[llvm][mustache] Simplify debug logging #159193

ilovepi · 2025-09-16T22:08:33Z

No description provided.

ilovepi · 2025-09-16T22:08:48Z

This stack of pull requests is managed by Graphite. Learn more about stacking.

llvmbot · 2025-09-16T22:09:06Z

@llvm/pr-subscribers-llvm-support

Author: Paul Kirth (ilovepi)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/159193.diff

1 Files Affected:

(modified) llvm/lib/Support/Mustache.cpp (+64-55)

diff --git a/llvm/lib/Support/Mustache.cpp b/llvm/lib/Support/Mustache.cpp
index e084e379312ef..6dab658ea535d 100644
--- a/llvm/lib/Support/Mustache.cpp
+++ b/llvm/lib/Support/Mustache.cpp
@@ -187,14 +187,14 @@ class ASTNode {
   void render(const llvm::json::Value &Data, MustacheOutputStream &OS);
 
 private:
-  void renderLambdas(const llvm::json::Value &Contexts, MustacheOutputStream &OS,
-                     Lambda &L);
+  void renderLambdas(const llvm::json::Value &Contexts,
+                     MustacheOutputStream &OS, Lambda &L);
 
   void renderSectionLambdas(const llvm::json::Value &Contexts,
                             MustacheOutputStream &OS, SectionLambda &L);
 
-  void renderPartial(const llvm::json::Value &Contexts, MustacheOutputStream &OS,
-                     ASTNode *Partial);
+  void renderPartial(const llvm::json::Value &Contexts,
+                     MustacheOutputStream &OS, ASTNode *Partial);
 
   void renderChild(const llvm::json::Value &Context, MustacheOutputStream &OS);
 
@@ -204,9 +204,11 @@ class ASTNode {
   void renderText(MustacheOutputStream &OS);
   void renderPartial(const json::Value &CurrentCtx, MustacheOutputStream &OS);
   void renderVariable(const json::Value &CurrentCtx, MustacheOutputStream &OS);
-  void renderUnescapeVariable(const json::Value &CurrentCtx, MustacheOutputStream &OS);
+  void renderUnescapeVariable(const json::Value &CurrentCtx,
+                              MustacheOutputStream &OS);
   void renderSection(const json::Value &CurrentCtx, MustacheOutputStream &OS);
-  void renderInvertSection(const json::Value &CurrentCtx, MustacheOutputStream &OS);
+  void renderInvertSection(const json::Value &CurrentCtx,
+                           MustacheOutputStream &OS);
 
   MustacheContext &Ctx;
   Type Ty;
@@ -330,6 +332,36 @@ struct Tag {
   size_t StartPosition = StringRef::npos;
 };
 
+static const char *tagKindToString(Tag::Kind K) {
+  switch (K) {
+  case Tag::Kind::None:
+    return "None";
+  case Tag::Kind::Normal:
+    return "Normal";
+  case Tag::Kind::Triple:
+    return "Triple";
+  }
+  llvm_unreachable("Unknown Tag::Kind");
+}
+
+static const char *jsonKindToString(json::Value::Kind K) {
+  switch (K) {
+  case json::Value::Kind::Null:
+    return "JSON_KIND_NULL";
+  case json::Value::Kind::Boolean:
+    return "JSON_KIND_BOOLEAN";
+  case json::Value::Kind::Number:
+    return "JSON_KIND_NUMBER";
+  case json::Value::Kind::String:
+    return "JSON_KIND_STRING";
+  case json::Value::Kind::Array:
+    return "JSON_KIND_ARRAY";
+  case json::Value::Kind::Object:
+    return "JSON_KIND_OBJECT";
+  }
+  llvm_unreachable("Unknown json::Value::Kind");
+}
+
 static Tag findNextTag(StringRef Template, size_t StartPos, StringRef Open,
                        StringRef Close) {
   const StringLiteral TripleOpen("{{{");
@@ -374,11 +406,10 @@ static Tag findNextTag(StringRef Template, size_t StartPos, StringRef Open,
 
 static std::optional<std::pair<StringRef, StringRef>>
 processTag(const Tag &T, SmallVectorImpl<Token> &Tokens) {
-  LLVM_DEBUG(dbgs() << "  Found tag: \"" << T.FullMatch << "\", Content: \""
-                    << T.Content << "\"\n");
+  LLVM_DEBUG(dbgs() << "[Tag] " << T.FullMatch << ", Content: " << T.Content
+                    << ", Kind: " << tagKindToString(T.TagKind) << "\n");
   if (T.TagKind == Tag::Kind::Triple) {
     Tokens.emplace_back(T.FullMatch.str(), "&" + T.Content.str(), '&');
-    LLVM_DEBUG(dbgs() << "  Created UnescapeVariable token.\n");
     return std::nullopt;
   }
   StringRef Interpolated = T.Content;
@@ -386,7 +417,6 @@ processTag(const Tag &T, SmallVectorImpl<Token> &Tokens) {
   if (!Interpolated.trim().starts_with("=")) {
     char Front = Interpolated.empty() ? ' ' : Interpolated.trim().front();
     Tokens.emplace_back(RawBody, Interpolated.str(), Front);
-    LLVM_DEBUG(dbgs() << "  Created tag token of type '" << Front << "'\n");
     return std::nullopt;
   }
   Tokens.emplace_back(RawBody, Interpolated.str(), '=');
@@ -396,8 +426,8 @@ processTag(const Tag &T, SmallVectorImpl<Token> &Tokens) {
   DelimSpec = DelimSpec.trim();
 
   auto [NewOpen, NewClose] = DelimSpec.split(' ');
-  LLVM_DEBUG(dbgs() << "  Found Set Delimiter tag. NewOpen='" << NewOpen
-                    << "', NewClose='" << NewClose << "'\n");
+  LLVM_DEBUG(dbgs() << "[Set Delimiter] NewOpen: " << NewOpen
+                    << ", NewClose: " << NewClose << "\n");
   return std::make_pair(NewOpen, NewClose);
 }
 
@@ -406,22 +436,20 @@ processTag(const Tag &T, SmallVectorImpl<Token> &Tokens) {
 // but we don't support that here. An unescape variable
 // is represented only by {{& variable}}.
 static SmallVector<Token> tokenize(StringRef Template) {
-  LLVM_DEBUG(dbgs() << "Tokenizing template: \"" << Template << "\"\n");
+  LLVM_DEBUG(dbgs() << "[Tokenize Template] \"" << Template << "\"\n");
   SmallVector<Token> Tokens;
   SmallString<8> Open("{{");
   SmallString<8> Close("}}");
   size_t Start = 0;
 
   while (Start < Template.size()) {
-    LLVM_DEBUG(dbgs() << "Loop start. Start=" << Start << ", Open='" << Open
+    LLVM_DEBUG(dbgs() << "[Tokenize Loop] Start=" << Start << ", Open='" << Open
                       << "', Close='" << Close << "'\n");
     Tag T = findNextTag(Template, Start, Open, Close);
 
     if (T.TagKind == Tag::Kind::None) {
       // No more tags, the rest is text.
       Tokens.emplace_back(Template.substr(Start).str());
-      LLVM_DEBUG(dbgs() << "  No more tags. Created final Text token: \"" 
-                        << Template.substr(Start) << "\"\n");
       break;
     }
 
@@ -429,7 +457,6 @@ static SmallVector<Token> tokenize(StringRef Template) {
     if (T.StartPosition > Start) {
       StringRef Text = Template.substr(Start, T.StartPosition - Start);
       Tokens.emplace_back(Text.str());
-      LLVM_DEBUG(dbgs() << "  Created Text token: \"" << Text << "\"\n");
     }
 
     if (auto NewDelims = processTag(T, Tokens)) {
@@ -480,15 +507,13 @@ static SmallVector<Token> tokenize(StringRef Template) {
     if ((!HasTextBehind && !HasTextAhead) || (!HasTextBehind && Idx == LastIdx))
       stripTokenBefore(Tokens, Idx, CurrentToken, CurrentType);
   }
-  LLVM_DEBUG(dbgs() << "Tokenizing finished.\n");
   return Tokens;
 }
 
 // Custom stream to escape strings.
 class EscapeStringStream : public MustacheOutputStream {
 public:
-  explicit EscapeStringStream(raw_ostream &WrappedStream,
-                              EscapeMap &Escape)
+  explicit EscapeStringStream(raw_ostream &WrappedStream, EscapeMap &Escape)
       : Escape(Escape), WrappedStream(WrappedStream) {
     SetUnbuffered();
   }
@@ -532,7 +557,7 @@ class AddIndentationStringStream : public MustacheOutputStream {
     Indent.resize(Indentation, ' ');
 
     for (char C : Data) {
-      LLVM_DEBUG(dbgs() << "IndentationStream: NeedsIndent=" << NeedsIndent
+      LLVM_DEBUG(dbgs() << "[IndentationStream] NeedsIndent=" << NeedsIndent
                         << ", C='" << C << "', Indentation=" << Indentation
                         << "\n");
       if (NeedsIndent && C != '\n') {
@@ -641,7 +666,8 @@ void Parser::parseMustache(ASTNode *Parent) {
   }
 }
 static void toMustacheString(const json::Value &Data, raw_ostream &OS) {
-  LLVM_DEBUG(dbgs() << "toMustacheString: kind=" << (int)Data.kind() << "\n");
+  LLVM_DEBUG(dbgs() << "[To Mustache String] Kind: " << jsonKindToString(Data.kind())
+                    << ", Data: " << Data << "\n");
   switch (Data.kind()) {
   case json::Value::Null:
     return;
@@ -654,7 +680,6 @@ static void toMustacheString(const json::Value &Data, raw_ostream &OS) {
   }
   case json::Value::String: {
     auto Str = *Data.getAsString();
-    LLVM_DEBUG(dbgs() << "  --> writing string: \"" << Str << "\"\n");
     OS << Str.str();
     return;
   }
@@ -674,21 +699,24 @@ static void toMustacheString(const json::Value &Data, raw_ostream &OS) {
   }
 }
 
-void ASTNode::renderRoot(const json::Value &CurrentCtx, MustacheOutputStream &OS) {
+void ASTNode::renderRoot(const json::Value &CurrentCtx,
+                         MustacheOutputStream &OS) {
   renderChild(CurrentCtx, OS);
 }
 
 void ASTNode::renderText(MustacheOutputStream &OS) { OS << Body; }
 
-void ASTNode::renderPartial(const json::Value &CurrentCtx, MustacheOutputStream &OS) {
-  LLVM_DEBUG(dbgs() << "renderPartial: Accessor=" << AccessorValue[0]
+void ASTNode::renderPartial(const json::Value &CurrentCtx,
+                            MustacheOutputStream &OS) {
+  LLVM_DEBUG(dbgs() << "[Render Partial] Accessor=" << AccessorValue[0]
                     << ", Indentation=" << Indentation << "\n");
   auto Partial = Ctx.Partials.find(AccessorValue[0]);
   if (Partial != Ctx.Partials.end())
     renderPartial(CurrentCtx, OS, Partial->getValue().get());
 }
 
-void ASTNode::renderVariable(const json::Value &CurrentCtx, MustacheOutputStream &OS) {
+void ASTNode::renderVariable(const json::Value &CurrentCtx,
+                             MustacheOutputStream &OS) {
   auto Lambda = Ctx.Lambdas.find(AccessorValue[0]);
   if (Lambda != Ctx.Lambdas.end()) {
     renderLambdas(CurrentCtx, OS, Lambda->getValue());
@@ -700,13 +728,12 @@ void ASTNode::renderVariable(const json::Value &CurrentCtx, MustacheOutputStream
 
 void ASTNode::renderUnescapeVariable(const json::Value &CurrentCtx,
                                      MustacheOutputStream &OS) {
-  LLVM_DEBUG(dbgs() << "renderUnescapeVariable: Accessor=" << AccessorValue[0]
+  LLVM_DEBUG(dbgs() << "[Render UnescapeVariable] Accessor=" << AccessorValue[0]
                     << "\n");
   auto Lambda = Ctx.Lambdas.find(AccessorValue[0]);
   if (Lambda != Ctx.Lambdas.end()) {
     renderLambdas(CurrentCtx, OS, Lambda->getValue());
   } else if (const json::Value *ContextPtr = findContext()) {
-    LLVM_DEBUG(dbgs() << "  --> Found context value, writing to stream.\n");
     OS.suspendIndentation();
     toMustacheString(*ContextPtr, OS);
     OS.resumeIndentation();
@@ -714,7 +741,7 @@ void ASTNode::renderUnescapeVariable(const json::Value &CurrentCtx,
 }
 
 void ASTNode::renderSection(const json::Value &CurrentCtx,
-                              MustacheOutputStream &OS) {
+                            MustacheOutputStream &OS) {
   auto SectionLambda = Ctx.SectionLambdas.find(AccessorValue[0]);
   if (SectionLambda != Ctx.SectionLambdas.end()) {
     renderSectionLambdas(CurrentCtx, OS, SectionLambda->getValue());
@@ -776,8 +803,6 @@ void ASTNode::render(const llvm::json::Value &Data, MustacheOutputStream &OS) {
 }
 
 const json::Value *ASTNode::findContext() {
-  LLVM_DEBUG(dbgs() << "findContext: AccessorValue[0]=" << AccessorValue[0]
-                    << "\n");
   // The mustache spec allows for dot notation to access nested values
   // a single dot refers to the current context.
   // We attempt to find the JSON context in the current node, if it is not
@@ -792,24 +817,12 @@ const json::Value *ASTNode::findContext() {
   StringRef CurrentAccessor = AccessorValue[0];
   ASTNode *CurrentParent = Parent;
 
-  LLVM_DEBUG(dbgs() << "findContext: ParentContext: ";
-             if (ParentContext) ParentContext->print(dbgs());
-             else dbgs() << "nullptr";
-             dbgs() << "\n");
-
   while (!CurrentContext || !CurrentContext->get(CurrentAccessor)) {
-    LLVM_DEBUG(dbgs() << "findContext: climbing parent\n");
     if (CurrentParent->Ty != Root) {
       CurrentContext = CurrentParent->ParentContext->getAsObject();
       CurrentParent = CurrentParent->Parent;
-      LLVM_DEBUG(dbgs() << "findContext: new ParentContext: ";
-                 if (CurrentParent->ParentContext)
-                   CurrentParent->ParentContext->print(dbgs());
-                 else dbgs() << "nullptr";
-                 dbgs() << "\n");
       continue;
     }
-    LLVM_DEBUG(dbgs() << "findContext: reached root, not found\n");
     return nullptr;
   }
   const json::Value *Context = nullptr;
@@ -825,28 +838,24 @@ const json::Value *ASTNode::findContext() {
       Context = CurrentValue;
     }
   }
-  LLVM_DEBUG(dbgs() << "findContext: found value: ";
-             if (Context) Context->print(dbgs());
-             else dbgs() << "nullptr";
-             dbgs() << "\n");
   return Context;
 }
 
-void ASTNode::renderChild(const json::Value &Contexts, MustacheOutputStream &OS) {
+void ASTNode::renderChild(const json::Value &Contexts,
+                          MustacheOutputStream &OS) {
   for (AstPtr &Child : Children)
     Child->render(Contexts, OS);
 }
 
-void ASTNode::renderPartial(const json::Value &Contexts, MustacheOutputStream &OS,
-                            ASTNode *Partial) {
-  LLVM_DEBUG(dbgs() << "renderPartial (helper): Indentation=" << Indentation
-                    << "\n");
+void ASTNode::renderPartial(const json::Value &Contexts,
+                            MustacheOutputStream &OS, ASTNode *Partial) {
+  LLVM_DEBUG(dbgs() << "[Render Partial Indentation] " << Indentation << "\n");
   AddIndentationStringStream IS(OS, Indentation);
   Partial->render(Contexts, IS);
 }
 
-void ASTNode::renderLambdas(const json::Value &Contexts, MustacheOutputStream &OS,
-                            Lambda &L) {
+void ASTNode::renderLambdas(const json::Value &Contexts,
+                            MustacheOutputStream &OS, Lambda &L) {
   json::Value LambdaResult = L();
   std::string LambdaStr;
   raw_string_ostream Output(LambdaStr);

github-actions · 2025-09-16T22:12:19Z

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff origin/main HEAD --extensions cpp -- llvm/lib/Support/Mustache.cpp

⚠️
The reproduction instructions above might return results for more than one PR
in a stack if you are using a stacked PR workflow. You can limit the results by
changing origin/main to the base branch/commit you want to compare against.
⚠️

View the diff from clang-format here.

diff --git a/llvm/lib/Support/Mustache.cpp b/llvm/lib/Support/Mustache.cpp
index 178f97030..0098b1d39 100644
--- a/llvm/lib/Support/Mustache.cpp
+++ b/llvm/lib/Support/Mustache.cpp
@@ -864,7 +864,8 @@ void ASTNode::renderChild(const json::Value &Contexts,
 
 void ASTNode::renderPartial(const json::Value &Contexts,
                             MustacheOutputStream &OS, ASTNode *Partial) {
-  LLVM_DEBUG(dbgs() << "[Render Partial Indentation] Indentation: " << Indentation << "\n");
+  LLVM_DEBUG(dbgs() << "[Render Partial Indentation] Indentation: "
+                    << Indentation << "\n");
   AddIndentationStringStream IS(OS, Indentation);
   Partial->render(Contexts, IS);
 }

petrhosek · 2025-09-30T06:35:47Z

llvm/lib/Support/Mustache.cpp


    for (char C : Data) {
-      LLVM_DEBUG(dbgs() << "IndentationStream: NeedsIndent=" << NeedsIndent
+      LLVM_DEBUG(dbgs() << "[IndentationStream] NeedsIndent=" << NeedsIndent


It's not clear to me where we use FooBar and when we use Foo Bar since there doesn't seem to be much consistency.

I think this one is the odd one out. good catch. let me shore up the rest.

mikaelholmen · 2025-10-01T06:11:10Z

llvm/lib/Support/Mustache.cpp

  size_t StartPosition = StringRef::npos;
 };

+static const char *tagKindToString(Tag::Kind K) {


Hi @ilovepi ,

These two new functions are unused in builds without asserts:

../lib/Support/Mustache.cpp:332:20: error: unused function 'tagKindToString' [-Werror,-Wunused-function] 332 | static const char *tagKindToString(Tag::Kind K) { | ^~~~~~~~~~~~~~~ ../lib/Support/Mustache.cpp:344:20: error: unused function 'jsonKindToString' [-Werror,-Wunused-function] 344 | static const char *jsonKindToString(json::Value::Kind K) { | ^~~~~~~~~~~~~~~~ 2 errors generated.

The existing logging was inconsistent, and we logged too many things. This PR introduces a more principled schema, and eliminates many, redundant log lines.

ilovepi requested review from evelez7 and petrhosek September 16, 2025 22:08

llvmbot added the llvm:support label Sep 16, 2025

ilovepi mentioned this pull request Sep 16, 2025

[llvm][mustache] Avoid extra allocations in parseSection #159199

Open

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch from a5faef5 to e0974e4 Compare September 22, 2025 17:07

ilovepi force-pushed the users/ilovepi/mustache-debug branch 2 times, most recently from ddcaf16 to e89315c Compare September 22, 2025 17:56

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch from e0974e4 to d5312d1 Compare September 22, 2025 17:56

ilovepi force-pushed the users/ilovepi/mustache-debug branch from e89315c to 68c27a3 Compare September 25, 2025 22:12

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch from d5312d1 to 56b63ac Compare September 25, 2025 22:12

ilovepi force-pushed the users/ilovepi/mustache-debug branch from 68c27a3 to c2719fb Compare September 26, 2025 01:55

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch from 56b63ac to 2819519 Compare September 26, 2025 01:55

ilovepi force-pushed the users/ilovepi/mustache-debug branch 2 times, most recently from f153c6a to f4b4bc8 Compare September 29, 2025 22:28

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch from 078165d to a211ef4 Compare September 29, 2025 22:28

ilovepi force-pushed the users/ilovepi/mustache-debug branch from f4b4bc8 to df32a14 Compare September 30, 2025 01:54

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch 2 times, most recently from 340e2ef to f2fdb9c Compare September 30, 2025 03:41

ilovepi force-pushed the users/ilovepi/mustache-debug branch from df32a14 to b22fb3e Compare September 30, 2025 03:47

ilovepi force-pushed the users/ilovepi/mustache-last-indentation branch 2 times, most recently from bd78555 to 473adbc Compare September 30, 2025 03:48

ilovepi force-pushed the users/ilovepi/mustache-debug branch from b22fb3e to 79eaa0a Compare September 30, 2025 03:48

petrhosek reviewed Sep 30, 2025

View reviewed changes

petrhosek approved these changes Sep 30, 2025

View reviewed changes

Base automatically changed from users/ilovepi/mustache-last-indentation to main October 1, 2025 00:02

[llvm][mustache] Simplify debug logging

eb3ba40

ilovepi force-pushed the users/ilovepi/mustache-debug branch from 79eaa0a to eb3ba40 Compare October 1, 2025 00:04

Make formatting consistent

d85a276

ilovepi enabled auto-merge (squash) October 1, 2025 00:18

ilovepi merged commit 9ce0dae into main Oct 1, 2025
8 of 9 checks passed

ilovepi deleted the users/ilovepi/mustache-debug branch October 1, 2025 00:47

mikaelholmen reviewed Oct 1, 2025

View reviewed changes

aemerson mentioned this pull request Oct 16, 2025

[clang-reorder-fields] Check for flexible array member (#160262) #163697

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[llvm][mustache] Simplify debug logging #159193

[llvm][mustache] Simplify debug logging #159193

Uh oh!

ilovepi commented Sep 16, 2025

Uh oh!

ilovepi commented Sep 16, 2025 •

edited

Loading

Uh oh!

llvmbot commented Sep 16, 2025

Uh oh!

github-actions bot commented Sep 16, 2025 •

edited

Loading

Uh oh!

petrhosek Sep 30, 2025 •

edited

Loading

Uh oh!

ilovepi Oct 1, 2025

Uh oh!

Uh oh!

mikaelholmen Oct 1, 2025

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

[llvm][mustache] Simplify debug logging #159193

[llvm][mustache] Simplify debug logging #159193

Uh oh!

Conversation

ilovepi commented Sep 16, 2025

Uh oh!

ilovepi commented Sep 16, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

llvmbot commented Sep 16, 2025

Uh oh!

github-actions bot commented Sep 16, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

petrhosek Sep 30, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

ilovepi Oct 1, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

mikaelholmen Oct 1, 2025

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

ilovepi commented Sep 16, 2025 •

edited

Loading

github-actions bot commented Sep 16, 2025 •

edited

Loading

petrhosek Sep 30, 2025 •

edited

Loading