[flang-commits] [flang] [FLANG] Solved an issue with continuation lines (PR #146027)

[via flang-commits]

https://github.com/EbinJose2002 created https://github.com/llvm/llvm-project/pull/146027

Solved the issue with c style comment appearing between continuation lines
Wrote a test file for it.
Fixes #129455

>From c5d74fe137f6e75c776d79ccaedd58d223bf6d14 Mon Sep 17 00:00:00 2001
From: EbinJose2002 <ebin.jose at multicorewareinc.com>
Date: Wed, 25 Jun 2025 14:18:29 +0530
Subject: [PATCH 1/2] Solving issue with c style comments preceding
 continuation lines Adeed test file for the issue

---
 flang/lib/Parser/prescan.cpp                     |  4 ++++
 flang/test/Parser/continuation-after-comment.f90 | 15 +++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 flang/test/Parser/continuation-after-comment.f90

diff --git a/flang/lib/Parser/prescan.cpp b/flang/lib/Parser/prescan.cpp
index 9aef0c9981e3c..5c92974e3ebf2 100644
--- a/flang/lib/Parser/prescan.cpp
+++ b/flang/lib/Parser/prescan.cpp
@@ -1455,6 +1455,10 @@ const char *Prescanner::FreeFormContinuationLine(bool ampersand) {
       return nullptr;
     }
   }
+  if (p[0] == '/' && p[1] == '*') {
+    p = SkipCComment(p);
+    p = SkipWhiteSpaceIncludingEmptyMacros(p);
+  }
   if (p[0] == '!' && p[1] == '$' && !preprocessingOnly_ &&
       features_.IsEnabled(LanguageFeature::OpenMP)) {
     // !$ conditional line can be a continuation
diff --git a/flang/test/Parser/continuation-after-comment.f90 b/flang/test/Parser/continuation-after-comment.f90
new file mode 100644
index 0000000000000..62746f9ad2b4b
--- /dev/null
+++ b/flang/test/Parser/continuation-after-comment.f90
@@ -0,0 +1,15 @@
+! RUN: %flang_fc1 -E %s 2>&1 | FileCheck %s
+
+!Checking comments appearing in between continuation lines.
+integer &
+i(1)
+/* \\\*/
+!CHECK: integer i(1)
+i(1)&
+/* \\\*/
+=1
+!CHECK: i(1) =1
+/* \*/
+if (i(1)/=1)write(6,*)'error',i(1)
+print *,'pass'
+end
\ No newline at end of file

>From c3444f3db4d4317b84adf68cee594a4a18c294dc Mon Sep 17 00:00:00 2001
From: Ebin-McW <ebin.jose at multicorewareinc.com>
Date: Thu, 26 Jun 2025 12:50:46 +0530
Subject: [PATCH 2/2] Update continuation-after-comment.f90

---
 flang/test/Parser/continuation-after-comment.f90 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flang/test/Parser/continuation-after-comment.f90 b/flang/test/Parser/continuation-after-comment.f90
index 62746f9ad2b4b..845aa8bc36e5c 100644
--- a/flang/test/Parser/continuation-after-comment.f90
+++ b/flang/test/Parser/continuation-after-comment.f90
@@ -12,4 +12,4 @@
 /* \*/
 if (i(1)/=1)write(6,*)'error',i(1)
 print *,'pass'
-end
\ No newline at end of file
+end