Remove support for __original_main. (WebAssembly#295)

* Remove support for `__original_main`.

This was used in old LLVM versions. Recent LLVM versions all emit either
`__main_void` or `__main_argv_argc`, so we can use those directly.

* Update the CI to use LLVM 14.0.0.

Author: Dan Gohman

.github/workflows/main.yml

@@ -23,8 +23,8 @@ jobs:
     - name: Install LLVM tools (Windows)
       shell: bash
       run: |
-        curl -fsSLO https://github.com/llvm/llvm-project/releases/download/llvmorg-10.0.0/LLVM-10.0.0-win64.exe
-        7z x LLVM-10.0.0-win64.exe -y -o"llvm"
+        curl -fsSLO https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.0/LLVM-14.0.0-win64.exe
+        7z x LLVM-14.0.0-win64.exe -y -o"llvm"
         echo "$(pwd)/llvm/bin" >> $GITHUB_PATH
         echo "CC=$(pwd)/llvm/bin/clang.exe" >> $GITHUB_ENV
         echo "AR=$(pwd)/llvm/bin/llvm-ar.exe" >> $GITHUB_ENV
@@ -42,8 +42,8 @@ jobs:
     - name: Install LLVM tools (MacOS)
       shell: bash
       run: |
-        curl -sSfL https://github.com/llvm/llvm-project/releases/download/llvmorg-10.0.0/clang+llvm-10.0.0-x86_64-apple-darwin.tar.xz | tar xJf -
-        export CLANG_DIR=`pwd`/clang+llvm-10.0.0-x86_64-apple-darwin/bin
+        curl -sSfL https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.0/clang+llvm-14.0.0-x86_64-apple-darwin.tar.xz | tar xJf -
+        export CLANG_DIR=`pwd`/clang+llvm-14.0.0-x86_64-apple-darwin/bin
         echo "$CLANG_DIR" >> $GITHUB_PATH
         echo "CC=$CLANG_DIR/clang" >> $GITHUB_ENV
         echo "AR=$CLANG_DIR/llvm-ar" >> $GITHUB_ENV
@@ -53,8 +53,8 @@ jobs:
     - name: Install LLVM tools (Linux)
       shell: bash
       run: |
-        curl -sSfL https://github.com/llvm/llvm-project/releases/download/llvmorg-10.0.0/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz | tar xJf -
-        export CLANG_DIR=`pwd`/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/bin
+        curl -sSfL https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.0/clang+llvm-14.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz | tar xJf -
+        export CLANG_DIR=`pwd`/clang+llvm-14.0.0-x86_64-linux-gnu-ubuntu-18.04/bin
         echo "$CLANG_DIR" >> $GITHUB_PATH
         echo "CLANG_DIR=$CLANG_DIR" >> $GITHUB_ENV
         echo "CC=$CLANG_DIR/clang" >> $GITHUB_ENV

expected/wasm32-wasi/defined-symbols.txt

@@ -188,7 +188,6 @@ __log2f_data
 __log_data
 __logf_data
 __lseek
-__main_argc_argv
 __main_void
 __malloc_atfork
 __math_divzero
@@ -215,7 +214,6 @@ __ofl_lock
 __ofl_unlock
 __optpos
 __optreset
-__original_main
 __overflow
 __p1evll
 __parsespent

libc-bottom-half/crt/crt1-command.c

@@ -4,7 +4,7 @@ extern void __wasi_init_tp(void);
 #endif
 #include <wasi/api.h>
 extern void __wasm_call_ctors(void);
-extern int __original_main(void);
+extern int __main_void(void);
 extern void __wasm_call_dtors(void);
 
 __attribute__((export_name("_start")))
@@ -40,7 +40,7 @@ void _start(void) {
     // Call `__main_void` which will either be the application's zero-argument
     // `__main_void` function or a libc routine which obtains the command-line
     // arguments and calls `__main_argv_argc`.
-    int r = __original_main();
+    int r = __main_void();
 
     // Call atexit functions, destructors, stdio cleanup, etc.
     __wasm_call_dtors();