libubacktrace: fix backtrace for statically linked application

libgcc_s.so's unwinder could not access unwind tables of statically
linked binaries, so we really want to use _Unwind_* stuff from
libgcc_eh.a.
It required to build backtrace.c differentiating between shared and
static case.

Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

libubacktrace/Makefile.in

@@ -25,11 +25,13 @@ libubacktrace_ARCH_OUT:=$(libubacktrace_OUT)/$(TARGET_ARCH)
 -include $(libubacktrace_ARCH_DIR)/Makefile.arch
 
 libubacktrace_SRC-y :=
-libubacktrace_SRC-$(UCLIBC_HAS_BACKTRACE) := backtrace.c backtracesyms.c backtracesymsfd.c
+libubacktrace_SRC-$(UCLIBC_HAS_BACKTRACE) := backtracesyms.c backtracesymsfd.c
+libubacktrace_SRC_SHARED-$(UCLIBC_HAS_BACKTRACE) := backtrace.c
 
 # remove generic sources, if arch specific version is present
 ifneq ($(strip $(libubacktrace_ARCH_SRC-y)),)
 libubacktrace_SRC-y := $(filter-out $(notdir $(libubacktrace_ARCH_SRC-y)),$(libubacktrace_SRC-y))
+libubacktrace_SRC_SHARED-y := $(filter-out $(notdir $(libubacktrace_ARCH_SRC-y)),$(libubacktrace_SRC_SHARED-y))
 endif
 
 # -fasynchronous-unwind-tables is required for backtrace to work using dwarf2
@@ -43,12 +45,19 @@ endif
 libubacktrace_SRCS := $(patsubst %.c,$(libubacktrace_DIR)/%.c,$(libubacktrace_SRC-y))
 libubacktrace_OBJS := $(patsubst $(libubacktrace_DIR)/%.c,$(libubacktrace_OUT)/%.o,$(libubacktrace_SRCS))
 
+libubacktrace_SHARED_SRCS := $(patsubst %.c,$(libubacktrace_DIR)/%.c,$(libubacktrace_SHARED_SRC-y))
+libubacktrace_SHARED_OBJS := $(patsubst $(libubacktrace_DIR)/%.c,$(libubacktrace_OUT)/%.s,$(libubacktrace_SHARED_SRCS))
+
+libubacktrace-shared-y	:= $(libubacktrace_SHARED_OBJS:.os=.oS)
+libubacktrace-static-y	:= $(libubacktrace_SHARED_OBJS)
+
 ifeq ($(DOPIC),y)
-libubacktrace-a-y += $(libubacktrace_OBJS:.o=.os)
+libubacktrace-a-y += $(libubacktrace_OBJS:.o=.os) $(libubacktrace-static-y:.o=.os)
 else
-libubacktrace-a-y += $(libubacktrace_OBJS)
+libubacktrace-a-y += $(libubacktrace_OBJS) $(libubacktrace-static-y)
 endif
-libubacktrace-so-y += $(libubacktrace_OBJS:.o=.os)
+libubacktrace-so-y += $(libubacktrace_OBJS:.o=.os) $(libubacktrace-shared-y)
+
 
 lib-a-$(UCLIBC_HAS_BACKTRACE) += $(top_builddir)lib/libubacktrace.a
 lib-so-$(UCLIBC_HAS_BACKTRACE) += $(top_builddir)lib/libubacktrace.so
@@ -56,11 +65,7 @@ lib-so-$(UCLIBC_HAS_BACKTRACE) += $(top_builddir)lib/libubacktrace.so
 objclean-y += CLEAN_libubacktrace
 
 ifeq ($(DOMULTI),n)
-ifeq ($(DOPIC),y)
-$(top_builddir)lib/libubacktrace.so: $(top_builddir)lib/libubacktrace.a $(libdl.depend)
-else
 $(top_builddir)lib/libubacktrace.so: $(libubacktrace_OUT)/libubacktrace_so.a $(libdl.depend)
-endif
 	$(call link.so,$(libubacktrace_FULL_NAME),$(ABI_VERSION))
 else
 $(top_builddir)lib/libubacktrace.so: $(libubacktrace_OUT)/libubacktrace.oS | $(libdl.depend)
@@ -71,7 +76,7 @@ $(libubacktrace_OUT)/libubacktrace_so.a: $(libubacktrace-so-y)
 	$(Q)$(RM) $@
 	$(do_ar)
 
-$(libubacktrace_OUT)/libubacktrace.oS: $(libubacktrace_SRCS) $(libubacktrace_ARCH_SRCS)
+$(libubacktrace_OUT)/libubacktrace.oS: $(libubacktrace_SRCS) $(libubacktrace_ARCH_SRCS) $(libubacktrace_SHARED_SRCS)
 	$(Q)$(RM) $@
 	$(compile-m)
 

libubacktrace/arm/Makefile.arch

@@ -14,4 +14,4 @@ libubacktrace-a-y+=$(libubacktrace_ARCH_OBJS:.o=.os)
 else
 libubacktrace-a-y+=$(libubacktrace_ARCH_OBJS)
 endif
-libubacktrace-so-y+=$(libubacktrace_ARCH_OBJS:.o=.os)
+libubacktrace-so-y+=$(libubacktrace_ARCH_OBJS:.o=.oS)

libubacktrace/arm/backtrace.c

@@ -26,6 +26,7 @@ struct trace_arg
   int cnt, size;
 };
 
+#ifdef SHARED
 static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
 static _Unwind_VRS_Result (*unwind_vrs_get) (_Unwind_Context *,
 					     _Unwind_VRS_RegClass,
@@ -43,6 +44,10 @@ static void backtrace_init (void)
 		abort();
 	}
 }
+#else
+# define unwind_backtrace _Unwind_Backtrace
+# define unwind_vrs_get _Unwind_VRS_Get
+#endif
 /* This function is identical to "_Unwind_GetGR", except that it uses
    "unwind_vrs_get" instead of "_Unwind_VRS_Get".  */
 static inline _Unwind_Word
@@ -81,8 +86,10 @@ int backtrace (void **array, int size)
 {
 	struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
 
+#ifdef SHARED
 	if (unwind_backtrace == NULL)
 		backtrace_init();
+#endif
 
 	if (size >= 1)
 		unwind_backtrace (backtrace_helper, &arg);

libubacktrace/backtrace.c

@@ -34,6 +34,7 @@ struct trace_arg
   int cnt, size;
 };
 
+#ifdef SHARED
 static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
 static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
 
@@ -48,6 +49,10 @@ static void backtrace_init (void)
 		abort();
 	}
 }
+#else
+# define unwind_backtrace _Unwind_Backtrace
+# define unwind_getip _Unwind_GetIP
+#endif
 
 static _Unwind_Reason_Code
 backtrace_helper (struct _Unwind_Context *ctx, void *a)
@@ -72,8 +77,10 @@ int backtrace (void **array, int size)
 {
 	struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
 
+#ifdef SHARED
 	if (unwind_backtrace == NULL)
 		backtrace_init();
+#endif
 
 	if (size >= 1)
 		unwind_backtrace (backtrace_helper, &arg);