configure: Prefix libc-related variables with "libc_"

Simplifies host/target libc detection splitting.

configure

@@ -1332,6 +1332,7 @@ HAVE_LIST="
     isatty
     jack_port_get_latency_range
     ldbrx
+    libc_msvcrt
     libdc1394_1
     libdc1394_2
     local_aligned_16
@@ -1349,7 +1350,6 @@ HAVE_LIST="
     mm_empty
     mmap
     mprotect
-    msvcrt
     nanosleep
     poll_h
     posix_memalign
@@ -1557,7 +1557,7 @@ need_memalign="altivec neon sse"
 
 symver_if_any="symver_asm_label symver_gnu_asm"
 
-log2_deps="!msvcrt"
+log2_deps="!libc_msvcrt"
 
 # subsystems
 dct_select="rdft"
@@ -3413,7 +3413,7 @@ elif check_cpp_condition sys/brand.h "defined SOLARIS_BRAND_NAME"; then
     add_cppflags -D__EXTENSIONS__ -D_XOPEN_SOURCE=600
 fi
 
-test -n "$libc_type" && enable $libc_type
+test -n "$libc_type" && enable libc_$libc_type
 
 case $libc_type in
     bionic)
@@ -3429,7 +3429,7 @@ esac
 
 # hacks for compiler/libc/os combinations
 
-if enabled_all tms470 glibc; then
+if enabled_all tms470 libc_glibc; then
     CPPFLAGS="-I${source_path}/compat/tms470 ${CPPFLAGS}"
     add_cppflags -D__USER_LABEL_PREFIX__=
     add_cppflags -D__builtin_memset=memset
@@ -3437,7 +3437,7 @@ if enabled_all tms470 glibc; then
     add_cflags   -pds=48    # incompatible redefinition of macro
 fi
 
-if enabled_all ccc glibc; then
+if enabled_all ccc libc_glibc; then
     add_ldflags -Wl,-z,now  # calls to libots crash without this
 fi
 

libavcodec/Makefile

@@ -25,8 +25,6 @@ OBJS = allcodecs.o                                                      \
        raw.o                                                            \
        utils.o                                                          \
 
-OBJS-$(HAVE_MSVCRT) += file_open.o
-
 # parts needed for many different codecs
 OBJS-$(CONFIG_AANDCTTABLES)            += aandcttab.o
 OBJS-$(CONFIG_AC3DSP)                  += ac3dsp.o
@@ -677,6 +675,7 @@ OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF)       += remove_extradata_bsf.o
 OBJS-$(CONFIG_TEXT2MOVSUB_BSF)            += movsub_bsf.o
 
 # thread libraries
+OBJS-$(HAVE_LIBC_MSVCRT)               += file_open.o
 OBJS-$(HAVE_PTHREADS)                  += pthread.o pthread_slice.o pthread_frame.o
 OBJS-$(HAVE_W32THREADS)                += pthread.o pthread_slice.o pthread_frame.o
 

libavdevice/Makefile

@@ -7,8 +7,6 @@ HEADERS = avdevice.h                                                    \
 OBJS    = alldevices.o                                                  \
           avdevice.o                                                    \
 
-OBJS-$(HAVE_MSVCRT) += file_open.o
-
 # input/output devices
 OBJS-$(CONFIG_ALSA_INDEV)                += alsa-audio-common.o \
                                             alsa-audio-dec.o
@@ -31,6 +29,8 @@ OBJS-$(CONFIG_X11GRAB_INDEV)             += x11grab.o
 OBJS-$(CONFIG_LIBCDIO_INDEV)             += libcdio.o
 OBJS-$(CONFIG_LIBDC1394_INDEV)           += libdc1394.o
 
+OBJS-$(HAVE_LIBC_MSVCRT)                 += file_open.o
+
 SKIPHEADERS-$(HAVE_ALSA_ASOUNDLIB_H)     += alsa-audio.h
 SKIPHEADERS-$(HAVE_SNDIO_H)              += sndio_common.h
 

libavformat/Makefile

@@ -23,8 +23,6 @@ OBJS = allformats.o         \
        url.o                \
        utils.o              \
 
-OBJS-$(HAVE_MSVCRT) += file_open.o
-
 OBJS-$(CONFIG_NETWORK)                   += network.o
 OBJS-$(CONFIG_RIFFDEC)                   += riffdec.o
 OBJS-$(CONFIG_RIFFENC)                   += riffenc.o
@@ -388,6 +386,8 @@ OBJS-$(CONFIG_TLS_PROTOCOL)              += tls.o
 OBJS-$(CONFIG_UDP_PROTOCOL)              += udp.o
 OBJS-$(CONFIG_UNIX_PROTOCOL)             += unix.o
 
+OBJS-$(HAVE_LIBC_MSVCRT)                 += file_open.o
+
 SKIPHEADERS-$(CONFIG_FFRTMPCRYPT_PROTOCOL) += rtmpdh.h
 SKIPHEADERS-$(CONFIG_NETWORK)            += network.h rtsp.h
 

libavutil/internal.h

@@ -204,7 +204,7 @@ void avpriv_report_missing_feature(void *avc,
 void avpriv_request_sample(void *avc,
                            const char *msg, ...) av_printf_format(2, 3);
 
-#if HAVE_MSVCRT
+#if HAVE_LIBC_MSVCRT
 #define avpriv_open ff_open
 #endif