[Makefiles] Use custom CC in ocamlopt only when configure flag is set

Summary: Introduce `--enable-ocamlopt-custom-cc` configure flag (disabled by default). Normally it doesn't have to be set. However, when cross-compiling infer itself for another platform it may have to be set.

Reviewed By: jberdine

Differential Revision: D3995032

fbshipit-source-id: ce2fd72

Makefile.config.in

@@ -20,6 +20,7 @@ CLANG_PREFIX = @CLANG_PREFIX@
 CPP = @CPP@
 CXX = @CXX@
 CXXFLAGS = @CXXFLAGS@
+ENABLE_OCAMLOPT_CUSTOM_CC = @ENABLE_OCAMLOPT_CUSTOM_CC@
 ENABLE_OCAML_ANNOT = @ENABLE_OCAML_ANNOT@
 ENABLE_OCAML_BINANNOT = @ENABLE_OCAML_BINANNOT@
 exec_prefix = @exec_prefix@

configure.ac

@@ -102,6 +102,12 @@ AS_IF([test "x$enable_c_analyzers" = "xyes"], [
     AC_CHECK_TOOL([CMAKE], [cmake], [no])
     AC_ASSERT_PROG([cmake], [$CMAKE])
   ])
+  AC_ARG_ENABLE(ocamlopt-custom-cc,
+    AS_HELP_STRING([--enable-ocamlopt-custom-cc], [use CC in ocamlopt invocations]),
+    ,
+    enable_ocamlopt_custom_cc=no)
+  ENABLE_OCAMLOPT_CUSTOM_CC=$enable_ocamlopt_custom_cc
+  AC_SUBST([ENABLE_OCAMLOPT_CUSTOM_CC])
 ])
 # end if($enable_c_analyzers)
 

infer/src/Makefile

@@ -22,8 +22,6 @@ OCAML_FATAL_WARNINGS = +5+6+8+10+11+12+18+19+20+23+26+29+27+32+33+34+35+37+38+39
 
 OCAMLBUILD_OPTIONS = \
                      -r \
-                     -lflags -cc,$(CC) \
-                     -cflags -cc,$(CC) \
                      -cflags -g -lflags -g \
                      -cflags -short-paths \
                      -cflags -safe-string \
@@ -42,6 +40,10 @@ ifeq ($(ENABLE_OCAML_BINANNOT),yes)
 OCAMLBUILD_OPTIONS += -cflags -bin-annot
 endif
 
+ifeq ($(ENABLE_OCAMLOPT_CUSTOM_CC),yes)
+OCAMLBUILD_OPTIONS += -lflags -cc,$(CC) -cflags -cc,$(CC)
+endif
+
 ifneq (,$(findstring s,$(MAKEFLAGS)))
 OCAMLBUILD_OPTIONS += -quiet
 endif