Avoid calling main method of GraalWasm C tests

Newer versions of Emscripten unconditionally call exit at the end of
main. In our test harness, however, we want to run the test
repeatedly to test compilation.

Author: jirkamarsik

wasm/mx.wasm/mx_wasm.py

@@ -445,6 +445,17 @@ def __str__(self):
     def benchmark_methods(self):
         return benchmark_methods
 
+    def test_methods(self, opts_path):
+        if not os.path.isfile(opts_path):
+            return []
+        with open(opts_path) as opts_file:
+            for line in opts_file:
+                line = line.strip()
+                if line.startswith("entry-point"):
+                    _, value = line.split("=", 1)
+                    return ['_' + value.strip()]
+        return []
+
     def build(self):
         source_dir = self.subject.getSourceDir()
         output_dir = self.subject.getOutputDir()
@@ -469,8 +480,6 @@ def build(self):
         if hasattr(self.project, "includeset"):
             include_flags = ["-I", os.path.join(_suite.dir, "includes", self.project.includeset)]
         emcc_flags = ["-s", "STANDALONE_WASM", "-s", "WASM_BIGINT"] + cc_flags
-        if self.project.isBenchmarkProject():
-            emcc_flags = emcc_flags + ["-s", "EXPORTED_FUNCTIONS=" + str(self.benchmark_methods()).replace("'", "\"") + ""]
         subdir_program_names = defaultdict(lambda: [])
         for root, filename in self.subject.getProgramSources():
             if filename.startswith("_"):
@@ -502,9 +511,13 @@ def build(self):
             # Step 1: build the .wasm binary.
             if mustRebuild:
                 if filename.endswith(".c"):
+                    if self.project.isBenchmarkProject():
+                        emcc_export_flags = ["-s", "EXPORTED_FUNCTIONS=" + str(self.benchmark_methods()).replace("'", "\"") + ""]
+                    else:
+                        emcc_export_flags = ["-s", "EXPORTED_FUNCTIONS=" + str(self.test_methods(os.path.join(root, basename + ".opts"))).replace("'", "\"") + ""]
                     # This generates both a js file and a wasm file.
                     # See https://github.com/emscripten-core/emscripten/wiki/WebAssembly-Standalone
-                    build_cmd_line = [emcc_cmd] + emcc_flags + source_cc_flags + [source_path, "-o", output_js_path] + include_flags
+                    build_cmd_line = [emcc_cmd] + emcc_flags + emcc_export_flags + source_cc_flags + [source_path, "-o", output_js_path] + include_flags
                     if mx.run(build_cmd_line, nonZeroIsFatal=False) != 0:
                         mx.abort("Could not build the wasm-only output of " + filename + " with emcc.")
                 elif filename.endswith(".wat"):

wasm/src/org.graalvm.wasm.test/src/org/graalvm/wasm/test/WasmFileSuite.java

@@ -216,9 +216,21 @@ private void runInContext(WasmCase testCase, Context context, List<Source> sourc
             }
 
             final WasmContext wasmContext = WasmContext.get(null);
-            final Value mainFunction = findMain(moduleInstances);
             final List<WasmInstance> instanceList = moduleInstances.stream().map(i -> toWasmInstance(i)).toList();
 
+            final Value testFunction;
+            final String entryPoint = testCase.options().getProperty("entry-point");
+            if (entryPoint != null) {
+                String testModuleName = testCase.name();
+                Value testModule = context.getBindings(WasmLanguage.ID).getMember(testModuleName).getMember("exports");
+                testFunction = testModule.getMember(entryPoint);
+                if (testFunction == null) {
+                    throw new RuntimeException(String.format("Entry point %s not found in test module %s.", entryPoint, testCase.name()));
+                }
+            } else {
+                testFunction = findMain(moduleInstances);
+            }
+
             resetStatus(System.out, phaseIcon, phaseLabel);
 
             final String argString = testCase.options().getProperty("argument");
@@ -228,7 +240,7 @@ private void runInContext(WasmCase testCase, Context context, List<Source> sourc
             for (int i = 0; i != iterations; ++i) {
                 try {
                     testOut.reset();
-                    final Value result = arg == null ? mainFunction.execute() : mainFunction.execute(arg);
+                    final Value result = arg == null ? testFunction.execute() : testFunction.execute(arg);
                     WasmCase.validateResult(testCase.data().resultValidator(), result, testOut);
                 } catch (PolyglotException e) {
                     // If no exception is expected and the program returns with success exit status,

wasm/src/org.graalvm.wasm.testcases/src/test/c/allocate-string.c

@@ -42,7 +42,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-int main() {
+int test() {
   char staticMemory[100];
   char *dynamicMemory;
 
@@ -59,3 +59,7 @@ int main() {
   printf("2nd: %s\n", dynamicMemory);
   return 0;
 }
+
+int main() {
+  return test();
+}

wasm/src/org.graalvm.wasm.testcases/src/test/c/allocate-string.opts

@@ -3,3 +3,4 @@ interpreter-iterations = 2
 sync-noinline-iterations = 0
 sync-inline-iterations = 0
 async-iterations = 2000
+entry-point = test

wasm/src/org.graalvm.wasm.testcases/src/test/c/collatz.c

@@ -56,8 +56,11 @@ int collatz(int n) {
 
 int number = 127;
 
-int main() {
+int test() {
   printf("%d\n", collatz(number));
   return 0;
 }
 
+int main() {
+  return test();
+}

wasm/src/org.graalvm.wasm.testcases/src/test/c/collatz.opts

@@ -0,0 +1 @@
+entry-point = test

wasm/src/org.graalvm.wasm.testcases/src/test/c/floyd.c

@@ -41,7 +41,7 @@
 
 #include <stdio.h>
 
-int main() {
+int test() {
   int number = 1;
   int rows = 10;
   for (int i = 1; i <= rows; i++) {
@@ -53,3 +53,7 @@ int main() {
   }
   return 0;
 }
+
+int main() {
+  return test();
+}

wasm/src/org.graalvm.wasm.testcases/src/test/c/floyd.opts

@@ -3,3 +3,4 @@ interpreter-iterations = 4
 sync-noinline-iterations = 0
 sync-inline-iterations = 0
 async-iterations = 500
+entry-point = test

wasm/src/org.graalvm.wasm.testcases/src/test/c/hello.c

@@ -40,8 +40,11 @@
  */
 #include <stdio.h>
 
-int main() {
+int test() {
   printf("Hello world!\n");
   return 0;
 }
 
+int main() {
+  return test();
+}

wasm/src/org.graalvm.wasm.testcases/src/test/c/hello.opts

@@ -3,3 +3,4 @@ interpreter-iterations = 3
 sync-noinline-iterations = 2
 sync-inline-iterations = 2
 async-iterations = 1250
+entry-point = test