From 99771a255f472e1b8465cb67662b70939e9c2d3c Mon Sep 17 00:00:00 2001
From: Angus Gratton <angus@espressif.com>
Date: Mon, 22 May 2017 11:44:41 +1000
Subject: [PATCH] build system: Fix bug where component src subdirs needed
 listing before parent source dirs

Triggered on make 3.81, happens sometimes on Linux and always(?) on macOS. May depend on the order the OS' filesystem
resolves wildcards in.

Includes a revert to the LWIP component to verify this is properly fixed.

See also https://github.com/espressif/esp-idf/issues/632
---
 components/lwip/component.mk |  4 ++--
 make/component_wrapper.mk    | 18 +++++++++++++-----
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/components/lwip/component.mk b/components/lwip/component.mk
index 6473b021a6..204e94fa72 100644
--- a/components/lwip/component.mk
+++ b/components/lwip/component.mk
@@ -14,8 +14,8 @@ endif
 
 COMPONENT_SRCDIRS := \
 	api \
-	apps/sntp apps/ping apps \
-	core/ipv4 core/ipv6 core \
+	apps apps/sntp apps/ping \
+	core core/ipv4 core/ipv6 \
 	$(LWIP_PPP_DIRS) netif \
 	port/freertos port/netif port/debug port
 
diff --git a/make/component_wrapper.mk b/make/component_wrapper.mk
index 87c05479ad..55a92cf421 100644
--- a/make/component_wrapper.mk
+++ b/make/component_wrapper.mk
@@ -154,22 +154,30 @@ endif
 
 # This pattern is generated for each COMPONENT_SRCDIR to compile the files in it.
 define GenerateCompileTargets
-# $(1) - directory containing source files, relative to $(COMPONENT_PATH)
-$(1)/%.o: $$(COMPONENT_PATH)/$(1)/%.c $(COMMON_MAKEFILES) $(COMPONENT_MAKEFILE) | $(1)
+# $(1) - directory containing source files, relative to $(COMPONENT_PATH) - one of $(COMPONENT_SRCDIRS)
+#
+$(1)/%.o: $$(COMPONENT_PATH)/$(1)/%.c $(COMMON_MAKEFILES) $(COMPONENT_MAKEFILE) | $(COMPONENT_SRCDIRS)
 	$$(summary) CC $$@
 	$$(CC) $$(CFLAGS) $$(CPPFLAGS) $$(addprefix -I ,$$(COMPONENT_INCLUDES)) $$(addprefix -I ,$$(COMPONENT_EXTRA_INCLUDES)) -I$(1) -c $$< -o $$@
 
-$(1)/%.o: $$(COMPONENT_PATH)/$(1)/%.cpp $(COMMON_MAKEFILES) $(COMPONENT_MAKEFILE) | $(1)
+$(1)/%.o: $$(COMPONENT_PATH)/$(1)/%.cpp $(COMMON_MAKEFILES) $(COMPONENT_MAKEFILE) | $(COMPONENT_SRCDIRS)
 	$$(summary) CXX $$@
 	$$(CXX) $$(CXXFLAGS) $$(CPPFLAGS) $$(addprefix -I,$$(COMPONENT_INCLUDES)) $$(addprefix -I,$$(COMPONENT_EXTRA_INCLUDES)) -I$(1) -c $$< -o $$@
 
-$(1)/%.o: $$(COMPONENT_PATH)/$(1)/%.S $(COMMON_MAKEFILES) $(COMPONENT_MAKEFILE) | $(1)
+$(1)/%.o: $$(COMPONENT_PATH)/$(1)/%.S $(COMMON_MAKEFILES) $(COMPONENT_MAKEFILE) | $(COMPONENT_SRCDIRS)
 	$$(summary) AS $$@
 	$$(CC) $$(CPPFLAGS) $$(DEBUG_FLAGS) $$(addprefix -I ,$$(COMPONENT_INCLUDES)) $$(addprefix -I ,$$(COMPONENT_EXTRA_INCLUDES)) -I$(1) -c $$< -o $$@
 
 # CWD is build dir, create the build subdirectory if it doesn't exist
+#
+# (NB: Each .o file depends on all relative component build dirs $(COMPONENT_SRCDIRS), rather than just $(1), to work
+# around a behaviour make 3.81 where the first pattern (randomly) seems to be matched rather than the best fit. ie if
+# you have objects a/y.o and a/b/c.o then c.o can be matched with $(1)=a & %=b/c, meaning that subdir 'a/b' needs to be
+# created but wouldn't be created if $(1)=a. Make 4.x doesn't have this problem, it seems to preferentially
+# choose the better match ie $(1)=a/b and %=c )
+#
 $(1):
-	@mkdir -p $(1)
+	mkdir -p $(1)
 endef
 
 # Generate all the compile target patterns