[FFmpeg-devel] [PATCH] build: make sure probed tools don't wait for stdin input.

[Clément Bœsch]

a758c5e added probing for various tools, such as as. Unfortunately, GNU
as is reading stdin with -v, and thus configure is stalled with
configure arguments such as --as=as.

The --version calls are unchanged because it is supposed to -v + exit.

Fixes Ticket #1898.
---
 configure | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/configure b/configure
index 576905c..5dd27c9 100755
--- a/configure
+++ b/configure
@@ -2545,14 +2545,14 @@ probe_cc(){
     unset _depflags _DEPCMD _DEPFLAGS
     _flags_filter=echo
 
-    if $_cc -v 2>&1 | grep -q '^gcc.*LLVM'; then
+    if $_cc -v 2>&1 < /dev/null | grep -q '^gcc.*LLVM'; then
         _type=llvm_gcc
         gcc_extra_ver=$(expr "$($_cc --version | head -n1)" : '.*\((.*)\)')
         _ident="llvm-gcc $($_cc -dumpversion) $gcc_extra_ver"
         _depflags='-MMD -MF $(@:.o=.d) -MT $@'
         _cflags_speed='-O3'
         _cflags_size='-Os'
-    elif $_cc -v 2>&1 | grep -qi ^gcc; then
+    elif $_cc -v 2>&1 < /dev/null | grep -qi ^gcc; then
         _type=gcc
         gcc_version=$($_cc --version | head -n1)
         gcc_basever=$($_cc -dumpversion)
@@ -2571,19 +2571,19 @@ probe_cc(){
         _cflags_speed='-O3'
         _cflags_size='-Os'
         _cflags_noopt='-O1'
-    elif $_cc -v 2>&1 | grep -q xlc; then
+    elif $_cc -v 2>&1 < /dev/null | grep -q xlc; then
         _type=xlc
         _ident=$($_cc -qversion 2>/dev/null | head -n1)
         _cflags_speed='-O5'
         _cflags_size='-O5 -qcompact'
-    elif $_cc -V 2>/dev/null | grep -q Compaq; then
+    elif $_cc -V 2>/dev/null < /dev/null | grep -q Compaq; then
         _type=ccc
         _ident=$($_cc -V | head -n1 | cut -d' ' -f1-3)
         _DEPFLAGS='-M'
         _cflags_speed='-fast'
         _cflags_size='-O1'
         _flags_filter=ccc_flags
-    elif $_cc --vsn 2>/dev/null | grep -q "ARM C/C++ Compiler"; then
+    elif $_cc --vsn 2>/dev/null < /dev/null | grep -q "ARM C/C++ Compiler"; then
         test -d "$sysroot" || die "No valid sysroot specified."
         _type=armcc
         _ident=$($_cc --vsn | head -n1)
@@ -2609,13 +2609,13 @@ probe_cc(){
         _cflags_speed='-O3 -mf=5'
         _cflags_size='-O3 -mf=2'
         _flags_filter=tms470_flags
-    elif $_cc -v 2>&1 | grep -q clang; then
+    elif $_cc -v 2>&1 < /dev/null | grep -q clang; then
         _type=clang
         _ident=$($_cc --version | head -n1)
         _depflags='-MMD'
         _cflags_speed='-O3'
         _cflags_size='-Os'
-    elif $_cc -V 2>&1 | grep -q Sun; then
+    elif $_cc -V 2>&1 < /dev/null | grep -q Sun; then
         _type=suncc
         _ident=$($_cc -V 2>&1 | head -n1 | cut -d' ' -f 2-)
         _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< | sed -e "1s,^.*: ,$@: ," -e "\$$!s,\$$, \\\," -e "1!s,^.*: , ," > $(@:.o=.d)'
@@ -2624,21 +2624,21 @@ probe_cc(){
         _cflags_speed='-O5'
         _cflags_size='-O5 -xspace'
         _flags_filter=suncc_flags
-    elif $_cc -v 2>&1 | grep -q 'PathScale\|Path64'; then
+    elif $_cc -v 2>&1 < /dev/null | grep -q 'PathScale\|Path64'; then
         _type=pathscale
         _ident=$($_cc -v 2>&1 | head -n1 | tr -d :)
         _depflags='-MMD -MF $(@:.o=.d) -MT $@'
         _cflags_speed='-O2'
         _cflags_size='-Os'
         _flags_filter='filter_out -Wdisabled-optimization'
-    elif $_cc -v 2>&1 | grep -q Open64; then
+    elif $_cc -v 2>&1 < /dev/null | grep -q Open64; then
         _type=open64
         _ident=$($_cc -v 2>&1 | head -n1 | tr -d :)
         _depflags='-MMD -MF $(@:.o=.d) -MT $@'
         _cflags_speed='-O2'
         _cflags_size='-Os'
         _flags_filter='filter_out -Wdisabled-optimization|-Wtype-limits|-fno-signed-zeros'
-    elif $_cc -V 2>&1 | grep -q Portland; then
+    elif $_cc -V 2>&1 < /dev/null | grep -q Portland; then
         _type=pgi
         _ident="PGI $($_cc -V 2>&1 | awk '/^pgcc/ { print $2; exit }')"
         opt_common='-alias=ansi -Mdse -Mlre -Mpre'
@@ -2646,7 +2646,7 @@ probe_cc(){
         _cflags_size="-O2 -Munroll=c:1 $opt_common"
         _cflags_noopt="-O1"
         _flags_filter=pgi_flags
-    elif $_cc 2>&1 | grep -q Microsoft; then
+    elif $_cc 2>&1 < /dev/null | grep -q Microsoft; then
         _type=msvc
         _ident=$($cc 2>&1 | head -n1)
         _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< 2>&1 | awk '\''/including/ { sub(/^.*file: */, ""); gsub(/\\/, "/"); if (!match($$0, / /)) print "$@:", $$0 }'\'' > $(@:.o=.d)'
@@ -2654,7 +2654,7 @@ probe_cc(){
         _cflags_speed="-O2"
         _cflags_size="-O1"
         # Nonstandard output options, to avoid msys path conversion issues, relies on wrapper to remap it
-        if $_cc 2>&1 | grep -q Linker; then
+        if $_cc 2>&1 < /dev/null | grep -q Linker; then
             _ld_o='-out $@'
         else
             _ld_o='-Fe$@'
-- 
1.8.1