From f4e120417651d8ca21fa0cdbe802dee57aa5e1b1 Mon Sep 17 00:00:00 2001
From: David Allsopp <david.allsopp@metastack.com>
Date: Wed, 12 May 2021 16:43:12 +0100
Subject: Refactor MKEXE and introduce MKEXE_VIA_CC

Tidies up the flexlink aspects. Previously, it was viewed as MKEXE and a
special case needed in flexlink bootstrap to build the runtime without
using flexlink.

This commit moves the flags decisions into configure where they belong
and now exposes two versions of a command which links executables. MKEXE
_may_ link using a C compiler but may be a direct call to a wrapper for
a linker (i.e. flexlink). MKEXE_VIA_CC _always_ creates an executable by
calling the C compiler.

Rather than deriving the entire mkexe command line, configure now
determines what the _command_ will be (i.e. `$(CC)` or
`$(FLEXLINK_CMD)`) and the flags which get passed to that (and their
`-link` prefixes, if necessary) are computed _at the end of the
process_ which hopefully simplifies the number of special cases which
have to be considered during configuration.
---
 utils/Makefile   |  7 +++++--
 utils/config.mlp | 26 +++++++++++++-------------
 2 files changed, 18 insertions(+), 15 deletions(-)

(limited to 'utils')

diff --git a/utils/Makefile b/utils/Makefile
index 9c26fddba1..3afb6468ce 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -34,8 +34,10 @@ SUBST_QUOTE2=\
   -e 's!%%$1%%!$(if $2,$(call SED_ESCAPE,"$(call OCAML_ESCAPE,$2)"))!'
 SUBST_QUOTE=$(call SUBST_QUOTE2,$1,$($1))
 
-FLEXLINK_LDFLAGS=$(if $(OC_LDFLAGS), -link "$(OC_LDFLAGS)")
-FLEXLINK_DLL_LDFLAGS=$(if $(OC_DLL_LDFLAGS), -link "$(OC_DLL_LDFLAGS)")
+prefix_and_quote = $(if $(1), $(2)$(if $(word 2,$(1)),"$(1)",$(1)))
+
+FLEXLINK_LDFLAGS = $(call prefix_and_quote,$(OC_LDFLAGS),-link $(EMPTY))
+FLEXLINK_DLL_LDFLAGS = $(call prefix_and_quote,$(OC_DLL_LDFLAGS),-link $(EMPTY))
 
 config_main.ml: config.mlp $(ROOTDIR)/Makefile.config Makefile config.common.ml
 	sed $(call SUBST,AFL_INSTRUMENT) \
@@ -57,6 +59,7 @@ config_main.ml: config.mlp $(ROOTDIR)/Makefile.config Makefile config.common.ml
 	    $(call SUBST,WITH_CMM_INVARIANTS) \
 	    $(call SUBST_STRING,FLEXLINK_FLAGS) \
 	    $(call SUBST_QUOTE,FLEXDLL_DIR) \
+	    $(call SUBST_STRING,FLEXDLL_CHAIN) \
 	    $(call SUBST,HOST) \
 	    $(call SUBST_STRING,BINDIR) \
 	    $(call SUBST_STRING,LIBDIR) \
diff --git a/utils/config.mlp b/utils/config.mlp
index 021d28579b..4b6343a9d9 100644
--- a/utils/config.mlp
+++ b/utils/config.mlp
@@ -47,21 +47,21 @@ let mksharedlibrpath = "%%MKSHAREDLIBRPATH%%"
 let ar = "%%ARCMD%%"
 let supports_shared_libraries = %%SUPPORTS_SHARED_LIBRARIES%%
 let mkdll, mkexe, mkmaindll =
-  (* @@DRA Cygwin - but only if shared libraries are enabled, which we
-     should be able to detect? *)
   if Sys.win32 || Sys.cygwin && supports_shared_libraries then
-    try
+    let flexlink =
       let flexlink =
-        let flexlink = Sys.getenv "OCAML_FLEXLINK" in
-        let f i =
-          let c = flexlink.[i] in
-          if c = '/' && Sys.win32 then '\\' else c in
-        (String.init (String.length flexlink) f) ^ " %%FLEXLINK_FLAGS%%" in
-      flexlink ^ "%%FLEXLINK_DLL_LDFLAGS%%",
-      flexlink ^ " -exe%%FLEXLINK_LDFLAGS%%",
-      flexlink ^ " -maindll%%FLEXLINK_DLL_LDFLAGS%%"
-    with Not_found ->
-      "%%MKDLL%%", "%%MKEXE%%", "%%MKMAINDLL%%"
+        Option.value ~default:"flexlink" (Sys.getenv_opt "OCAML_FLEXLINK")
+      in
+      let f i =
+        let c = flexlink.[i] in
+        if c = '/' && Sys.win32 then '\\' else c
+      in
+      String.init (String.length flexlink) f
+    in
+    let flags = " -chain %%FLEXDLL_CHAIN%% %%FLEXLINK_FLAGS%%" in
+    flexlink ^ flags ^ "%%FLEXLINK_DLL_LDFLAGS%%",
+    flexlink ^ " -exe" ^ flags ^ "%%FLEXLINK_LDFLAGS%%",
+    flexlink ^ " -maindll" ^ flags ^ "%%FLEXLINK_DLL_LDFLAGS%%"
   else
     "%%MKDLL%%", "%%MKEXE%%", "%%MKMAINDLL%%"
 
-- 
cgit v1.2.1