From fe34aba06029a86df15742b983cd398580ca3b94 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 18 Jul 2023 10:02:14 -0600 Subject: [PATCH] Fix bug in fixed-point handling Alexandre Oliva found a bug in gdb's handling of fixed-point -- a certain Ada fixed-point type would be misintepreted. The bug was that the DW_AT_small looked like: <1><13cd>: Abbrev Number: 16 (DW_TAG_constant) <13ce> DW_AT_GNU_numerator: 1 <13cf> DW_AT_GNU_denominator: 0x8000000000000000 ... but gdb interpreted the denominator as a negative value. --- gdb/dwarf2/read.c | 2 ++ gdb/testsuite/gdb.ada/fixed_points.exp | 3 +++ gdb/testsuite/gdb.ada/fixed_points/fixed_points.adb | 8 ++++++++ 3 files changed, 13 insertions(+) diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index b1f1c1d7257..61730f6481c 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -14867,6 +14867,8 @@ get_mpz (struct dwarf2_cu *cu, gdb_mpz *value, struct attribute *attr) ? BFD_ENDIAN_BIG : BFD_ENDIAN_LITTLE, true); } + else if (attr->form_is_unsigned ()) + *value = gdb_mpz (attr->as_unsigned ()); else *value = gdb_mpz (attr->constant_value (1)); } diff --git a/gdb/testsuite/gdb.ada/fixed_points.exp b/gdb/testsuite/gdb.ada/fixed_points.exp index ed61cab4bec..2edc63f4071 100644 --- a/gdb/testsuite/gdb.ada/fixed_points.exp +++ b/gdb/testsuite/gdb.ada/fixed_points.exp @@ -91,4 +91,7 @@ foreach_with_prefix scenario {all minimal} { if {$scenario == "minimal" && [test_compiler_info {gcc-11-*}]} { gdb_test "print fp5_var" " = 3e-19" } + + gdb_test "p Float(Another_Fixed) = Float(Another_Delta * 5)" "true" \ + "value of another_fixed" } diff --git a/gdb/testsuite/gdb.ada/fixed_points/fixed_points.adb b/gdb/testsuite/gdb.ada/fixed_points/fixed_points.adb index 67d38f2770b..edcbac80ef9 100644 --- a/gdb/testsuite/gdb.ada/fixed_points/fixed_points.adb +++ b/gdb/testsuite/gdb.ada/fixed_points/fixed_points.adb @@ -57,6 +57,13 @@ procedure Fixed_Points is FP5_Var : FP5_Type := 3 * Delta5; + + Another_Delta : constant := 1.0/(2**63); + type Another_Type is delta Another_Delta range -1.0 .. (1.0 - Another_Delta); + for Another_Type'small use Another_Delta; + for Another_Type'size use 64; + Another_Fixed : Another_Type := Another_Delta * 5; + begin Base_Object := 1.0/16.0; -- Set breakpoint here Subtype_Object := 1.0/16.0; @@ -67,4 +74,5 @@ begin Do_Nothing (FP3_Var'Address); Do_Nothing (FP4_Var'Address); Do_Nothing (FP5_Var'Address); + Do_Nothing (Another_Fixed'Address); end Fixed_Points; -- 2.30.2