[src,build] Support web assembly for online2 tcp decoding (kaldi-asr#…

…4276)

README.md

@@ -66,3 +66,10 @@ Platform specific notes
   OpenBLAS.
 - See [this blog post](http://jcsilva.github.io/2017/03/18/compile-kaldi-android/)
   for details.
+
+### Web Assembly
+
+- Kaldi supports cross compiling for Web Assembly for in-browser execution
+  using [emscripten](https://emscripten.org/) and CLAPACK.
+- See [this post](https://gitlab.inria.fr/kaldi.web/kaldi-wasm/-/wikis/build_details.md)
+  for a step-by-step description of the build process.

src/configure

@@ -767,28 +767,35 @@ if $android && [[ "$CXX" != *clang++*  ]] ; then
 fi
 
 # If HOST is set
-# 1. We prepend it to CXX, AR, AS and RANLIB.
-# 2. We parse the target architecture from the HOST triple.
+# - If it is not equal to WASM
+#   1. We prepend it to CXX, AR, AS and RANLIB.
+#   2. We parse the target architecture from the HOST triple.
+# - Otherwise we take its value as the target architecture
 # Otherwise we set the target architecture to the output of `uname -m`.
 if is_set $HOST; then
-  CXX="$HOST-$CXX"
-  AR="$HOST-$AR"
-  AS="$HOST-$AS"
-  RANLIB="$HOST-$RANLIB"
-
   # The host triple will be something like "armv8-rpi3-linux-gnueabihf". We
   # need the first field which is the target architecture for this build. The
   # following command will take the host triple "armv8-rpi3-linux-gnueabihf"
   # and return ["armv8", "rpi3", "linux", "gnueabihf"] in PARTS.
   IFS='-' read -ra PARTS <<< "$HOST"
-  # The first field in the PARTS list is the target architecture.
-  TARGET_ARCH="$PARTS"
-  if [[ "$TARGET_ARCH" != aarch64* && "$TARGET_ARCH" != arm* && "$TARGET_ARCH" != ppc64le && \
-        "$TARGET_ARCH" != x86* && "$TARGET_ARCH" != i686* ]] ; then
-    # We currently only support building for x86[_64], arm*, aarch64* and ppc64le.
-    # If TARGET_ARCH was read from the HOST variable, it must be one of these.
-    failure "$TARGET_ARCH is not a supported architecture.
-             Supported architectures: x86[_64], arm*, aarch64*, ppc64le."
+
+  if [[ "$HOST" != WASM ]]; then
+    CXX="$HOST-$CXX"
+    AR="$HOST-$AR"
+    AS="$HOST-$AS"
+    RANLIB="$HOST-$RANLIB"
+
+    # The first field in the PARTS list is the target architecture.
+    TARGET_ARCH="$PARTS"
+    if [[ "$TARGET_ARCH" != aarch64* && "$TARGET_ARCH" != arm* && "$TARGET_ARCH" != ppc64le && \
+          "$TARGET_ARCH" != x86* && "$TARGET_ARCH" != i686* ]] ; then
+      # We currently only support building for x86[_64], arm*, aarch64* and ppc64le.
+      # If TARGET_ARCH was read from the HOST variable, it must be one of these.
+      failure "$TARGET_ARCH is not a supported architecture.
+      Supported architectures: x86[_64], arm*, aarch64*, ppc64le."
+    fi
+  else
+    TARGET_ARCH="$HOST"
   fi
 else
   TARGET_ARCH="`uname -m`"
@@ -878,6 +885,10 @@ echo >> kaldi.mk
 echo "Checking compiler $CXX ..."
 check_compiler $CXX
 
+echo "# Target achitecture" >> kaldi.mk
+echo "ARCH = $TARGET_ARCH" >> kaldi.mk
+echo >> kaldi.mk
+
 echo "# Base configuration" >> kaldi.mk
 echo >> kaldi.mk
 if $dynamic_kaldi ; then

src/makefiles/darwin_clapack.mk

@@ -22,7 +22,7 @@ CXXFLAGS = -std=c++11 -I.. -I$(OPENFSTINC) -O1 $(EXTRA_CXXFLAGS) \
            -Wno-deprecated-declarations -Winit-self \
            -DKALDI_DOUBLEPRECISION=$(DOUBLE_PRECISION) \
            -DHAVE_EXECINFO_H=1 -DHAVE_CXXABI_H -DHAVE_CLAPACK -I../../tools/CLAPACK \
-           -msse -msse2 -pthread \
+           -msse -msse2 \
            -g
 
 ifeq ($(KALDI_FLAVOR), dynamic)
@@ -47,4 +47,9 @@ CXXFLAGS += -flax-vector-conversions
 endif
 
 LDFLAGS = $(EXTRA_LDFLAGS) $(OPENFSTLDFLAGS) -g
-LDLIBS = $(EXTRA_LDLIBS) $(OPENFSTLIBS) $(CLAPACKLIBS) -lm -lpthread -ldl
+LDLIBS = $(EXTRA_LDLIBS) $(OPENFSTLIBS) $(CLAPACKLIBS) -lm -ldl
+
+ifneq ($(ARCH), WASM)
+    CXXFLAGS += -pthread
+    LDLIBS += -lpthread
+endif

src/makefiles/linux_clapack.mk

@@ -22,7 +22,7 @@ CXXFLAGS = -std=c++11 -I.. -isystem $(OPENFSTINC) -O1 $(EXTRA_CXXFLAGS) \
            -Wno-deprecated-declarations -Winit-self \
            -DKALDI_DOUBLEPRECISION=$(DOUBLE_PRECISION) \
            -DHAVE_EXECINFO_H=1 -DHAVE_CXXABI_H -DHAVE_CLAPACK -I../../tools/CLAPACK \
-           -msse -msse2 -pthread \
+           -msse -msse2 \
            -g
 
 ifeq ($(KALDI_FLAVOR), dynamic)
@@ -44,4 +44,9 @@ CXXFLAGS += -Wno-mismatched-tags
 endif
 
 LDFLAGS = $(EXTRA_LDFLAGS) $(OPENFSTLDFLAGS) -rdynamic
-LDLIBS = $(EXTRA_LDLIBS) $(OPENFSTLIBS) $(CLAPACKLIBS) -lm -lpthread -ldl
+LDLIBS = $(EXTRA_LDLIBS) $(OPENFSTLIBS) $(CLAPACKLIBS) -lm -ldl
+
+ifneq ($(ARCH), WASM)
+    CXXFLAGS += -pthread
+    LDLIBS += -lpthread
+endif

src/online2bin/Makefile

@@ -15,6 +15,11 @@ BINFILES = online2-wav-gmm-latgen-faster apply-cmvn-online \
      online2-tcp-nnet3-decode-faster online2-wav-nnet3-latgen-incremental \
      online2-wav-nnet3-wake-word-decoder-faster
 
+# ARCH is defined in kaldi.mk
+ifeq ($(ARCH), WASM)
+    BINFILES += online2-tcp-nnet3-decode-faster-emscripten
+endif
+
 OBJFILES =
 
 TESTFILES =