[clang] [clang-format] Improve BlockIndent at ColumnLimit (PR #93140)

[Owen Pan via cfe-commits]

owenca wrote:

You can annotate the lambda l_paren:
```
$ git diff FormatToken.h
diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h
index cc45d5a8c5c1..abcedb66b57c 100644
--- a/clang/lib/Format/FormatToken.h
+++ b/clang/lib/Format/FormatToken.h
@@ -102,6 +102,7 @@ namespace format {
   TYPE(JsTypeColon)                                                            \
   TYPE(JsTypeOperator)                                                         \
   TYPE(JsTypeOptionalQuestion)                                                 \
+  TYPE(LambdaDefinitionLParen)                                                 \
   TYPE(LambdaLBrace)                                                           \
   TYPE(LambdaLSquare)                                                          \
   TYPE(LeadingJavaAnnotation)                                                  \
$ git diff TokenAnnotator.cpp
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index fe8a126e2547..fa1489402559 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -62,6 +62,7 @@ static bool canBeObjCSelectorComponent(const FormatToken &Tok) {
 
 /// With `Left` being '(', check if we're at either `[...](` or
 /// `[...]<...>(`, where the [ opens a lambda capture list.
+// FIXME: this doesn't cover attributes/constraints before the l_paren.
 static bool isLambdaParameterList(const FormatToken *Left) {
   // Skip <...> if present.
   if (Left->Previous && Left->Previous->is(tok::greater) &&
@@ -365,6 +366,7 @@ private:
       Contexts.back().IsExpression = false;
     } else if (isLambdaParameterList(&OpeningParen)) {
       // This is a parameter list of a lambda expression.
+      OpeningParen.setType(TT_LambdaDefinitionLParen);
       Contexts.back().IsExpression = false;
     } else if (OpeningParen.is(TT_RequiresExpressionLParen)) {
       Contexts.back().IsExpression = false;
$ 
```

https://github.com/llvm/llvm-project/pull/93140