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I'm working on Solaris 11, fully patched. I'm trying to determine if the compiler supports an ISA by dumping preprocessor macros under the ISA.

Make is dying due to a Missing Separator. I'm having trouble finding information about the Missing Separator error when used with GNU make's shell function.

Here is the reduced case. There are no spaces, so its not a space/tab problem like in Make error: missing separator and friends.

$ cat -n GNUmakefile-test
 1  EGREP ?= egrep
 2  SUN_COMPILER := $(shell $(CXX) -V 2>&1 | $(EGREP) -i -c "CC: (Sun|Studio)")
 3
 4  # Begin SunCC
 5  ifeq ($(SUN_COMPILER),1)
 6  $(info "Sun compiler")
 7  $(shell $(CXX) $(CXXFLAGS) -E -xarch=ssse3 -xdumpmacros /dev/null 2>/dev/null)
 8  ifeq ($(.SHELLSTATUS),0)
 9  $(info "SSSE3")
10  SSSE3_FLAG = -xarch=ssse3 -D__SSSE3__=1
11  endif
12  endif
13  # End SunCC
14
15  all:
16          $(info "Do nothing")

The idea above is, SunCC does not provide macros for an ISA, like __AES__ or __SHA__. However, SunCC will error if the ISA is not supported, like -xarch=sha on SunCC 12.4. If I don't get an error, then I know the compiler supports the ISA, like -xarch=aes on SunCC 12.4. If there's an error I can fetch it from .SHELLSTATUS. (SunCC is not like Clang, GCC, Intel ICC, or MSVC in this area).

Here is the result:

$ CXX=/opt/solarisstudio12.4/bin/CC gmake -f GNUmakefile-test
"Sun compiler"
GNUmakefile-test:7: *** missing separator.  Stop.

Where is the missing separator? Or, what is the real error that make is not reporting? Maybe something else?

My apologies for asking this question given how many times its been asked before.

I added tabs in an attempt to appease make. It produced the same error.

$ cat -n GNUmakefile-test
 1  EGREP ?= egrep
 2  SUN_COMPILER := $(shell $(CXX) -V 2>&1 | $(EGREP) -i -c "CC: (Sun|Studio)")
 3
 4  # Begin SunCC
 5  ifeq ($(SUN_COMPILER),1)
 6       $(info "Sun compiler")
 7       $(shell $(CXX) $(CXXFLAGS) -E -xarch=ssse3 -xdumpmacros /dev/null 2>/dev/null)
 8       ifeq ($(.SHELLSTATUS),0)
 9            $(info "SSSE3")
10            SSSE3_FLAG = -xarch=ssse3 -D__SSSE3__=1
11       endif
12  endif
13  # End SunCC
14
15  all:
16       $(info "Do nothing")
jww
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  • The [documentation of GNU make shell functions](https://www.gnu.org/software/make/manual/html_node/Shell-Function.html) is pretty sparse, but I'd try eliminating the `2>` redirect and see if that's causing the problem. – Andrew Henle Aug 24 '17 at 17:35

2 Answers2

7

The way the shell function works (as discussed in the manual) is that it runs the command, and then it expands to the output of the command. That's why, when you see:

SUN_COMPILER := $(shell $(CXX) -V 2>&1 | $(EGREP) -i -c "CC: (Sun|Studio)")

the variable SUN_COMPILER is set to the output of that shell command.

So when you write this:

$(shell $(CXX) $(CXXFLAGS) -E -xarch=ssse3 -xdumpmacros /dev/null 2>/dev/null)

the command is run, then the output is substituted. After that, make tries to parse the results as make syntax. But the output of that command is clearly NOT make syntax, so you get this error.

If you don't care about the output and only care about the exit code, you need to either throw away the output:

$(shell $(CXX) $(CXXFLAGS) -E -xarch=ssse3 -xdumpmacros /dev/null >/dev/null 2>&1)

or else assign it to a dummy variable:

_x := $(shell $(CXX) $(CXXFLAGS) -E -xarch=ssse3 -xdumpmacros /dev/null 2>/dev/null)

so that make assigns the result to a variable rather than thinking it's make syntax.

MadScientist
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  • Thanks @MadScientist. Just to be clear, I visited the manual before asking the question. The manual does not state those requirements. It does say I can use `.SHELLSTATUS`, however. (And what's up with the useless error message? That's probably been broken for years). – jww Aug 24 '17 at 18:13
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    *The way the `shell` function works (as discussed in the manual) ...* It's not exactly made clear in the documentation that the expanded result might very well be executed as a command. [The documentation here](https://www.gnu.org/software/make/manual/html_node/Shell-Function.html) simply states "The `shell` function performs the same function that backquotes (‘`’) perform in most shells: it does command expansion. ..." – Andrew Henle Aug 24 '17 at 18:57
  • I'm not sure what you mean by "the useless error message". That's the error message make gives when it can't understand the line of the makefile. Because of makefile's free-form syntax there's not much more make can say than that. The manual does say exactly what I said: the `shell` function _evaluates to the output of the command_. As with any function, how the result is interpreted depends on where in the makefile the reference appears. It's true that read by itself, without understanding the rest of this chapter on how GNU make functions work, this may not be entirely clear. – MadScientist Aug 25 '17 at 01:24
0

We decided to avoid .SHELLSTATUS since it seems to have some problems. We fell back to grep and the string "illegal value ignored".

ifeq ($(SUN_COMPILER),1)
  COUNT := $(shell $(CXX) $(CXXFLAGS) -E -xarch=ssse3 -xdumpmacros /dev/null 2>&1 | $(EGREP) -i -c "illegal value ignored")
  ifeq ($(COUNT),0)
    SSSE3_FLAG = -xarch=ssse3 -D__SSSE3__=1
    ARIA_FLAG = -xarch=ssse3 -D__SSSE3__=1
  endif
  COUNT := $(shell $(CXX) $(CXXFLAGS) -E -xarch=sse4_2 -xdumpmacros /dev/null 2>&1 | $(EGREP) -i -c "illegal value ignored")
  ifeq ($(COUNT),0)
    BLAKE2_FLAG = -xarch=sse4_2 -D__SSE4_2__=1
    CRC_FLAG = -xarch=sse4_2 -D__SSE4_2__=1
  endif
  COUNT := $(shell $(CXX) $(CXXFLAGS) -E -xarch=aes -xdumpmacros /dev/null 2>&1 | $(EGREP) -i -c "illegal value ignored")
  ifeq ($(COUNT),0)
    GCM_FLAG = -xarch=aes -D__PCLMUL__=1
    AES_FLAG = -xarch=aes -D__AES__=1
  endif
  COUNT := $(shell $(CXX) $(CXXFLAGS) -E -xarch=sha -xdumpmacros /dev/null 2>&1 | $(EGREP) -i -c "illegal value ignored")
  ifeq ($(COUNT),0)
    SHA_FLAG = -xarch=sha -D__SHA__=1
  endif
endif
# End SunCC

We are not sure about -xarch=sha. At the moment we are trying to figure out what is needed.

jww
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