Add configuration to set the debug symbol level

Default to -g1 to strike a balance between symbol utility and
compilation speed.

README.md

@@ -336,6 +336,7 @@ The following options may be specified to configure the build:
 | `mode`        | `debug`, `release`, `profile` | `debug`                       | Compilation mode<sup>2</sup>. |
 | `arch`        | `x86`, `x64`                  | Defaults to host architecture | Compilation architecture, 32-bit or 64-bit. |
 | `strict`      | `0`, `1`, `2`                 | `2`                           | Compiler warning level<sup>3</sup>. |
+| `symbols`     | Any valid `-g` option         | `1`                           | Debug symbol level, passed directly to `-g`. |
 | `cstandard`   | Any valid `-std` option       | `c2x`                         | The language standard to use for C files, passed directly to `-std`. |
 | `cxxstandard` | Any valid `-std` option       | `c++2a`                       | The language standard to use for C++ files, passed directly to `-std`. |
 | `linker`      | Any valid `-fuse-ld` option   | `lld` on Linux, `ld` on macOS | The linker to use for creating executables, passed directly to `-fuse-ld`. |

src/config.mk

@@ -16,6 +16,9 @@ arch ?= $(arch)
 # Compiler warning level (0, 1, 2).
 strict ?= 2
 
+# Debug symbol level (0, 1, 2, 3).
+symbols ?= 1
+
 # C language standard.
 cstandard ?= c2x
 

src/flags.mk

@@ -150,14 +150,14 @@ JFLAGS += \
 
 # Add debug symbols, optimize release builds, or add profiling symbols.
 ifeq ($(mode), debug)
-    CF_ALL += -O0 -g
+    CF_ALL += -O0 -g$(symbols)
     JFLAGS += -g:lines,vars,source
 else ifeq ($(mode), release)
     CF_ALL += -O2 -DNDEBUG
     JFLAGS += -g:none
 else ifeq ($(mode), profile)
     ifeq ($(toolchain), gcc)
-        CF_ALL += -O2 -DNDEBUG -g -pg -DFLY_PROFILE
+        CF_ALL += -O2 -DNDEBUG -g$(symbols) -pg -DFLY_PROFILE
         LDFLAGS += -pg
     else
         $(error Profiling not supported with toolchain $(toolchain), check flags.mk)