Fix a crash when search for files. (#5818)

Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

source/core/slang-string-util.cpp

@@ -461,7 +461,7 @@ String StringUtil::replaceAll(
     StringBuilder builder;
     for (Index i = 0; i < text.getLength();)
     {
-        if (i + subStr.getLength() >= text.getLength())
+        if (i + subStr.getLength() > text.getLength())
         {
             builder.append(text.subString(i, text.getLength() - i));
             break;

source/slang/slang.cpp

@@ -4257,7 +4257,7 @@ SourceFile* Linkage::findFile(Name* name, SourceLoc loc, IncludeSystem& outInclu
         // Next, try to find the file of the given name,
         // using our ordinary include-handling logic.
 
-        auto searchDirs = getSearchDirectories();
+        auto& searchDirs = getSearchDirectories();
         outIncludeSystem = IncludeSystem(&searchDirs, getFileSystemExt(), getSourceManager());
 
         // Get the original path info

tests/language-feature/modules/gh-5799/Common/Common.slang

@@ -0,0 +1,3 @@
+module Common;
+
+__include Common.Test;

tests/language-feature/modules/gh-5799/Common/Test.slang

@@ -0,0 +1,8 @@
+//#pragma once
+#include "Simple.h"
+//
+//#ifndef HOST_CODE
+//implementing Common;
+//#endif
+implementing Common;
+

tests/language-feature/modules/gh-5799/HelloTriangleFS.slang

@@ -0,0 +1,37 @@
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -I $dirname
+
+//CHECK: OpEntryPoint
+
+// shaders.slang
+
+//
+// This file provides a simple vertex and fragment shader that can be compiled
+// using Slang. This code should also be valid as HLSL, and thus it does not
+// use any of the new language features supported by Slang.
+//
+
+import Scene.Scene;
+
+// Output of the vertex shader, and input to the fragment shader.
+struct CoarseVertex
+{
+    float3 color;
+};
+
+// Output of the fragment shader
+struct Fragment
+{
+    float4 color;
+};
+
+
+// Fragment Shader
+
+[shader("fragment")]
+float4 main(
+    CoarseVertex coarseVertex : CoarseVertex) : SV_Target
+{
+    float3 fragColor = coarseVertex.color;
+
+    return float4(fragColor, 1.0);
+}

tests/language-feature/modules/gh-5799/Scene/Scene.slang

@@ -0,0 +1,3 @@
+module Scene;
+import Common.Common;
+

tools/slang-test/slang-test-main.cpp

@@ -524,6 +524,17 @@ static SlangResult _extractCommand(const char** ioCursor, UnownedStringSlice& ou
     }
 }
 
+static void applyMacroSubstitution(String filePath, TestDetails& details)
+{
+    for (auto& arg : details.options.args)
+    {
+        arg = StringUtil::replaceAll(
+            arg.getUnownedSlice(),
+            toSlice("$dirname"),
+            Path::getParentDirectory(filePath).getUnownedSlice());
+    }
+}
+
 // Try to read command-line options from the test file itself
 static SlangResult _gatherTestsForFile(
     TestCategorySet* categorySet,
@@ -597,6 +608,7 @@ static SlangResult _gatherTestsForFile(
         if (command == "TEST")
         {
             SLANG_RETURN_ON_FAIL(_gatherTestOptions(categorySet, &cursor, testDetails.options));
+            applyMacroSubstitution(filePath, testDetails);
 
             // See if the type of test needs certain APIs available
             const RenderApiFlags testRequiredApis =
@@ -611,6 +623,7 @@ static SlangResult _gatherTestsForFile(
         else if (command == "DIAGNOSTIC_TEST")
         {
             SLANG_RETURN_ON_FAIL(_gatherTestOptions(categorySet, &cursor, testDetails.options));
+            applyMacroSubstitution(filePath, testDetails);
 
             // Apply the file wide options
             _combineOptions(categorySet, fileOptions, testDetails.options);