Language server fixes and improvements (#2304)

* Language server: Inlay hints.

* Signature help for base exprs that is not a declref.

* Fix checking of jvp operator.

* Fix.

* Add clang-format based auto formatting.

* Fix clang error.

* Fix clang-format discovery logic.

* Fine tune auto formatting and completion experience.

* Update macos workflow.

* Fixes to configurations.

* Fix parser recovery to trigger completion for index exprs.

* Typo fix.

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 213 insertions, 0 deletions

diff --git a/source/slang/slang-language-server-auto-format.cpp b/source/slang/slang-language-server-auto-format.cpp
new file mode 100644
index 000000000..8d31c44c6
--- /dev/null
+++ b/source/slang/slang-language-server-auto-format.cpp
@@ -0,0 +1,213 @@
+#include "slang-language-server-auto-format.h"
+#include "../core/slang-char-util.h"
+#include "../compiler-core/slang-lexer.h"
+
+namespace Slang
+{
+
+String findClangFormatTool()
+{
+    String processName = String("clang-format") + String(Process::getExecutableSuffix());
+    if (File::exists(processName))
+        return processName;
+    RefPtr<Process> proc;
+    CommandLine cmdLine;
+    cmdLine.setExecutableLocation(ExecutableLocation(processName));
+    if (Process::create(cmdLine, 0, proc) == SLANG_OK)
+    {
+        auto inStream = proc->getStream(StdStreamType::In);
+        if (inStream) inStream->close();
+        proc->kill(0);
+        return processName;
+    }
+    auto fileName =
+        Slang::SharedLibraryUtils::getSharedLibraryFileName((void*)slang_createGlobalSession);
+    auto dirName = Slang::Path::getParentDirectory(fileName);
+    auto localProcess = Path::combine(dirName, processName);
+    if (File::exists(localProcess))
+        return localProcess;
+
+    Index vsCodeLoc = dirName.indexOf(".vscode");
+    if (vsCodeLoc != -1)
+    {
+        // If we still cannot find clang-format, try to use the clang-format bundled with VSCode's C++ extension.
+        String vsCodeExtDir = dirName.subString(0, vsCodeLoc + 7);
+        vsCodeExtDir = Path::combine(vsCodeExtDir, "extensions");
+        struct CallbackContext
+        {
+            String foundPath;
+            String parentDir;
+            String processName;
+        } callbackContext;
+        callbackContext.processName = processName;
+        callbackContext.parentDir = vsCodeExtDir;
+        OSFileSystem::getExtSingleton()->enumeratePathContents(vsCodeExtDir.getBuffer(), [](SlangPathType /*pathType*/, const char* name, void* userData)
+        {
+            CallbackContext* context = (CallbackContext*)userData;
+            if (UnownedStringSlice(name).indexOf(UnownedStringSlice("ms-vscode.cpptools-")) != -1)
+            {
+                String candidateFileName = Path::combine(Path::combine(context->parentDir, name, "LLVM"), "bin", context->processName);
+                if (File::exists(candidateFileName))
+                    context->foundPath = candidateFileName;
+            }
+        }, & callbackContext);
+        if (callbackContext.foundPath.getLength())
+            return callbackContext.foundPath;
+    }
+    return String();
+}
+
+void translateXmlEscape(StringBuilder& sb, UnownedStringSlice text)
+{
+    if (text.getLength() == 0)
+        return;
+    if (text[0] == '#')
+    {
+        Int charVal = 0;
+        StringUtil::parseInt(text.tail(1), charVal);
+        if (charVal != 0)
+            sb.appendChar((char)charVal);
+    }
+    else if (text == "lt")
+    {
+        sb.appendChar('<');
+    }
+    else if (text == "gt")
+    {
+        sb.appendChar('>');
+    }
+    else if (text == "amp")
+    {
+        sb.appendChar('&');
+    }
+    else if (text == "apos")
+    {
+        sb.appendChar('\'');
+    }
+    else if (text == "quot")
+    {
+        sb.appendChar('\"');
+    }
+}
+
+String parseXmlText(UnownedStringSlice text)
+{
+    StringBuilder sb;
+    Index pos = 0;
+    for (; pos < text.getLength();)
+    {
+        if (text[pos] == '&')
+        {
+            pos++;
+            Index endPos = pos;
+            while (endPos < text.getLength() && text[endPos] != ';')
+                endPos++;
+            auto escapedToken = text.subString(pos, endPos - pos);
+            pos = endPos + 1;
+            translateXmlEscape(sb, escapedToken);
+        }
+        else
+        {
+            sb.appendChar(text[pos]);
+            pos++;
+        }
+    }
+    return sb.ProduceString();
+}
+
+List<Edit> formatSource(UnownedStringSlice text, Index lineStart, Index lineEnd, Index cursorOffset, const FormatOptions& options)
+{
+    List<Edit> edits;
+
+    String clangProcessName = options.clangFormatLocation;
+    CommandLine cmdLine;
+    cmdLine.setExecutableLocation(ExecutableLocation(clangProcessName));
+    cmdLine.addArg("--assume-filename=source.cs");
+    if (cursorOffset != -1)
+    {
+        cmdLine.addArg("--cursor=" + String(cursorOffset));
+    }
+    if (lineStart != -1)
+    {
+        cmdLine.addArg("--lines=" + String(lineStart) + ":" + String(lineEnd + 1));
+    }
+    cmdLine.addArg("--output-replacements-xml");
+    if (options.style.getLength())
+    {
+        cmdLine.addArg("-style");
+        cmdLine.addArg(options.style);
+    }
+    RefPtr<Process> proc;
+    if (SLANG_FAILED(Process::create(cmdLine, 0, proc)))
+        return edits;
+
+    auto inStream = proc->getStream(StdStreamType::In);
+    inStream->write(text.begin(), text.getLength());
+    char terminator = '\0';
+    inStream->write(&terminator, 1);
+    inStream->flush();
+    inStream->close();
+    ExecuteResult result;
+    ProcessUtil::readUntilTermination(proc, result);
+
+    /*
+    Example result of clang-format:
+
+    <?xml version='1.0'?>
+    <replacements xml:space='preserve' incomplete_format='false'>
+    <replacement offset='26' length='2'>&#13;&#10;  </replacement>
+    </replacements>
+    */
+
+    // Adhoc parsing of clang-format's result.
+    List<UnownedStringSlice> lines;
+    auto offsetStr = UnownedStringSlice("offset=");
+    auto lengthStr = UnownedStringSlice("length=");
+    auto endStr = UnownedStringSlice("</replacement>");
+    auto replacementStr = UnownedStringSlice("<replacement ");
+    StringUtil::calcLines(result.standardOutput.getUnownedSlice(), lines);
+    for (auto line : lines)
+    {
+        line = line.trim();
+        if (!line.startsWith(replacementStr))
+            continue;
+        line = line.tail(replacementStr.getLength());
+        Index pos = line.indexOf(offsetStr);
+        if (pos == -1)
+            continue;
+        pos += offsetStr.getLength();
+        if (pos < line.getLength() && line[pos] == '\'')
+            pos++;
+        Edit edt;
+        edt.offset = StringUtil::parseIntAndAdvancePos(line, pos);
+        pos = line.indexOf(lengthStr);
+        if (pos == -1)
+            continue;
+        pos += lengthStr.getLength();
+        if (pos < line.getLength() && line[pos] == '\'')
+            pos++;
+        edt.length = StringUtil::parseIntAndAdvancePos(line, pos);
+        line = line.tail(pos);
+        pos = line.indexOf('>');
+        if (pos == -1)
+            continue;
+        line = line.tail(pos + 1);
+        Index endPos = line.indexOf(endStr);
+        if (endPos == -1)
+            continue;
+        line = line.head(endPos);
+        edt.text = parseXmlText(line);
+        // For on-type formatting, don't make any changes beyond the current cursor position.
+        if (cursorOffset != -1 && edt.offset >= cursorOffset)
+            break;
+        // Never allow clang-format to put the semicolon after `}` in its own line.
+        if (edt.offset < text.getLength() && edt.length == 0 && text[edt.offset] == ';' && edt.offset >0 && text[edt.offset - 1] == '}')
+            continue;
+
+        edits.add(edt);
+    }
+    return edits;
+}
+
+
+} // namespace Slang