Shell if statement executed from Makefile always evaluates to false

Question

I need to add shell if-else statement to my Makefile, but the if expression always evaluates to false. For example the next code:

if [1 -eq 1]; then echo "yes"; else echo "no"

prints "no"

The only code that evaluated to true was:

if true; then echo "yes"; else echo "no"

Why all expressions in the code (except for "true") evaluates to false? :( I would really appreciate any help

** Please note - the statements work correctly when run from Shell

The code snippet from the original Makefile:

SIMULATION_RUN_CMD =  rm -rf $(TEST_DIR)/* && mkdir -p $(TEST_DIR) && cd $(TEST_DIR) && (cp -rf $(VIVADO_PROJ)/$(PROJECT)/export_for_sim/$(SIMULATOR)/{*.mem,.mif,design.dat,nocattrs.dat,cpm_data_sim.cdo} $(TEST_DIR) || true) && \
                                        ln -sf $(TEST_DIR)/simulation.log $(RUN_DIR)/simulation.log && \
                                        (timeout $(SIM_TIMEOUT) ${SIM_DIR}/simv +UVM_TESTNAME=$(UVM_TESTNAME) $(SIM_FLAGS) -l $(TEST_DIR)/simulation.log -do $(DO_FILE) ; \
                                        if [1 -eq 1]; then echo "if statement yes " >> $(TEST_DIR)/simulation.log; else echo "if statement no " >> $(TEST_DIR)/simulation.log; fi \
                                         || true) && \
                                        $(MODEL_POST_SIM_ACIONS)


$(SIMULATION_RUN_TAR):
    @echo -e "Make Command: $(SIMULATION_RUN_CMD)" $(PRINT_OUTPUT)
    ($(SIMULATION_RUN_CMD)) $(PRINT_OUTPUT)

Answer 1

First, you have a syntax error in your command. If you type that exactly into bash you'll get an error:

[[1: command not found

You need spaces after the [[ and before the ]] tokens:

if [[ 1 -eq 1 ]]; then echo "yes"; else echo "no"

Second, the reason it doesn't work when run from make is that make doesn't invoke bash. Make invokes the POSIX standard shell /bin/sh. If you do this you'll see the same behavior you get with make:

$ /bin/sh -c 'if [[ 1 -eq 1 ]]; then echo yes; else echo no; fi'
/bin/sh: 1: [[: not found
no

The [[ operator is a bash-specific feature. If you want to write this using POSIX features you should use:

$ /bin/sh -c 'if [ 1 -eq 1 ]; then echo yes; else echo no; fi'
yes

If you really want make to invoke bash as its shell instead of sh, add this to your makefile:

SHELL := /bin/bash

Of course then your makefile will not work on any system that doesn't have /bin/bash available.

ETA

After seeing the very much more complicated, but still not complete, code you added, I will say the following:

As I said above, you have an error in your script. if [1 -eq 1] is completely illegal. You must have spaces after [ and before ]. Again, if you run this yourself at the shell prompt you will get the same failure. It has nothing to do with make.

Because of this error, the if-statement will ALWAYS fail and so this will ALWAYS run the "else" command and print "no".

You say you don't see any error message. I can't explain that, except that you run this recipe this way:

($(SIMULATION_RUN_CMD)) $(PRINT_OUTPUT)

You don't tell use what the value of the PRINT_OUTPUT variable is, so I can only assume that it throws away stderr into the bit-bucket (or possibly, both stdout and stderr). If you didn't do that, so you could see the output, you'd see the error message being printed. Or maybe that redirects to a log file in which case, you can look there for the message.