Add support for Linux/riscv64 with musl libc.

* trampoline/trampoline.c (__riscv_flush_icache): New declaration.
* callback/trampoline_r/trampoline.c: Likewise.
* NEWS: Mention the new port.

ChangeLog

@@ -1,3 +1,10 @@
+2024-08-21  Bruno Haible  <[email protected]>
+
+	Add support for Linux/riscv64 with musl libc.
+	* trampoline/trampoline.c (__riscv_flush_icache): New declaration.
+	* callback/trampoline_r/trampoline.c: Likewise.
+	* NEWS: Mention the new port.
+
 2024-08-20  Bruno Haible  <[email protected]>
 
 	Fix support for older Linux versions (regression 2024-08-18).

NEWS

@@ -3,6 +3,7 @@ New in 2.5:
 * Added support for the following platforms:
   (Previously, a build on these platforms failed.)
   - loongarch64: Linux with lp64d ABI.
+  - riscv64: Linux with musl libc.
   - arm: Android.
 * Simplified the environmental requirements (the library no longer allocates
   a temporary file in /tmp) on the following platforms:

callback/trampoline_r/trampoline.c

@@ -224,6 +224,10 @@ kern_return_t mach_vm_remap (vm_map_t target_task,
 #if defined(__mips__) || defined(__mipsn32__) || defined(__mips64__) || defined(__riscv32__) || defined(__riscv64__)
 #ifdef HAVE_SYS_CACHECTL_H /* IRIX, Linux */
 #include <sys/cachectl.h>
+#if defined(__riscv64__) && !defined(__GLIBC__)
+/* musl libc lacks a declaration of this function. */
+extern int __riscv_flush_icache (void *start, void *end, unsigned long flags);
+#endif
 #else
 #ifdef __OpenBSD__
 #include <machine/sysarch.h>

trampoline/trampoline.c

@@ -224,6 +224,10 @@ kern_return_t mach_vm_remap (vm_map_t target_task,
 #if defined(__mips__) || defined(__mipsn32__) || defined(__mips64__) || defined(__riscv32__) || defined(__riscv64__)
 #ifdef HAVE_SYS_CACHECTL_H /* IRIX, Linux */
 #include <sys/cachectl.h>
+#if defined(__riscv64__) && !defined(__GLIBC__)
+/* musl libc lacks a declaration of this function. */
+extern int __riscv_flush_icache (void *start, void *end, unsigned long flags);
+#endif
 #else
 #ifdef __OpenBSD__
 #include <machine/sysarch.h>