From 5ee2e6348f0b0cb9b57d449410e7e75d47bc81b1 Mon Sep 17 00:00:00 2001
From: YAMAMOTO Takashi <yamamoto@midokura.com>
Date: Wed, 6 Apr 2022 12:24:16 +0900
Subject: [PATCH] Use -fno-builtin for SYMTABOBJ

The code generated by tools/mksymtab.sh uses
```
extern void *var;
```
for ~everything.

After the recent removal of -fno-builtin, [1]
it ends up with warnings:
* -Wbuiltin-requires-header for clang
* -Wbuiltin-declaration-mismatch for gcc

It also generates errors like the following for clang:
```
symtab_apps.c:125:14: error: redefinition of 'strdup' as different kind of symbol
extern void *strdup;
```
I couldn't find a way to disable it.
(it's err_redefinition_different_kind in clang source)

This commit works it around by restoring -fno-builtin
when building SYMTABOBJ.

[1] https://github.com/apache/incubator-nuttx/pull/5476
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index f33a9cffc..e6ddb1633 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,7 @@ $(SYMTABSRC): $(foreach SDIR, $(CONFIGURED_APPS), $(SDIR)_all)
 	$(Q) $(call TESTANDREPLACEFILE, $@.tmp, $@)
 
 $(SYMTABOBJ): %$(OBJEXT): %.c
-	$(call COMPILE, -fno-lto $<, $@)
+	$(call COMPILE, -fno-lto -fno-builtin $<, $@)
 
 $(BIN): $(SYMTABOBJ)
 	$(call ARCHIVE_ADD, $(call CONVERT_PATH,$(BIN)), $^)