htcp

commit 45e11bae6b983236fe35d9dd32f23a8474160404
parent f65270790ced5854725562d7b42dfc86a2d0b329
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Mon, 25 Sep 2023 15:56:49 +0200

Generate position-independent executables

Use the -fPIE compiler option when building executables and link them
with the -pie option and all other compiler flags used during
compilation. This follows the recommendation of the GCC manual for the
-pie option: "For predictable results, you must also specify the same
set of options used for compilation".

CFLAGS are now differentiated when compiling object files for a shared
object or for an executable. The former use the -fPIC flag, while the
latter require -fPIE. Similarly, the link editor flags are also
distinct. We therefore define 4 macros as follows: CFLAGS_SO,
CFLAGS_EXE, LDFLAGS_SO and LDFLAGS_EXE.

Diffstat:
M
Makefile
 | 
19
++++++++++---------
M
config.mk
 | 
7
++++---

2 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/Makefile b/Makefile
@@ -47,7 +47,7 @@ build_program: .config src/les2htcp.d build_library
 $(DEP) $(OBJ): config.mk
 
 $(LIBNAME_SHARED): $(OBJ)
-	$(CC) $(CFLAGS) $(RSYS_CFLAGS) -o $@ $(OBJ) $(LDFLAGS) $(SOFLAGS) $(RSYS_LIBS)
+	$(CC) $(CFLAGS_SO) $(RSYS_CFLAGS) -o $@ $(OBJ) $(LDFLAGS_SO) $(RSYS_LIBS)
 
 $(LIBNAME_STATIC): $(OBJ)
 	$(AR) -rc $@ $?
@@ -63,7 +63,8 @@ src/les2htcp.h: src/les2htcp.h.in
 	    src/les2htcp.h.in > $@
 
 les2htcp: src/les2htcp.o
-	$(CC) -o $@ src/les2htcp.o $(LDFLAGS) $(RSYS_LIBS) $(NETCDF_LIBS) -lm
+	$(CC) $(CFLAGS_EXE) $(RSYS_CFLAGS) $(NETCDF_CFLAGS) \
+	-o $@ src/les2htcp.o $(LDFLAGS_EXE) $(RSYS_LIBS) $(NETCDF_LIBS) -lm
 
 .config: config.mk
 	@if ! $(PKG_CONFIG) --atleast-version $(RSYS_VERSION) rsys; then \
@@ -74,17 +75,17 @@ les2htcp: src/les2htcp.o
 
 .SUFFIXES: .c .d .o
 .c.d:
-	@$(CC) $(CFLAGS) $(RSYS_CFLAGS) -MM -MT "$(@:.d=.o) $@" $< -MF $@
+	@$(CC) $(CFLAGS_SO) $(RSYS_CFLAGS) -MM -MT "$(@:.d=.o) $@" $< -MF $@
 
 .c.o:
-	$(CC) $(CFLAGS) $(RSYS_CFLAGS) -DHTCP_SHARED_BUILD -c $< -o $@
+	$(CC) $(CFLAGS_SO) $(RSYS_CFLAGS) -DHTCP_SHARED_BUILD -c $< -o $@
 
 src/les2htcp.d: src/les2htcp.c
-	@$(CC) $(CFLAGS) $(RSYS_CFLAGS) $(NETCDF_CFLAGS) -MM -MT "$(@:.d=.o) $@" \
+	@$(CC) $(CFLAGS_EXE) $(RSYS_CFLAGS) $(NETCDF_CFLAGS) -MM -MT "$(@:.d=.o) $@" \
 	src/les2htcp.c -MF $@
 
 src/les2htcp.o: src/les2htcp.c
-	$(CC) $(CFLAGS) $(RSYS_CFLAGS) $(NETCDF_CFLAGS) -c src/les2htcp.c -o $@
+	$(CC) $(CFLAGS_EXE) $(RSYS_CFLAGS) $(NETCDF_CFLAGS) -c src/les2htcp.c -o $@
 
 ################################################################################
 # Installation
@@ -168,14 +169,14 @@ clean_test:
 	$(SHELL) make.sh clean_test $(TEST_SRC)
 
 $(TEST_DEP): config.mk htcp-local.pc
-	@$(CC) $(CFLAGS) $(RSYS_CFLAGS) $(HTCP_CFLAGS) \
+	@$(CC) $(CFLAGS_EXE) $(RSYS_CFLAGS) $(HTCP_CFLAGS) \
 	-MM -MT "$(@:.d=.o) $@" $(@:.d=.c) -MF $@
 
 $(TEST_OBJ): config.mk htcp-local.pc
-	$(CC) $(CFLAGS) $(RSYS_CFLAGS) $(HTCP_CFLAGS) -c $(@:.o=.c) -o $@
+	$(CC) $(CFLAGS_EXE) $(RSYS_CFLAGS) $(HTCP_CFLAGS) -c $(@:.o=.c) -o $@
 
 test_htcp \
 test_htcp_load \
 test_htcp_load_from_file \
 : config.mk htcp-local.pc
-	$(CC) -o $@ src/$@.o $(RSYS_LIBS) $(HTCP_LIBS) -lm
+	$(CC) $(CFLAGS_EXE) -o $@ src/$@.o $(LDFLAGS_EXE) $(RSYS_LIBS) $(HTCP_LIBS) -lm
diff --git a/config.mk b/config.mk
@@ -48,20 +48,21 @@ WFLAGS =\
 CFLAGS_COMMON =\
  -std=c89\
  -pedantic\
- -fPIC\
  -fvisibility=hidden\
  -fstrict-aliasing\
  $(WFLAGS)
 
 CFLAGS_RELEASE = -O2 -DNDEBUG $(CFLAGS_COMMON)
 CFLAGS_DEBUG = -g $(CFLAGS_COMMON)
-CFLAGS = $(CFLAGS_$(BUILD_TYPE))
+CFLAGS_SO = $(CFLAGS_$(BUILD_TYPE)) -fPIC
+CFLAGS_EXE = $(CFLAGS_$(BUILD_TYPE)) -fPIE
 
 ################################################################################
 # Linker options
 ################################################################################
-SOFLAGS = -shared -Wl,--no-undefined
 
 LDFLAGS_DEBUG =
 LDFLAGS_RELEASE = -s
 LDFLAGS = $(LDFLAGS_$(BUILD_TYPE))
+LDFLAGS_SO = $(LDFLAGS_$(BUILD_TYPE)) -shared -Wl,--no-undefined
+LDFLAGS_EXE = $(LDFLAGS_$(BUILD_TYPE)) -pie