From 15145304ea3f2abff2418adc220c1459190246eb Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Date: Fri, 4 Apr 2025 12:12:10 -0400
Subject: [PATCH] libtracefs: Add make sqlhist_remake to run bison and flex

Because git tends to not maintain timestamps of files, the sqlhist.y and
sqlhist.l can end up having an later timestamp than the files they
produce. This triggers bison and flex to be run and recreate the files
sqlhist.tab.h, sqlhist.tab.c and sqlhist-lex.c.

At best, this causes git to see the differences, at worse, the system may
not even have bison or flex and the build fails.

Add a new make target: make sqlhist_remake

This new target will run the bison and flex portions of the build.
It only needs to be run if the files sqlhist.y or sqlhist.l are modified.

Cc: Oleh Matiusha <omatiush@cisco.com>
Link: https://lore.kernel.org/20250404161504.1671790-2-rostedt@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Upstream-Status: Backport [https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/commit/?id=1514530]

Signed-off-by: Kai Kang <kai.kang@windriver.com>
---
 Makefile      |  3 +++
 src/Makefile  | 14 ++++++++------
 src/sqlhist.l |  2 ++
 src/sqlhist.y |  1 +
 4 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 9f377e9..0fe252b 100644
--- a/Makefile
+++ b/Makefile
@@ -393,6 +393,9 @@ sqlhist: samples/sqlhist
 samples: libtracefs.a force
 	$(Q)$(call descend,$(src)/samples,all)
 
+sqlhist_remake:
+	$(Q)$(call descend,$(src)/src,sqlhist_remake)
+
 clean:
 	$(Q)$(call descend_clean,utest)
 	$(Q)$(call descend_clean,src)
diff --git a/src/Makefile b/src/Makefile
index 90bd88d..eb5a2e7 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -44,18 +44,20 @@ $(LIBTRACEFS_SHARED_SO): $(LIBTRACEFS_SHARED_VERSION)
 libtracefs.so: $(LIBTRACEFS_SHARED_SO)
 
 # bison will create both sqlhist.tab.c and sqlhist.tab.h
-sqlhist.tab.h:
-sqlhist.tab.c: sqlhist.y sqlhist.tab.h
-	bison --debug -v --report-file=bison.report -d -o $@ $<
+sqlhist.tab_gen.h:
+sqlhist.tab_gen.c: sqlhist.y sqlhist.tab.h
+	bison --debug -v --report-file=bison.report -d -o $(subst _gen,,$@) $<
 
-sqlhist-lex.c: sqlhist.l sqlhist.tab.c
-	flex -o $@ $<
+sqlhist-lex_gen.c: sqlhist.l sqlhist.tab.c
+	flex -o $(subst _gen,,$@) $<
 
 $(bdir)/%.o: %.c
 	$(Q)$(call do_fpic_compile)
 
 tracefs-sqlhist.o: sqlhist.tab.h
 
+sqlhist_remake: sqlhist.tab_gen.c sqlhist-lex_gen.c
+
 $(OBJS): | $(bdir)
 
 clean:
@@ -65,4 +67,4 @@ clean:
 
 $(bdir)/tracefs-sqlhist.o tracefs-sqlhist.o: sqlhist.tab.h
 
-.PHONY: $(LIBTRACEFS_SHARED_SO) $(LIBTRACEFS_STATIC)
+.PHONY: $(LIBTRACEFS_SHARED_SO) $(LIBTRACEFS_STATIC) sqlhist.tab_gen.c sqlhist-lex_gen.c
diff --git a/src/sqlhist.l b/src/sqlhist.l
index 4df475a..2a3ca61 100644
--- a/src/sqlhist.l
+++ b/src/sqlhist.l
@@ -1,6 +1,8 @@
 %{
 /* code here */
 
+/* If you change this file, run: make sqlhist_remake */
+
 #include <stdarg.h>
 #include "sqlhist-parse.h"
 
diff --git a/src/sqlhist.y b/src/sqlhist.y
index fade9a4..90039a7 100644
--- a/src/sqlhist.y
+++ b/src/sqlhist.y
@@ -1,4 +1,5 @@
 %{
+/* If you change this file, run: make sqlhist_remake */
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-- 
2.34.1