diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 0da4075..e107189 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -3115,7 +3115,7 @@ either your program or GCC: @item -g @opindex g Produce debugging information in the operating system's native format -(stabs, COFF, XCOFF, or DWARF)@. GDB can work with this debugging +(stabs, COFF, XCOFF, or DWARF 2)@. GDB can work with this debugging information. On most systems that use stabs format, @option{-g} enables use of extra @@ -3126,7 +3126,7 @@ refuse to read the program. If you want to control for certain whether to generate the extra information, use @option{-gstabs+}, @option{-gstabs}, @option{-gxcoff+}, @option{-gxcoff}, or @option{-gvms} (see below). -Unlike most other C compilers, GCC allows you to use @option{-g} with +GCC allows you to use @option{-g} with @option{-O}. The shortcuts taken by optimized code may occasionally produce surprising results: some variables you declared may not exist at all; flow of control may briefly move where you did not expect it; @@ -3189,7 +3189,10 @@ assembler (GAS) to fail with an error. @item -gdwarf-2 @opindex gdwarf-2 Produce debugging information in DWARF version 2 format (if that is -supported). This is the format used by DBX on IRIX 6. +supported). This is the format used by DBX on IRIX 6. With this +option, GCC uses features of DWARF version 3 when they are useful; +version 3 is upward compatible with version 2, but may still cause +problems for older debuggers. @item -gvms @opindex gvms @@ -3214,10 +3217,13 @@ Level 3 includes extra information, such as all the macro definitions present in the program. Some debuggers support macro expansion when you use @option{-g3}. -Note that in order to avoid confusion between DWARF1 debug level 2, -and DWARF2 @option{-gdwarf-2} does not accept a concatenated debug -level. Instead use an additional @option{-g@var{level}} option to -change the debug level for DWARF2. +@option{-gdwarf-2} does not accept a concatenated debug level, because +GCC used to support an option @option{-gdwarf} that meant to generate +debug information in version 1 of the DWARF format (which is very +different from version 2), and it would have been too confusing. That +debug format is long obsolete, but the option cannot be changed now. +Instead use an additional @option{-g@var{level}} option to change the +debug level for DWARF2. @item -feliminate-dwarf2-dups @opindex feliminate-dwarf2-dups |