git: 92f73068bf69 - stable/13 - Makefile.inc1: Make sure sub-makes see MK_CLANG_BOOTSTRAP=no when XCC is a path

[Jessica Clarke]

The branch stable/13 has been updated by jrtc27:

URL: https://cgit.FreeBSD.org/src/commit/?id=92f73068bf695960c884a44bf31f972305f947bf

commit 92f73068bf695960c884a44bf31f972305f947bf
Author:     Jessica Clarke <jrtc27 at FreeBSD.org>
AuthorDate: 2021-08-24 13:55:31 +0000
Commit:     Jessica Clarke <jrtc27 at FreeBSD.org>
CommitDate: 2021-09-07 12:08:18 +0000

    Makefile.inc1: Make sure sub-makes see MK_CLANG_BOOTSTRAP=no when XCC is a path
    
    Currently we override MK_CLANG_BOOTSTRAP to no so we don't build a
    bootstrap compiler, but subdirectories don't see that and so the hack in
    bsd.sys.mk to prefer our includes over Clang's resource dir for external
    toolchains is not enabled unless you use -DWITHOUT_CLANG_BOOTSTRAP
    explicitly on top of XCC (which tools/build/make.py does not do),
    causing duplicate definition errors when building rtld-elf due to the
    use of -ffreestanding (Clang's stdint.h will use the system one when
    hosted, but its own when freestanding, and only has glibc's preprocessor
    guards, not FreeBSD's).
    
    This broke when dropping CLANG_BOOTSTRAP from BROKEN_OPTIONS.
    
    Fixes:          31ba4ce8898f ("Allow bootstrapping llvm-tblgen on macOS and Linux")
    MFC after:      1 week
    Reviewed by:    imp, arichardson
    Differential Revision:  https://reviews.freebsd.org/D31529
    
    (cherry picked from commit ab3a18095faebe306989f25288c44968f4144063)
---
 Makefile.inc1 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Makefile.inc1 b/Makefile.inc1
index 3429d8312d3e..81567af5897b 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -94,6 +94,9 @@ X${COMPILER}?=	${${COMPILER}}
 # a cross compiler.
 .if ${XCC:N${CCACHE_BIN}:M/*}
 MK_CLANG_BOOTSTRAP=	no
+# Make sure sub-makes see the option as disabled so the hack in bsd.sys.mk to
+# work around incompatible headers in Clang's resource directory is enabled.
+.MAKEOVERRIDES+=	MK_CLANG_BOOTSTRAP
 .endif
 
 # Pull in compiler metadata from buildworld/toolchain if possible to avoid