windows: fix linking .rc to shared curl with autotools

`./configure --enable-shared --disable-static` fails when trying to link
a shared `curl.exe`, due to `libtool` magically changing the output
filename of `windres` to one that it doesn't find when linking:

```
/bin/sh ../libtool --tag=RC --mode=compile windres -I../../curl/include -DCURL_EMBED_MANIFEST  -i ../../curl/src/curl.rc -o curl.o
libtool: compile:  windres -I../../curl/include -DCURL_EMBED_MANIFEST -i ../../curl/src/curl.rc  -o .libs/curl.o
[...]
CCLD     curl.exe
clang: error: no such file or directory: 'curl.o'
```

Let's resolve this by skipping `libtool` and calling `windres` directly
when building `src` (aka `curl.exe`). Leave `lib` unchanged, as it does
need the `libtool` magic. This solution is compatible with building
a static `curl.exe`.

This build scenario is not CI-tested.

While here, delete an obsolete comment about a permanent `libtool`
warning that we've resolved earlier.

Regression from 6de7322c03d5b4d91576a7d9fc893e03cc9d1057

Reported-by: Christoph Reiter
Fixes #9803
Closes #9805

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 5d2df8bffb1761420e89e225366738197dd14155..cd1ca97a54df308e2bc8331f01fa2c2cd50e60b7 100644 (file)
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -155,7 +155,6 @@ optiontable:
        perl optiontable.pl < $(top_srcdir)/include/curl/curl.h > easyoptions.c
 
 if OS_WINDOWS
-# Warning is "normal": libtool:   error: ignoring unknown tag RC
 .rc.lo:
        $(LIBTOOL) --tag=RC --mode=compile $(RC) -I$(top_srcdir)/include $(RCFLAGS) -i $< -o $@
 endif

diff --git a/src/Makefile.am b/src/Makefile.am
index d9180b0b148270289302e95bf1f07663858aa05d..2c1886f5a838abdf274ae6a8fe3dec54bf3bc81d 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -157,7 +157,6 @@ listhelp:
        (cd $(top_srcdir)/docs/cmdline-opts && ./gen.pl listhelp *.d) > tool_listhelp.c
 
 if OS_WINDOWS
-# Warning is "normal": libtool:   error: ignoring unknown tag RC
 .rc.o:
-       $(LIBTOOL) --tag=RC --mode=compile $(RC) -I$(top_srcdir)/include -DCURL_EMBED_MANIFEST $(RCFLAGS) -i $< -o $@
+       $(RC) -I$(top_srcdir)/include -DCURL_EMBED_MANIFEST $(RCFLAGS) -i $< -o $@
 endif