[binutils-gdb] Fix bug in ada_print_floating

[binutils-gdb] Fix bug in ada_print_floating

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=aacf24b4db3422632d6b62d473faf71f4e737072

commit aacf24b4db3422632d6b62d473faf71f4e737072
Author: Tom Tromey <tromey@adacore.com>
Date:   Wed Feb 16 12:33:45 2022 -0700

    Fix bug in ada_print_floating
    
    ada_print_floating rewrites a floating-point string representation to
    conform to Ada syntax.  However, if you managed to get a floating
    point error, you might see:
    
        (gdb) print whatever
        $2 = <invalid float valu.0e>
    
    What's happening here is that ada_print_floating doesn't recognize
    this error case, and proceeds to modify the error text.
    
    This patch fixes this problem.

Diff:
---
 gdb/ada-valprint.c                   | 7 +++++++
 gdb/testsuite/gdb.ada/float-bits.exp | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/gdb/ada-valprint.c b/gdb/ada-valprint.c
index bf95719f040..e113088491c 100644
--- a/gdb/ada-valprint.c
+++ b/gdb/ada-valprint.c
@@ -314,6 +314,13 @@ ada_print_floating (const gdb_byte *valaddr, struct type *type,
   std::string s = tmp_stream.release ();
   size_t skip_count = 0;
 
+  /* Don't try to modify a result representing an error.  */
+  if (s[0] == '<')
+    {
+      fputs_filtered (s.c_str (), stream);
+      return;
+    }
+
   /* Modify for Ada rules.  */
 
   size_t pos = s.find ("inf");
diff --git a/gdb/testsuite/gdb.ada/float-bits.exp b/gdb/testsuite/gdb.ada/float-bits.exp
index 61db5f325ad..c98afb53c06 100644
--- a/gdb/testsuite/gdb.ada/float-bits.exp
+++ b/gdb/testsuite/gdb.ada/float-bits.exp
@@ -48,3 +48,6 @@ gdb_test "print val_long_double := 16llf#7FFFF7FF4054A56FA5B99019A5C8#" \
     " = 5.0e\\+25"
 gdb_test "print val_long_double" " = 5.0e\\+25" \
     "print val_long_double after assignment"
+
+gdb_test "print 16llf#a56fa5b99019a5c800007ffff7ff4054#" \
+    " = <invalid float value>"