Enable gcc-14 build rv_histogram on macOS/arm64

Error:
Undefined symbols for architecture arm64:
  "_ebreak_handler", referenced from:
      lC0 in riscv.o
  "_ecall_handler", referenced from:
      lC0 in riscv.o
  "_log_impl", referenced from:
      _rv_create in riscv.o
      _rv_create in riscv.o
      _rv_create in riscv.o
      _rv_profile in riscv.o
      _rv_profile in riscv.o
      _rv_run in riscv.o
  "_log_level_string", referenced from:
      _rv_create in riscv.o
  "_log_set_level", referenced from:
      _rv_create in riscv.o
  "_log_set_stdout_stream", referenced from:
      _rv_remap_stdstream in riscv.o
  "_memcpy_handler", referenced from:
      lC0 in riscv.o
  "_memory_delete", referenced from:
      _rv_delete in riscv.o
      _rv_create in riscv.o
  "_memory_ifetch", referenced from:
      _on_mem_ifetch in riscv.o
  "_memory_new", referenced from:
      _rv_create in riscv.o
  "_memory_read_b", referenced from:
      _on_mem_read_b in riscv.o
  "_memory_read_s", referenced from:
      _on_mem_read_s in riscv.o
  "_memory_read_w", referenced from:
      _on_mem_read_w in riscv.o
  "_memory_write_b", referenced from:
      _on_mem_write_b in riscv.o
  "_memory_write_s", referenced from:
      _on_mem_write_s in riscv.o
  "_memory_write_w", referenced from:
      _on_mem_write_w in riscv.o
  "_memset_handler", referenced from:
      lC0 in riscv.o
  "_rv", referenced from:
      _rv_async_block_clear in riscv.o
  "_rv_step", referenced from:
      _rv_run in riscv.o
      _rv_run in riscv.o
  "_trap_handler", referenced from:
      lC0 in riscv.o
ld: symbol(s) not found for architecture arm64
collect2: error: ld returned 1 exit status
make: *** [build/rv_histogram] Error 1

Add emulate.o, syscall.o, syscall_sdl.o, io.o, and log.o objects and
conditional build rv_async_block_clear() fixes the error and passes the
build.

Author: ChinYikMing

mk/tools.mk

@@ -1,6 +1,10 @@
 HIST_BIN := $(OUT)/rv_histogram
 
-# FIXME: riscv.o and map.o are dependencies of 'elf.o', not 'rv_histogram'.
+# On macOS, gcc-14 requires linking symbols from emulate.o, syscall.o, syscall_sdl.o, io.o, and log.o.
+# However, these symbols are not actually used in rv_histogram, they are only needed to pass the build.
+#
+# riscv.o and map.o are dependencies of 'elf.o', not 'rv_histogram'. But, they are also needed to pass
+# the build.
 HIST_OBJS := \
 	riscv.o \
 	utils.o \
@@ -9,6 +13,11 @@ HIST_OBJS := \
 	decode.o \
 	mpool.o \
 	utils.o \
+	emulate.o \
+	syscall.o \
+	syscall_sdl.o \
+	io.o \
+	log.o \
 	rv_histogram.o
 
 HIST_OBJS := $(addprefix $(OUT)/, $(HIST_OBJS))

src/riscv.c

@@ -357,6 +357,7 @@ static void capture_keyboard_input()
 
 #endif
 
+#if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
 /*
  *
  * atexit() registers void (*)(void) callbacks, so no parameters can be passed.
@@ -375,6 +376,7 @@ static void rv_async_block_clear()
     return;
 #endif /* !RV32_HAS(JIT) */
 }
+#endif
 
 riscv_t *rv_create(riscv_user_t rv_attr)
 {
@@ -383,8 +385,10 @@ riscv_t *rv_create(riscv_user_t rv_attr)
     riscv_t *rv = calloc(1, sizeof(riscv_t));
     assert(rv);
 
+#if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
     /* register cleaning callback for CTRL+a+x exit */
     atexit(rv_async_block_clear);
+#endif
 
     /* copy over the attr */
     rv->data = rv_attr;