[clang] [clang-format] Don't split "DPI"/"DPI-C" in imports (PR #66951)

[Arthur Eubanks via cfe-commits]

https://github.com/aeubanks created https://github.com/llvm/llvm-project/pull/66951

The spec doesn't allow splitting these strings and we're seeing compile issues with splitting it.

String splitting was enabled for Verilog in https://reviews.llvm.org/D154093.


>From b52605303495001902354baab9b9b5ed3b5e186a Mon Sep 17 00:00:00 2001
From: Arthur Eubanks <aeubanks at google.com>
Date: Wed, 20 Sep 2023 13:42:20 -0700
Subject: [PATCH] [clang-format] Don't split "DPI"/"DPI-C" in imports

The spec doesn't allow splitting these strings and we're seeing compile issues with splitting it.

String splitting was enabled for Verilog in https://reviews.llvm.org/D154093.
---
 clang/lib/Format/ContinuationIndenter.cpp    | 8 ++++++++
 clang/unittests/Format/FormatTestVerilog.cpp | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index deb3e554fdc124b..0bdf339d8df5827 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -2270,7 +2270,15 @@ ContinuationIndenter::createBreakableToken(const FormatToken &Current,
     if (State.Stack.back().IsInsideObjCArrayLiteral)
       return nullptr;
 
+    // The "DPI" (or "DPI-C") in SystemVerilog direct programming interface
+    // imports cannot be split, e.g.
+    // `import "DPI" function foo();`
+    // FIXME: We should see if this is an import statement instead of hardcoding
+    // "DPI"/"DPI-C".
     StringRef Text = Current.TokenText;
+    if (Style.isVerilog() && (Text == "\"DPI\"" || Text == "\"DPI-C\""))
+      return nullptr;
+
     // We need this to address the case where there is an unbreakable tail only
     // if certain other formatting decisions have been taken. The
     // UnbreakableTailLength of Current is an overapproximation in that case and
diff --git a/clang/unittests/Format/FormatTestVerilog.cpp b/clang/unittests/Format/FormatTestVerilog.cpp
index 945e06143ccc3f1..56a8d19a31e919c 100644
--- a/clang/unittests/Format/FormatTestVerilog.cpp
+++ b/clang/unittests/Format/FormatTestVerilog.cpp
@@ -1253,6 +1253,12 @@ TEST_F(FormatTestVerilog, StringLiteral) {
    "xxxx"});)",
                R"(x({"xxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxx ", "xxxx"});)",
                getStyleWithColumns(getDefaultStyle(), 23));
+  // "DPI"/"DPI-C" in imports cannot be split.
+  verifyFormat(R"(import
+    "DPI-C" function t foo
+    ();)",
+               R"(import "DPI-C" function t foo();)",
+               getStyleWithColumns(getDefaultStyle(), 23));
   // These kinds of strings don't exist in Verilog.
   verifyNoCrash(R"(x(@"xxxxxxxxxxxxxxxx xxxx");)",
                 getStyleWithColumns(getDefaultStyle(), 23));