From c0caa79a2aa6ac5b358f30719ff80ee2c6db51f7 Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Mon, 3 Nov 2025 12:06:15 +0100
Subject: [PATCH] Check for feenableexcept() explicitly

musl provides <fenv.h>, but not the non-standard feenableexcept()
function, so using feenableexcept() whenever <fenv.h> was present
caused build failures on musl.  Instead, explicitly check for the
non-standard function we want to use.
---
 configure.ac         | 2 +-
 tests/v17_tests.c    | 6 +++---
 tests/v27ter_tests.c | 6 +++---
 tests/v29_tests.c    | 6 +++---
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index fa87245..a8864d8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -186,6 +186,7 @@ AC_CHECK_FUNCS([strstr])
 AC_CHECK_FUNCS([strtol])
 AC_CHECK_FUNCS([gettimeofday])
 AC_CHECK_FUNCS([drand48])
+AC_CHECK_FUNCS([feenableexcept])
 
 AC_HEADER_SYS_WAIT
 
@@ -209,7 +210,6 @@ AC_CHECK_HEADERS([sys/select.h])
 AC_CHECK_HEADERS([sys/ioctl.h])
 AC_CHECK_HEADERS([sys/fcntl.h])
 AC_CHECK_HEADERS([sndfile.h])
-AC_CHECK_HEADERS([fenv.h])
 AC_CHECK_HEADERS([fftw3.h], , [AC_CHECK_HEADERS([fftw.h])])
 AC_CHECK_HEADERS([pcap.h])
 AC_CHECK_HEADERS([pthread.h])
diff --git a/tests/v17_tests.c b/tests/v17_tests.c
index 17c7fcb..411396c 100644
--- a/tests/v17_tests.c
+++ b/tests/v17_tests.c
@@ -59,7 +59,7 @@ display of modem status is maintained.
 #include <string.h>
 #include <sndfile.h>
 #include <signal.h>
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
 #define __USE_GNU
 #include <fenv.h>
 #endif
@@ -263,7 +263,7 @@ static void qam_report(void *user_data, const complexf_t *constel, const complex
 }
 /*- End of function --------------------------------------------------------*/
 
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
 static void sigfpe_handler(int sig_num, siginfo_t *info, void *data)
 {
     switch (sig_num)
@@ -425,7 +425,7 @@ int main(int argc, char *argv[])
     inhandle = NULL;
     outhandle = NULL;
 
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
     fpe_trap_setup();
 #endif
 
diff --git a/tests/v27ter_tests.c b/tests/v27ter_tests.c
index 14b06f8..f0559a4 100644
--- a/tests/v27ter_tests.c
+++ b/tests/v27ter_tests.c
@@ -58,7 +58,7 @@ display of modem status is maintained.
 #include <string.h>
 #include <sndfile.h>
 #include <signal.h>
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
 #define __USE_GNU
 #include <fenv.h>
 #endif
@@ -286,7 +286,7 @@ static void qam_report(void *user_data, const complexf_t *constel, const complex
 }
 /*- End of function --------------------------------------------------------*/
 
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
 static void sigfpe_handler(int sig_num, siginfo_t *info, void *data)
 {
     switch (sig_num)
@@ -440,7 +440,7 @@ int main(int argc, char *argv[])
     inhandle = NULL;
     outhandle = NULL;
 
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
     fpe_trap_setup();
 #endif
 
diff --git a/tests/v29_tests.c b/tests/v29_tests.c
index 390663f..7a43797 100644
--- a/tests/v29_tests.c
+++ b/tests/v29_tests.c
@@ -58,7 +58,7 @@ display of modem status is maintained.
 #include <string.h>
 #include <sndfile.h>
 #include <signal.h>
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
 #define __USE_GNU
 #include <fenv.h>
 #endif
@@ -257,7 +257,7 @@ static void qam_report(void *user_data, const complexf_t *constel, const complex
 }
 /*- End of function --------------------------------------------------------*/
 
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
 static void sigfpe_handler(int sig_num, siginfo_t *info, void *data)
 {
     switch (sig_num)
@@ -410,7 +410,7 @@ int main(int argc, char *argv[])
     inhandle = NULL;
     outhandle = NULL;
 
-#if defined(HAVE_FENV_H)
+#if defined(HAVE_FEENABLEEXCEPT)
     fpe_trap_setup();
 #endif
 
-- 
2.51.0