.rst b/doc/developers/advanced_installation.rst
index 8fd0f9ecf0273..1ddc26bf0434c 100644
--- a/doc/developers/advanced_installation.rst
+++ b/doc/developers/advanced_installation.rst
@@ -382,3 +382,53 @@ the base system and these steps will not be necessary.
 .. _Homebrew: https://brew.sh
 .. _virtualenv: https://docs.python.org/3/tutorial/venv.html
 .. _conda environment: https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html
+
+Alternative compilers
+=====================
+
+The command::
+
+    pip install --verbose --editable .
+
+will build scikit-learn using your default C/C++ compiler. If you want to build
+scikit-learn with another compiler handled by ``distutils`` or by
+``numpy.distutils``, use the following command::
+
+    python setup.py build_ext --compiler=<compiler> -i build_clib --compiler=<compiler>
+
+To see the list of available compilers run::
+
+    python setup.py build_ext --help-compiler
+
+If your compiler is not listed here, you can specify it via the ``CC`` and
+``LDSHARED`` environment variables (does not work on windows)::
+
+    CC=<compiler> LDSHARED="<compiler> -shared" python setup.py build_ext -i
+
+Building with Intel C Compiler (ICC) using oneAPI on Linux
+----------------------------------------------------------
+
+Intel provides access to all of its oneAPI toolkits and packages through a
+public APT repository. First you need to get and install the public key of this
+repository::
+
+    wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+    rm GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+
+Then, add the oneAPI repository to your APT repositories::
+
+    sudo add-apt-repository "deb https://apt.repos.intel.com/oneapi all main"
+    sudo apt-get update
+
+Install ICC, packaged under the name ``intel-oneapi-icc``::
+
+    sudo apt-get install intel-oneapi-icc
+
+Before using ICC, you need to set up environment variables::
+
+    source /opt/intel/inteloneapi/setvars.sh
+
+Finally, you can build scikit-learn. For example on Linux x86_64::
+
+    python setup.py build_ext --compiler=intelem -i build_clib --compiler=intelem