#3846 closed defect (fixed)

Build system does not track the dependencies of start.o files

Reported by: Sebastian Huber Owned by: Sebastian Huber
Priority: normal Milestone: 6.1
Component: build Version: 6
Severity: normal Keywords: qualification
Cc: Blocked By:


This defect relates to the new waf based build system.

Most start.o are generated from start.S files which use the C preprocessor. The start.o files are not re-generated if header files (e.g. cpuopts.h, bspopts.h) change. The problem is that the automatic dependency generation via the GCC -MMD flags doesn't work with the current asm rule:

    def asm(self, bld, bic, source, target=None, deps=[], cppflags=[]):
        if target is None:
            target = os.path.splitext(source)[0] + ".o"
            cppflags=cppflags + self.data["cppflags"],
            features="asm c",
            includes=bic.includes + self.data["includes"],
            rule="${CC} ${ASFLAGS} ${CPPFLAGS} ${DEFINES_ST:DEFINES} ${CPPPATH_ST:INCPATHS} -c ${SRC[0]} -o ${TGT}",
            source=[source] + deps,
        return target

Change History (2)

comment:1 Changed on 09/17/20 at 06:58:03 by Sebastian Huber <sebastian.huber@…>

Resolution: fixed
Status: assignedclosed

In 4eea8d4/rtems:

build: Fix dependencies for start and asm files

Add a feature to enforce an explicit target file for assembler sources.
Add a build start file node list and use it as a test program

The fix for #3846 and #4080 needs to be combined, because the fix
for #3846 requires the removal of 'before=cstlib?'. This patch fixes
two issues:

  1. The tracking of start file dependencies.
  1. Reflect that executables depend on the start files.

We need a start.o file in the right path so that the linker can find is
as specified by the linker script, and not for example a start.S.17.o
file in some path. This part is addressed by the "explicit_asm_target"

This build process extension

@feature("cprogram", "cxxprogram")
def process_start_files(self):

if getattr(self, "start_files", False):


addresses 2.

Close #3846.
Close #4080.

comment:2 Changed on 06/23/21 at 07:07:55 by Sebastian Huber

Keywords: qualification added
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