Use hypothesis in test_factorial_outofmemory()

That trigger crashes in alloca-enabled builds.

Closes #115

.github/workflows/coverage.yml

@@ -17,16 +17,20 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - run: |
           sudo apt-get update
-          sudo apt-get install libgmp-dev
           sudo apt-get install lcov
+      - run: bash scripts/cibw_before_all.sh
       - run: pip install --upgrade pip setuptools setuptools_scm
       - run: pip --verbose install --editable .[tests]
-      - run: |
+      - name: Build and run coverage tests
+        run: |
           python setup.py clean
-          CFLAGS="-coverage" python setup.py develop
+          python setup.py develop
           pytest --hypothesis-profile=default
           lcov --capture --directory . --no-external \
               --output-file build/coverage-${{ matrix.python-version }}.info
+        env:
+          CFLAGS: -coverage
+          LD_LIBRARY_PATH: .local/lib/
       - uses: actions/upload-artifact@v4
         with:
           name: coverage-${{ matrix.python-version }}

.github/workflows/test.yml

@@ -17,7 +17,6 @@ jobs:
         python-version: [3.9, '3.10', pypy3.10-nightly, 3.11, 3.12, 3.13, 3.14]
     runs-on: ubuntu-24.04
     env:
-      CFLAGS: -Wpedantic -Werror -std=c17
       PYTEST_ADDOPTS: --verbose
     steps:
       - uses: actions/checkout@v4
@@ -27,12 +26,14 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true
-      - run: |
-          sudo apt-get update
-          sudo apt-get install libgmp-dev
+      - run: bash scripts/cibw_before_all.sh
       - run: pip install --upgrade pip
       - run: pip --verbose install --editable .[tests]
+        env:
+          CFLAGS: -Wpedantic -Werror -std=c17
       - run: pytest
+        env:
+          LD_LIBRARY_PATH: .local/lib/
   macos:
     needs:
       - linux

README.rst

@@ -10,6 +10,15 @@ also few functions (factorial, gcd and isqrt), compatible with the stdlib's
 module math.
 
 
+Warning on alloca
+-----------------
+
+Most GMP packages enable using alloca() for temporary workspace allocation.
+This module can't prevent a crash in case of a stack overflow.  To avoid this,
+you should compile the GMP library with '--disable-alloca' configure option to
+use rather the heap for all temporary allocations.
+
+
 Motivation
 ----------
 

scripts/cibw_before_all.sh

@@ -19,6 +19,7 @@ rm config.guess && mv configfsf.guess config.guess && chmod +x config.guess
             --enable-shared \
             --disable-static \
             --with-pic \
+            --disable-alloca \
             --prefix=$PREFIX -q
 make -j6 -s
 make -s install

tests/test_functions.py

@@ -1,5 +1,6 @@
 import math
 import platform
+import resource
 
 import pytest
 from gmp import factorial, gcd, isqrt, mpz
@@ -25,22 +26,18 @@ def test_factorial(x):
                     reason="FIXME: setrlimit fails with ValueError on MacOS")
 @pytest.mark.skipif(platform.python_implementation() == "PyPy",
                     reason="XXX: bug in PyNumber_ToBase()?")
-def test_factorial_outofmemory():
-    import random
-    import resource
-
-    for _ in range(100):
-        soft, hard = resource.getrlimit(resource.RLIMIT_AS)
-        resource.setrlimit(resource.RLIMIT_AS, (1024*64*1024, hard))
-        a = random.randint(12811, 24984)
-        a = mpz(a)
-        while True:
-            try:
-                factorial(a)
-                a *= 2
-            except MemoryError:
-                break
-        resource.setrlimit(resource.RLIMIT_AS, (soft, hard))
+@given(integers(min_value=12811, max_value=24984))
+def test_factorial_outofmemory(x):
+    soft, hard = resource.getrlimit(resource.RLIMIT_AS)
+    resource.setrlimit(resource.RLIMIT_AS, (1024*32*1024, hard))
+    a = mpz(x)
+    while True:
+        try:
+            factorial(a)
+            a *= 2
+        except MemoryError:
+            break
+    resource.setrlimit(resource.RLIMIT_AS, (soft, hard))
 
 
 @given(integers(), integers())

tests/test_mpz.py

@@ -2,6 +2,7 @@
 import operator
 import pickle
 import platform
+import resource
 import string
 import sys
 import warnings
@@ -776,8 +777,6 @@ def test_pickle(protocol, x):
 @example(249846727467293)
 @example(1292734994793)
 def test_outofmemory(x):
-    import resource
-
     soft, hard = resource.getrlimit(resource.RLIMIT_AS)
     resource.setrlimit(resource.RLIMIT_AS, (1024*32*1024, hard))
     mx = mpz(x)