Remove the embedded source to avoid self-matching in slang-test (#8305)

When `SIMPLE` type test is used with `-g[1-3]` option, the filecheck
pattern will most likely to match to the string itself on the embedded
source code rather than match to the emitted spirv-asm code.

This commit avoids the problem by removing the embedded source code.

This commit also provides an option to keep the embedded source code,
`-preserve-embedded-source`.

The source code removal is happening in two steps:
1. iterate all output lines and find SPIRV-ASM in the following pattern:
`%N = OpExtInst %void %M DebugSource %fileId %sourceId`. And then, store
the "%sourceId" value to identify which SPIRV instructions are for the
embedded source code.
2. iterate all output lines again to find the `%sourceId = OpString
"...."` and replace the whole string with the following string, ``` %1 =
OpString "// slang-test removed the embedded source // Use
`-preserve-embedded-source` to keep it explicitly " ```

This change revealed problems in the existing tests:
- tests/bugs/spirv-debug-info.slang : The expected text was missing and
it had to be added. The file also had Carrage-Return character on all
lines and the pre-commit git hook removed them.
- tests/spirv/debug-info.slang : the expected keyword DebugValue had to
change to DebugDeclare, because that's what we get with ToT.
- tests/spirv/debug-value-dynamic-index.slang : This test is currently
failing, and it will pass once DebugLocalVariable instruction missing
for parameter of the entry point function #7693 is resolved.

---------

Co-authored-by: slangbot <ellieh+slangbot@nvidia.com>

1 files changed, 105 insertions, 2 deletions

diff --git a/tools/slang-test/slang-test-main.cpp b/tools/slang-test/slang-test-main.cpp
index 3f707b5e5..6c0de13ec 100644
--- a/tools/slang-test/slang-test-main.cpp
+++ b/tools/slang-test/slang-test-main.cpp
@@ -54,6 +54,9 @@ SLANG_RHI_EXPORT_AGILITY_SDK
 
 using namespace Slang;
 
+// Constants for slang-test specific options
+static const char* kPreserveEmbeddedSourceOption = "-preserve-embedded-source";
+
 // Options for a particular test
 struct TestOptions
 {
@@ -1531,7 +1534,94 @@ ToolReturnCode spawnAndWait(
     return getReturnCode(outExeRes);
 }
 
-String getOutput(const ExecuteResult& exeRes)
+// Remove embedded source code from SPIR-V assembly output to prevent filecheck from matching
+// against embedded source instead of actual SPIR-V instructions
+String removeEmbeddedSourceFromSPIRV(const String& spirvOutput)
+{
+    StringBuilder filteredOutput;
+    List<UnownedStringSlice> lines;
+    StringUtil::calcLines(spirvOutput.getUnownedSlice(), lines);
+
+    if (spirvOutput.endsWith("\n"))
+    {
+        // The last empty line should be removed,
+        // because `StringUtil::calcLines()` turns "A\nB\n" into three lines; not two.
+        SLANG_ASSERT(lines[lines.getCount() - 1] == "");
+        lines.setCount(lines.getCount() - 1);
+    }
+
+    // First pass: Find OpString IDs that are referenced by DebugSource
+    List<String> sourceStringIds;
+    for (const auto& line : lines)
+    {
+        UnownedStringSlice trimmedLine = line.trim();
+
+        if (trimmedLine.indexOf(UnownedStringSlice(" DebugSource ")) == Index(-1))
+            continue;
+
+        // Extract the last parameter which is the source string ID
+        // Pattern: %4 = OpExtInst %void %2 DebugSource %5 %1
+        List<UnownedStringSlice> tokens;
+        StringUtil::split(trimmedLine, ' ', tokens);
+
+        // The last token should be the source string ID
+        UnownedStringSlice lastToken = tokens.getLast();
+        if (lastToken.startsWith(UnownedStringSlice("%")))
+        {
+            sourceStringIds.add(String(lastToken));
+        }
+    }
+
+    // Second pass: Process embedded source strings to replace content with informative message
+    bool insideSourceString = false;
+    for (const auto& line : lines)
+    {
+        UnownedStringSlice trimmedLine = line.trim();
+
+        if (!insideSourceString)
+        {
+            Index equalPos = trimmedLine.indexOf(UnownedStringSlice(" = OpString"));
+            if (equalPos != Index(-1) && trimmedLine.startsWith(UnownedStringSlice("%")))
+            {
+                String currentStringId = String(trimmedLine.head(equalPos));
+                if (sourceStringIds.contains(currentStringId))
+                {
+                    insideSourceString = true;
+                    Index quotePos = line.indexOf('\"');
+                    if (quotePos != Index(-1))
+                    {
+                        filteredOutput.append(String(line.head(quotePos + 1)));
+                        filteredOutput.append("// slang-test removed the embedded source\n");
+                        filteredOutput.append("// Use `");
+                        filteredOutput.append(kPreserveEmbeddedSourceOption);
+                        filteredOutput.append("` to keep it explicitly\n\"\n");
+                    }
+                    continue;
+                }
+            }
+        }
+
+        if (insideSourceString)
+        {
+            if (trimmedLine.endsWith("\"") &&
+                (trimmedLine.getLength() < 2 || trimmedLine[trimmedLine.getLength() - 2] != '\\'))
+            {
+                insideSourceString = false;
+            }
+
+            // skip the embedded source lines
+            continue;
+        }
+
+        // Add this line to the filtered output
+        filteredOutput.append(line);
+        filteredOutput.append("\n");
+    }
+
+    return filteredOutput.produceString();
+}
+
+String getOutput(const ExecuteResult& exeRes, bool removeEmbeddedSource = false)
 {
     ExecuteResult::ResultCode resultCode = exeRes.resultCode;
 
@@ -1539,6 +1629,12 @@ String getOutput(const ExecuteResult& exeRes)
     String standardError = exeRes.standardError;
     String debugLayer = exeRes.debugLayer;
 
+    // Apply embedded source removal to standard output if requested
+    if (removeEmbeddedSource)
+    {
+        standardOuptut = removeEmbeddedSourceFromSPIRV(standardOuptut);
+    }
+
     // We construct a single output string that captures the results
     StringBuilder actualOutputBuilder;
     actualOutputBuilder.append("result code = ");
@@ -2325,6 +2421,9 @@ TestResult runSimpleTest(TestContext* context, TestInput& input)
 
     for (auto arg : input.testOptions->args)
     {
+        // Filter out slang-test specific options that shouldn't be passed to slangc
+        if (arg == kPreserveEmbeddedSourceOption)
+            continue;
         cmdLine.addArg(arg);
     }
 
@@ -2366,7 +2465,11 @@ TestResult runSimpleTest(TestContext* context, TestInput& input)
         exeRes = runExeRes;
     }
 
-    String actualOutput = getOutput(exeRes);
+    bool needToRemoveEmbeddedSource =
+        ((target == SLANG_SPIRV || target == SLANG_SPIRV_ASM) &&
+         input.testOptions->args.indexOf(kPreserveEmbeddedSourceOption) == Index(-1));
+
+    String actualOutput = getOutput(exeRes, needToRemoveEmbeddedSource);
 
     return _validateOutput(
         context,