From 3be32a5851b86cc55d5b91457290854ed6b1676b Mon Sep 17 00:00:00 2001
From: Alexey Andreev <konsoletyper@gmail.com>
Date: Mon, 25 Feb 2019 11:30:30 +0300
Subject: [PATCH] JS: don't generate square brackets in 'if' bodies, when
 possible. Generate mangled name for $rt_wrapException

---
 .../rendering/NameFrequencyEstimator.java     |  1 +
 .../javascript/rendering/Renderer.java        |  2 +-
 .../rendering/StatementRenderer.java          | 45 ++++++++++++++++---
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/NameFrequencyEstimator.java b/core/src/main/java/org/teavm/backend/javascript/rendering/NameFrequencyEstimator.java
index eaada83e3..90595e885 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/NameFrequencyEstimator.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/NameFrequencyEstimator.java
@@ -171,6 +171,7 @@ class NameFrequencyEstimator extends RecursiveVisitor implements MethodNodeVisit
         if (statement.getExceptionType() != null) {
             consumer.consume(statement.getExceptionType());
         }
+        consumer.consumeFunction("$rt_wrapException");
     }
 
     @Override
diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java b/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
index 83b545083..a68a30968 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
@@ -250,7 +250,7 @@ public class Renderer implements RenderingManager {
     private void renderRuntimeAliases() throws IOException {
         String[] names = { "$rt_throw", "$rt_compare", "$rt_nullCheck", "$rt_cls", "$rt_createArray",
                 "$rt_isInstance", "$rt_nativeThread", "$rt_suspending", "$rt_resuming", "$rt_invalidPointer",
-                "$rt_s", "$rt_eraseClinit", "$rt_imul" };
+                "$rt_s", "$rt_eraseClinit", "$rt_imul", "$rt_wrapException" };
         boolean first = true;
         for (String name : names) {
             if (!first) {
diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java b/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
index 8775e93ed..a69c07cea 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
@@ -190,6 +190,7 @@ public class StatementRenderer implements ExprVisitor, StatementVisitor {
     @Override
     public void visit(ConditionalStatement statement) {
         try {
+            boolean needClosingBracket;
             while (true) {
                 debugEmitter.emitStatementStart();
                 if (statement.getCondition().getLocation() != null) {
@@ -203,27 +204,60 @@ public class StatementRenderer implements ExprVisitor, StatementVisitor {
                     popLocation();
                 }
                 debugEmitter.emitCallSite();
-                writer.append(")").ws().append("{").softNewLine().indent();
+                writer.append(")");
+                if (isSimpleIfContent(statement.getConsequent())) {
+                    needClosingBracket = false;
+                } else {
+                    writer.ws().append("{");
+                    needClosingBracket = true;
+                }
+                writer.softNewLine().indent();
                 visitStatements(statement.getConsequent());
+
                 if (!statement.getAlternative().isEmpty()) {
-                    writer.outdent().append("}").ws();
+                    writer.outdent();
+                    if (needClosingBracket) {
+                        writer.append("}").ws();
+                    }
                     if (statement.getAlternative().size() == 1
                             && statement.getAlternative().get(0) instanceof ConditionalStatement) {
                         statement = (ConditionalStatement) statement.getAlternative().get(0);
                         writer.append("else ");
                         continue;
                     }
-                    writer.append("else").ws().append("{").indent().softNewLine();
+                    writer.append("else");
+                    if (isSimpleIfContent(statement.getAlternative())) {
+                        if (minifying) {
+                            writer.append(" ");
+                        }
+                        needClosingBracket = false;
+                    } else {
+                        writer.ws().append("{");
+                        needClosingBracket = true;
+                    }
+                    writer.indent().softNewLine();
                     visitStatements(statement.getAlternative());
                 }
                 break;
             }
-            writer.outdent().append("}").softNewLine();
+            writer.outdent();
+            if (needClosingBracket) {
+                writer.append("}").softNewLine();
+            }
         } catch (IOException e) {
             throw new RenderingException("IO error occurred", e);
         }
     }
 
+    private boolean isSimpleIfContent(List<Statement> statements) {
+        if (statements.size() != 1) {
+            return false;
+        }
+
+        Statement statement = statements.get(0);
+        return !(statement instanceof ConditionalStatement);
+    }
+
     @Override
     public void visit(SwitchStatement statement) {
         try {
@@ -1408,7 +1442,8 @@ public class StatementRenderer implements ExprVisitor, StatementVisitor {
             visitStatements(protectedBody);
             writer.outdent().append("}").ws().append("catch").ws().append("($$e)")
                     .ws().append("{").indent().softNewLine();
-            writer.append("$$je").ws().append("=").ws().append("$rt_wrapException($$e);").softNewLine();
+            writer.append("$$je").ws().append("=").ws().appendFunction("$rt_wrapException").append("($$e);")
+                    .softNewLine();
             boolean first = true;
             boolean defaultHandlerOccurred = false;
             for (TryCatchStatement catchClause : sequence) {