[flang][preprocessor] Fix handling of #line before free-form continua…

[klausler]

…tion

See new test. A #line (or #) directive after a line ending with & and before its continuation shouldn't elicit an error about mismatched parentheses.

Fixes #100073.

[llvmbot]

@llvm/pr-subscribers-flang-parser

Author: Peter Klausler (klausler)

Changes

…tion

See new test. A #line (or #) directive after a line ending with & and before its continuation shouldn't elicit an error about mismatched parentheses.

Fixes #100073.

---

Full diff: https://github.com/llvm/llvm-project/pull/100178.diff

2 Files Affected:

• (modified) flang/lib/Parser/prescan.cpp (+5-1)
• (added) flang/test/Preprocessing/line-in-contin.F90 (+20)

diff --git a/flang/lib/Parser/prescan.cpp b/flang/lib/Parser/prescan.cpp
index aa45548408aa9..c01d512b4653d 100644
--- a/flang/lib/Parser/prescan.cpp
+++ b/flang/lib/Parser/prescan.cpp
@@ -111,9 +111,13 @@ void Prescanner::Statement() {
     skipLeadingAmpersand_ |= !inFixedForm_;
     return;
   case LineClassification::Kind::PreprocessorDirective:
+    preprocessor_.Directive(TokenizePreprocessorDirective(), *this);
+    afterPreprocessingDirective_ = true;
+    // Don't set skipLeadingAmpersand_
+    return;
   case LineClassification::Kind::DefinitionDirective:
     preprocessor_.Directive(TokenizePreprocessorDirective(), *this);
-    // Don't set afterPreprocessingDirective_
+    // Don't set afterPreprocessingDirective_ or skipLeadingAmpersand_
     return;
   case LineClassification::Kind::CompilerDirective: {
     directiveSentinel_ = line.sentinel;
diff --git a/flang/test/Preprocessing/line-in-contin.F90 b/flang/test/Preprocessing/line-in-contin.F90
new file mode 100644
index 0000000000000..138e579bffaa2
--- /dev/null
+++ b/flang/test/Preprocessing/line-in-contin.F90
@@ -0,0 +1,20 @@
+! RUN: %flang_fc1 -E %s 2>&1 | FileCheck %s
+! CHECK: call foo( 0.)
+! CHECK: call foo( 1.)
+! CHECK: call foo( 2.)
+! CHECK: call foo( 3.)
+call foo( &
+# 100 "bar.h"
+         & 0.)
+call foo( &
+# 101 "bar.h"
+         1.)
+call foo( &
+# 102 "bar.h"
+         & 2. &
+    & )
+call foo( &
+# 103 "bar.h"
+         & 3. &
+    )
+end

[mjklemm]

LGTM