'make' vs 'make -j1': Tpo files in different places

[Chris Stankevitz]

Hello,

'make' puts my .Tpo in this directory:
.deps/TCExpressionLexer.Tpo

'make -j1' puts my .Tpo in this directory:
.deps/../../../SimLib/SimLib/Expression/TCExpressionLexer.Tpo

Note: Some of my targets are placed in $(srcdir).  These targets are c++ source 
files created by the tool ANTLR.

Question 1: why does 'make' and 'make -j1' place .Tpo files in different 
directories?

Question 2: Is my Makefile.am ok?

Thank you,

Chris

# BEGIN MAKEFILE.AM

# These files are produced by ANTLR.  They must be created before attemping
# to make the application, so they are added to BUILT_SOURCES
BUILT_SOURCES = \
        $(srcdir)/TCExpressionLexer.cpp \
        $(srcdir)/TCExpressionLexer.hpp \
        $(srcdir)/TCExpressionLexerTokenTypes.hpp \
        $(srcdir)/TCExpressionParser.cpp \
        $(srcdir)/TCExpressionParser.hpp \
        $(srcdir)/TCExpressionTreeWalker.cpp \
        $(srcdir)/TCExpressionTreeWalker.hpp

# Clean the auto-generated source files during a clean.  Also include the
# text file that is produced but not used.
CLEANFILES = $(BUILT_SOURCES) $(srcdir)/TCExpressionLexerTokenTypes.txt

# This rule uses the grammar (.g) file to produce the 7 BUILT_SOURCES files
# and the documentation file TCExpressionLexerTokenTypes.txt
$(BUILT_SOURCES) : TCExpression.g
        java antlr.Tool -o $(srcdir) $(srcdir)/TCExpression.g

# These instructions are a "hack" used to instruct make that all of the 
# BUILT_SOURCES are produced when invoking the above rule and they are
# not to be run in parallel
$(srcdir)/TCExpressionLexer.hpp: $(srcdir)/TCExpressionLexer.cpp
$(srcdir)/TCExpressionLexerTokenTypes.hpp: $(srcdir)/TCExpressionLexer.cpp
$(srcdir)/TCExpressionParser.cpp: $(srcdir)/TCExpressionLexer.cpp
$(srcdir)/TCExpressionParser.hpp: $(srcdir)/TCExpressionLexer.cpp
$(srcdir)/TCExpressionTreeWalker.cpp: $(srcdir)/TCExpressionLexer.cpp
$(srcdir)/TCExpressionTreeWalker.hpp: $(srcdir)/TCExpressionLexer.cpp

# Build the expression library by compiling four source files, three of
# which are created by the Java tool ANTLR
lib_LIBRARIES = address@hidden@.a

address@hidden@_a_SOURCES = \
        ExpressionTreeWalker.cpp \ 
        TCExpressionTreeWalker.cpp \
        TCExpressionLexer.cpp \
        TCExpressionParser.cpp