From b6cd577cf6ea1de28092a7abe58613c66debd412 Mon Sep 17 00:00:00 2001
From: Jeff Epler <jepler@gmail.com>
Date: Thu, 14 Aug 2025 10:22:11 -0500
Subject: [PATCH] py/mkrules.mk: Force ".pp" files to always rebuild.

These files are only built on demand for developers, and it is a quick
process.

Without FORCE, a sequence like this would leave the developer with an
outdated `main.pp` to inspect:

    make build-standard/main.pp
    touch input.h
    make build-standard/main.pp # Rebuilds now, wouldn't have before

Signed-off-by: Jeff Epler <jepler@gmail.com>
---
 py/mkrules.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/py/mkrules.mk b/py/mkrules.mk
index 3120066fd4..6993a13a4f 100644
--- a/py/mkrules.mk
+++ b/py/mkrules.mk
@@ -104,7 +104,7 @@ vpath %.cpp . $(TOP) $(USER_C_MODULES)
 $(BUILD)/%.o: %.cpp
 	$(call compile_cxx)
 
-$(BUILD)/%.pp: %.c
+$(BUILD)/%.pp: %.c FORCE
 	$(ECHO) "PreProcess $<"
 	$(Q)$(CPP) $(CFLAGS) -Wp,-C,-dD,-dI -o $@ $<