Final tweaks

* note on alloca()
* fix zz_mul(u, u, u)
* add test for builds with --enable-alloca
* use $PREFIX

Author: skirpichev

.github/workflows/ci.yml

@@ -19,14 +19,27 @@ jobs:
       - uses: actions/checkout@v5
       - run: sudo apt-get update
       - run: sudo apt-get install lcov texlive
+      - name: Cache GNU GMP builds
+        id: cache-gmp
+        uses: actions/cache@v4
+        with:
+          path: .local
+          key: ${{ matrix.os }}-${{ hashFiles('scripts/*') }}
       - run: sh scripts/cibw_before_all.sh
+        if: steps.cache-gmp.outputs.cache-hit != 'true'
       - run: autoreconf -if
       - run: ./configure -q --enable-gcov
+        env:
+          PKG_CONFIG_PATH: ${{ github.workspace }}/.local/lib/pkgconfig
       - run: make -s
       - run: make -s check
+        env:
+          LD_LIBRARY_PATH: ${{ github.workspace }}/.local/lib
       - run: lcov --capture --directory . --output-file coverage.info
       - run: genhtml coverage.info --output-directory coverage
       - run: make -s distcheck
+        env:
+          LD_LIBRARY_PATH: ${{ github.workspace }}/.local/lib
       - uses: actions/upload-artifact@v4
         with:
           name: coverage

doc/zz.texi

@@ -83,6 +83,10 @@ return codes are supported:
 @item @code{ZZ_BUF}: Buffer overflow, supplied buffer too small.
 @end itemize
 
+Please note, that the GNU GMP library must be compiled with the
+@option{--disable-alloca} configure option to prevent using alloca() for temporary
+workspace allocation (and use the heap instead).
+
 @node Functions, References, Introduction, Top
 @chapter Functions
 
@@ -332,11 +336,11 @@ Set @var{w} to the least common multiple of @var{u} and @var{v}.
 @section Combinatorics
 
 @deftypefun zz_err zz_fac (uint64_t @var{u}, zz_t *@var{v})
-Set @var{v} to @math{u!}.
+Set @var{v} to @math{@var{u}!}.
 @end deftypefun
 
 @deftypefun zz_err zz_fac2 (uint64_t @var{u}, zz_t *@var{v})
-Set @var{v} to @math{u!!}.
+Set @var{v} to @math{@var{u}!!}.
 @end deftypefun
 
 @deftypefun zz_err zz_fib (uint64_t @var{u}, zz_t *@var{v})

scripts/cibw_before_all.sh

@@ -27,6 +27,7 @@ rm config.guess && mv configfsf.guess config.guess && chmod +x config.guess
             --disable-static \
             --with-pic \
             --disable-alloca \
+            --prefix=$PREFIX \
             --quiet
 
-sudo make --silent all install
+make --silent all install

tests/t-fac.c

@@ -58,6 +58,18 @@ int main(void)
         perror("setrlimit");
         return 1;
     }
+    /* to trigger crash for GMP builds with alloca() enabled */
+    if (getrlimit(RLIMIT_STACK, &old)) {
+        perror("getrlimit");
+        return 1;
+    }
+    new.rlim_max = old.rlim_max;
+    new.rlim_cur = 128*1000;
+    if (setrlimit(RLIMIT_STACK, &new)) {
+        perror("setrlimit");
+        return 1;
+    }
     check_fac_outofmem();
+    zz_finish();
     return 0;
 }

tests/t-mul.c

@@ -116,5 +116,6 @@ int main(void)
 #if HAVE_PTHREAD_H
     check_square_outofmem_pthread();
 #endif
+    zz_finish();
     return 0;
 }

zz.c

@@ -995,7 +995,7 @@ zz_mul(const zz_t *u, const zz_t *v, zz_t *w)
             /* LCOV_EXCL_STOP */
         }
 
-        zz_err ret = zz_mul(&tmp, v, w);
+        zz_err ret = u == v ? zz_mul(&tmp, &tmp, w) : zz_mul(&tmp, v, w);
 
         zz_clear(&tmp);
         return ret;