From 6812b9d2cde1479cd32237e3743ed4b4d26d7a2b Mon Sep 17 00:00:00 2001
From: Patrick McDermott <patrick.mcdermott@libiquity.com>
Date: Wed, 19 Apr 2023 16:00:29 -0400
Subject: build: Check for all libc functions

---
diff --git a/configure.ac b/configure.ac
index 620a85c..c2a4411 100644
--- a/configure.ac
+++ b/configure.ac
@@ -33,9 +33,21 @@ AC_PROG_CC()
 AM_PROG_CC_C_O()
 test -d "${srcdir}/.git" || CFLAGS="${save_CFLAGS}"
 
-AC_SEARCH_LIBS([log10], [m], [], AC_MSG_ERROR([missing log10]))
-AC_SEARCH_LIBS([ceil],  [m], [], AC_MSG_ERROR([missing ceil]))
-AC_SEARCH_LIBS([lrint], [m], [], AC_MSG_ERROR([missing lrint]))
+funcs_missing=false
+AC_CHECK_FUNCS(
+	[\
+		fclose feof ferror fopen fprintf fputs fread free fwrite \
+		localtime malloc memcmp memcpy memset printf puts snprintf \
+		sprintf strcmp strftime strlen strncpy strtol
+	],
+	[],
+	[funcs_missing=true])
+for func in log10 ceil lrint; do
+	AC_SEARCH_LIBS([${func}], [m], [], [funcs_missing=true])
+done
+if ${funcs_missing}; then
+	AC_MSG_ERROR([required functions are missing])
+fi
 
 PKG_PROG_PKG_CONFIG()
 PKG_CHECK_MODULES([ZLIB], [zlib])
--
cgit v0.9.1