Allow space before preprocessor directives

src/generator-impl.ts

@@ -412,9 +412,10 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
       previousLineWasEmpty = false;
     }
 
-    if (line.startsWith("#")) {
-      if (line.startsWith("#use ")) {
-        const uses = line
+    if (line.trim().startsWith("#")) {
+      const trimmedLine = line.trimStart();
+      if (trimmedLine.startsWith("#use ")) {
+        const uses = trimmedLine
           .slice(5)
           .split(" ")
           .filter((s) => s.trim())
@@ -430,8 +431,8 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
           }
           patterns.push(pattern);
         }
-      } else if (line.startsWith("#param ")) {
-        const params = line
+      } else if (trimmedLine.startsWith("#param ")) {
+        const params = trimmedLine
           .slice(7)
           .split(" ")
           .filter((s) => s.trim())
@@ -467,7 +468,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
             // otherwise silently ignore duplicate
           }
         }
-      } else if (line.startsWith("#if ")) {
+      } else if (trimmedLine.startsWith("#if ")) {
         if (currentFunctionCall.length > 0) {
           throw new WgslTemplateGenerateError(
             `Preprocessor directive inside function call at line ${currentLine + 1}`,
@@ -477,7 +478,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         }
 
         // Check if there's a condition after #if
-        const condition = line.slice(4).trim();
+        const condition = trimmedLine.slice(4).trim();
         if (condition.length === 0) {
           throw new WgslTemplateGenerateError(
             `Empty condition in #if directive at line ${currentLine + 1}`,
@@ -486,7 +487,8 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
           );
         }
 
-        currentColumn = 4;
+        const leadingWhitespaceLength = line.length - trimmedLine.length;
+        currentColumn = leadingWhitespaceLength + 4; // Account for leading whitespace + "#if "
         preprocessIfStack.push(["if", currentParenthesesState, currentBracketState, null, null]);
         output("raw", "if (");
         currentPreProcessorExpression = [];
@@ -511,7 +513,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         generatorState.result.push(...currentPreProcessorExpression);
         currentPreProcessorExpression = null;
         output("raw", ") {\n");
-      } else if (line.startsWith("#elif ")) {
+      } else if (trimmedLine.startsWith("#elif ")) {
         if (
           preprocessIfStack.length === 0 ||
           (preprocessIfStack[preprocessIfStack.length - 1][0] !== "if" &&
@@ -552,7 +554,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         currentBracketState = preprocessIfStack[preprocessIfStack.length - 1][2]; // Reset bracket state to the initial state of the current block
 
         // Check if there's a condition after #elif
-        const condition = line.slice(6).trim();
+        const condition = trimmedLine.slice(6).trim();
         if (condition.length === 0) {
           throw new WgslTemplateGenerateError(
             `Empty condition in #elif directive at line ${currentLine + 1}`,
@@ -561,7 +563,8 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
           );
         }
 
-        currentColumn = 6;
+        const leadingWhitespaceLength = line.length - trimmedLine.length;
+        currentColumn = leadingWhitespaceLength + 6; // Account for leading whitespace + "#elif "
         preprocessIfStack[preprocessIfStack.length - 1][0] = "elif";
         output("raw", "} else if (");
         currentPreProcessorExpression = [];
@@ -586,7 +589,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         generatorState.result.push(...currentPreProcessorExpression);
         currentPreProcessorExpression = null;
         output("raw", ") {\n");
-      } else if (line.startsWith("#else")) {
+      } else if (trimmedLine.startsWith("#else")) {
         if (
           preprocessIfStack.length === 0 ||
           (preprocessIfStack[preprocessIfStack.length - 1][0] !== "if" &&
@@ -626,7 +629,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         currentParenthesesState = preprocessIfStack[preprocessIfStack.length - 1][1]; // Reset parentheses state to the initial state of the current block
         currentBracketState = preprocessIfStack[preprocessIfStack.length - 1][2]; // Reset bracket state to the initial state of the current block
 
-        if (line.substring(5).trim() !== "") {
+        if (trimmedLine.substring(5).trim() !== "") {
           throw new WgslTemplateGenerateError(
             `Unexpected content after #else at line ${currentLine + 1}`,
             "code-generation-failed",
@@ -635,7 +638,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         }
         preprocessIfStack[preprocessIfStack.length - 1][0] = "else";
         output("raw", "} else {\n");
-      } else if (line.startsWith("#endif")) {
+      } else if (trimmedLine.startsWith("#endif")) {
         if (preprocessIfStack.length === 0) {
           throw new WgslTemplateGenerateError(`#endif mismatch at line ${currentLine + 1}`, "code-generation-failed", {
             lineNumber: currentLine + 1,
@@ -667,7 +670,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
           );
         }
 
-        if (line.substring(6).trim() !== "") {
+        if (trimmedLine.substring(6).trim() !== "") {
           throw new WgslTemplateGenerateError(
             `Unexpected content after #endif at line ${currentLine + 1}`,
             "code-generation-failed",
@@ -677,7 +680,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         output("raw", "}\n");
         preprocessIfStack.pop();
       } else {
-        if (["#use", "#param", "#if", "#elif"].includes(line)) {
+        if (["#use", "#param", "#if", "#elif"].includes(trimmedLine)) {
           throw new WgslTemplateGenerateError(
             `Missing content after preprocessor directive at line ${currentLine + 1}`,
             "code-generation-failed",
@@ -686,7 +689,7 @@ function generateImpl(generatorState: GeneratorState, options: GenerateOptions)
         } else {
           // Handle unknown preprocessor directive
           throw new WgslTemplateGenerateError(
-            `Unknown preprocessor directive: ${line} at line ${currentLine + 1}`,
+            `Unknown preprocessor directive: ${trimmedLine} at line ${currentLine + 1}`,
             "code-generation-failed",
             { filePath: generatorState.filePath, lineNumber: currentLine + 1 }
           );

src/parser-impl.ts

@@ -91,7 +91,7 @@ function parsePreprocessorIncludeDirectives(includeStack: string[], parseState:
     const parsedLine = currentState.lines[lineNumber];
     const line = parsedLine.line;
     // Process each line and extract include directives
-    const includeMatch = line.match(/^#include\s+(.+)$/);
+    const includeMatch = line.match(/^\s*#include\s+(.+)$/);
     if (includeMatch) {
       const includeParam = includeMatch[1].trim();
       if (!(includeParam.startsWith('"') && includeParam.endsWith('"'))) {
@@ -154,10 +154,10 @@ function parseMacroDirectives(lines: ParsedLine[], fileName: string): ParsedLine
 
     // Check for malformed #define directives
     if (line.trim().startsWith("#define ")) {
-      const defineMatch = line.match(/^#define\s+([a-zA-Z_][a-zA-Z0-9_]*)\s+(.+)$/);
+      const defineMatch = line.match(/^\s*#define\s+([a-zA-Z_][a-zA-Z0-9_]*)\s+(.+)$/);
       if (!defineMatch) {
         // Check specific error cases
-        const emptyValueMatch = line.match(/^#define\s+([a-zA-Z_][a-zA-Z0-9_]*)\s*$/);
+        const emptyValueMatch = line.match(/^\s*#define\s+([a-zA-Z_][a-zA-Z0-9_]*)\s*$/);
         if (emptyValueMatch) {
           throw new WgslTemplateParseError(
             `Invalid macro definition in file ${fileName} at line ${
@@ -168,7 +168,7 @@ function parseMacroDirectives(lines: ParsedLine[], fileName: string): ParsedLine
           );
         }
 
-        const invalidNameMatch = line.match(/^#define\s+(\S+)(?:\s+(.+))?$/);
+        const invalidNameMatch = line.match(/^\s*#define\s+(\S+)(?:\s+(.+))?$/);
         if (invalidNameMatch) {
           throw new WgslTemplateParseError(
             `Invalid macro definition in file ${fileName} at line ${

test/testcases/.gitattributes

@@ -1,2 +1,2 @@
-# Preserve line endings for expectation files
-**/expected/
+# Preserve line endings for test expectation files
+**/expected/** text eol=lf

test/testcases/generator-if-space-prefix/test-config.json

@@ -0,0 +1,11 @@
+{
+  "type": "generator",
+  "description": "Test #if directive with space at the beginning of line",
+  "entries": {
+    "test.wgsl.template": {
+      "generators": {
+        "dynamic": {}
+      }
+    }
+  }
+}

test/testcases/generator-if-space-prefix/test.wgsl.template

@@ -0,0 +1,9 @@
+#param ENABLE_FEATURE
+
+fn test_function(value: f32) -> f32 {
+ #if ENABLE_FEATURE
+    return value * 2.0;
+ #else
+    return value;
+ #endif
+}

test/testcases/generator-if-space-prefix/test.wgsl.template.dynamic.gen

@@ -0,0 +1,7 @@
+emit("fn test_function(value: f32) -> f32 {\n");
+if (param["ENABLE_FEATURE"]) {
+emit("    return value * 2.0;\n");
+} else {
+emit("    return value;\n");
+}
+emit("}\n");

test/testcases/parser-include-space-prefix/constants.wgsl.template

@@ -0,0 +1 @@
+const PI: f32 = 3.14159;

test/testcases/parser-include-space-prefix/constants.wgsl.template.pass1

@@ -0,0 +1 @@
+const PI: f32 = 3.14159;

test/testcases/parser-include-space-prefix/main.wgsl.template

@@ -0,0 +1,8 @@
+// Test #include with space at beginning of line
+ #include "constants.wgsl.template"
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
+    let index = global_id.x;
+    let value = PI * f32(index);
+}

test/testcases/parser-include-space-prefix/main.wgsl.template.pass1

@@ -0,0 +1,9 @@
+
+const PI: f32 = 3.14159;
+
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
+    let index = global_id.x;
+    let value = PI * f32(index);
+}

test/testcases/parser-include-space-prefix/test-config.json

@@ -0,0 +1,4 @@
+{
+  "type": "parser",
+  "description": "Test #include directive with space at the beginning of line"
+}

test/testcases/parser-macro-space-prefix/main.wgsl.template

@@ -0,0 +1,15 @@
+// Test #define with space at beginning of line
+ #define PI 3.14159
+ #define MAX_SIZE 1024
+
+const pi_value = PI;
+const buffer_size = MAX_SIZE;
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
+    let index = global_id.x;
+    let area = PI * f32(index) * f32(index);
+    if (index < MAX_SIZE) {
+        // Process within bounds
+    }
+}

test/testcases/parser-macro-space-prefix/main.wgsl.template.pass1

@@ -0,0 +1,15 @@
+
+
+
+
+const pi_value = 3.14159;
+const buffer_size = 1024;
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
+    let index = global_id.x;
+    let area = 3.14159 * f32(index) * f32(index);
+    if (index < 1024) {
+
+    }
+}

test/testcases/parser-macro-space-prefix/test-config.json

@@ -0,0 +1,4 @@
+{
+  "type": "parser",
+  "description": "Test #define directive with space at the beginning of line"
+}