Add --trap-mode=allow/clamp/js argument to asm2wasm and s2wasm (#1210)

* Add --trap-mode=allow/clamp/js argument to asm2wasm and s2wasm

* Update asm2wasm and auto_update_tests scripts to use --trap-mode

* Throw std::invalid_argument instead of adding a new Invalid TrapMode type

* Remove legacy asm2wasm trap mode arguments

Author: jgravelle-google

auto_update_tests.py

@@ -19,10 +19,10 @@
         cmd = ASM2WASM + [os.path.join('test', asm)]
         wasm = asm.replace('.asm.js', '.fromasm')
         if not precise:
-          cmd += ['--emit-potential-traps', '--ignore-implicit-traps']
+          cmd += ['--trap-mode=allow', '--ignore-implicit-traps']
           wasm += '.imprecise'
         elif precise == 2:
-          cmd += ['--emit-clamped-potential-traps']
+          cmd += ['--trap-mode=clamp']
           wasm += '.clamp'
         if not opts:
           wasm += '.no-opts'

scripts/test/asm2wasm.py

@@ -35,10 +35,10 @@ def test_asm2wasm():
         cmd = ASM2WASM + [os.path.join(options.binaryen_test, asm)]
         wasm = asm.replace('.asm.js', '.fromasm')
         if not precise:
-          cmd += ['--emit-potential-traps', '--ignore-implicit-traps']
+          cmd += ['--trap-mode=allow', '--ignore-implicit-traps']
           wasm += '.imprecise'
         elif precise == 2:
-          cmd += ['--emit-clamped-potential-traps']
+          cmd += ['--trap-mode=clamp']
           wasm += '.clamp'
         if not opts:
           wasm += '.no-opts'

scripts/test/s2wasm.py

@@ -34,8 +34,8 @@ def test_s2wasm():
 
   extension_arg_map = {
       '.wast': [],
-      '.clamp.wast': ['--emit-clamped-potential-traps'],
-      '.js.wast': ['--emit-jsified-potential-traps'],
+      '.clamp.wast': ['--trap-mode=clamp'],
+      '.js.wast': ['--trap-mode=js'],
   }
   for dot_s_dir in ['dot_s', 'llvm_autogenerated']:
     dot_s_path = os.path.join(options.binaryen_test, dot_s_dir)

src/ast/trapping.h

@@ -17,6 +17,8 @@
 #ifndef wasm_ast_trapping_h
 #define wasm_ast_trapping_h
 
+#include <exception>
+
 #include "pass.h"
 
 namespace wasm {
@@ -95,6 +97,20 @@ class TrappingFunctionContainer {
 Expression* makeTrappingBinary(Binary* curr, TrappingFunctionContainer &trappingFunctions);
 Expression* makeTrappingUnary(Unary* curr, TrappingFunctionContainer &trappingFunctions);
 
+inline TrapMode trapModeFromString(std::string const& str) {
+  if (str == "allow") {
+    return TrapMode::Allow;
+  } else if (str == "clamp") {
+    return TrapMode::Clamp;
+  } else if (str == "js") {
+    return TrapMode::JS;
+  } else {
+    throw std::invalid_argument(
+      "Unsupported trap mode \"" + str + "\". "
+      "Valid modes are \"allow\", \"js\", and \"clamp\"");
+  }
+}
+
 } // wasm
 
 #endif // wasm_ast_trapping_h

src/tools/asm2wasm.cpp

@@ -18,6 +18,8 @@
 // asm2wasm console tool
 //
 
+#include <exception>
+
 #include "ast/trapping.h"
 #include "support/colors.h"
 #include "support/command-line.h"
@@ -78,21 +80,17 @@ int main(int argc, const char *argv[]) {
            [](Options *o, const std::string &) {
              std::cerr << "--no-opts is deprecated (use -O0, etc.)\n";
            })
-      .add("--emit-potential-traps", "-i", "Emit instructions that might trap, like div/rem of 0", Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::Allow;
-           })
-      .add("--emit-clamped-potential-traps", "-i", "Clamp instructions that might trap, like float => int", Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::Clamp;
-           })
-      .add("--emit-jsified-potential-traps", "-i", "Avoid instructions that might trap, handling them exactly like JS would", Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::JS;
-           })
-      .add("--imprecise", "-i", "Imprecise optimizations (old name for --emit-potential-traps)", Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::Allow;
+      .add("--trap-mode", "",
+           "Strategy for handling potentially trapping instructions. Valid "
+             "values are \"allow\", \"js\", and \"clamp\"",
+           Options::Arguments::One,
+           [&trapMode](Options *o, const std::string &argument) {
+             try {
+               trapMode = trapModeFromString(argument);
+             } catch (std::invalid_argument e) {
+               std::cerr << "Error: " << e.what() << "\n";
+               exit(EXIT_FAILURE);
+             }
            })
       .add("--wasm-only", "-w", "Input is in WebAssembly-only format, and not actually valid asm.js", Options::Arguments::Zero,
            [&wasmOnly](Options *o, const std::string &) {

src/tools/s2wasm.cpp

@@ -15,9 +15,11 @@
  */
 
 //
-// wasm2asm console tool
+// s2wasm console tool
 //
 
+#include <exception>
+
 #include "ast/trapping.h"
 #include "support/colors.h"
 #include "support/command-line.h"
@@ -83,23 +85,17 @@ int main(int argc, const char *argv[]) {
            [&allowMemoryGrowth](Options *, const std::string &) {
              allowMemoryGrowth = true;
            })
-      .add("--emit-potential-traps", "",
-           "Emit instructions that might trap, like div/rem of 0",
-           Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::Allow;
-           })
-      .add("--emit-clamped-potential-traps", "",
-           "Clamp instructions that might trap, like float => int",
-           Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::Clamp;
-           })
-      .add("--emit-jsified-potential-traps", "",
-           "Avoid instructions that might trap, handling them exactly like JS would",
-           Options::Arguments::Zero,
-           [&trapMode](Options *o, const std::string &) {
-             trapMode = TrapMode::JS;
+      .add("--trap-mode", "",
+           "Strategy for handling potentially trapping instructions. Valid "
+             "values are \"allow\", \"js\", and \"clamp\"",
+           Options::Arguments::One,
+           [&trapMode](Options *o, const std::string &argument) {
+             try {
+               trapMode = trapModeFromString(argument);
+             } catch (std::invalid_argument e) {
+               std::cerr << "Error: " << e.what() << "\n";
+               exit(EXIT_FAILURE);
+             }
            })
       .add("--emscripten-glue", "-e", "Generate emscripten glue",
            Options::Arguments::Zero,