Prefix public bitfield macros with LBT_ to avoid namespace pollution (#177)

* Prefix public bitfield macros with `LBT_` to avoid namespace pollution

`src/libblastrampoline.h` is the public header, but it defined the unprefixed
macros `BF_CHUNK`, `BF_MASK`, and `BITFIELD_{GET,SET,CLEAR}` into every
consumer's namespace. `BF_MASK` in particular is a likely collision.

Rename them to `LBT_`-prefixed names (`LBT_BF_CHUNK`, `LBT_BF_MASK`,
`LBT_BITFIELD_{GET,SET,CLEAR}`) and update the in-tree usages. The three
documented public macros (`BITFIELD_{GET,SET,CLEAR}`, referenced from the
`active_forwards` docstring) are kept as backwards-compatible aliases so
existing consumers don't break; `BF_CHUNK`/`BF_MASK` were internal helpers and
are renamed without aliases.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Drop the unprefixed bitfield macro aliases

Per review discussion, remove the backwards-compatible `BITFIELD_{GET,SET,CLEAR}`
aliases and keep only the `LBT_`-prefixed macros. These are compile-time-only
helper macros (not exported symbols), so removing them does not affect the ABI /
soversion — no major version bump required.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ViralBShah

src/config.c

@@ -60,7 +60,7 @@ void clear_forwarding_mark(int32_t symbol_idx, int32_t interface) {
             continue;
         }
 
-        BITFIELD_CLEAR(lbt_config.loaded_libs[idx]->active_forwards, symbol_idx);
+        LBT_BITFIELD_CLEAR(lbt_config.loaded_libs[idx]->active_forwards, symbol_idx);
     }
 }
 

src/libblastrampoline.c

@@ -407,7 +407,7 @@ LBT_DLLEXPORT int32_t lbt_forward(const char * libname, int32_t clear, int32_t v
 
         if (addr != NULL && addr != self_symbol_addr) {
             lbt_set_forward_by_index(symbol_idx,  addr, interface, complex_retstyle, f2c, verbose);
-            BITFIELD_SET(forwards, symbol_idx);
+            LBT_BITFIELD_SET(forwards, symbol_idx);
             nforwards++;
         }
     }

src/libblastrampoline.h

@@ -38,11 +38,11 @@ extern "C" {
 # define LBT_HIDDEN    __attribute__ ((visibility("hidden")))
 #endif
 
-#define BF_CHUNK(array, idx)           (array[((uint32_t)(idx/8))])
-#define BF_MASK(idx)                   ((uint8_t)(0x1 << (idx % 8)))
-#define BITFIELD_GET(array, idx)      ((BF_CHUNK(array, idx) &  BF_MASK(idx)) >> (idx % 8))
-#define BITFIELD_CLEAR(array, idx)      BF_CHUNK(array, idx) &= ~(BF_MASK(idx))
-#define BITFIELD_SET(array, idx)        BF_CHUNK(array, idx) |=   BF_MASK(idx)
+#define LBT_BF_CHUNK(array, idx)       (array[((uint32_t)(idx/8))])
+#define LBT_BF_MASK(idx)               ((uint8_t)(0x1 << (idx % 8)))
+#define LBT_BITFIELD_GET(array, idx)  ((LBT_BF_CHUNK(array, idx) &  LBT_BF_MASK(idx)) >> (idx % 8))
+#define LBT_BITFIELD_CLEAR(array, idx)  LBT_BF_CHUNK(array, idx) &= ~(LBT_BF_MASK(idx))
+#define LBT_BITFIELD_SET(array, idx)    LBT_BF_CHUNK(array, idx) |=   LBT_BF_MASK(idx)
 
 
 // The metadata stored on each loaded library
@@ -55,7 +55,7 @@ typedef struct {
     // Common values are `""` or `"64_"`.
     const char * suffix;
     // bitfield (in uint8_t form) representing the active forwards for this library.
-    // Use the `BITFIELD_{SET,GET}` macros to look at particular indices within this field.
+    // Use the `LBT_BITFIELD_{SET,GET}` macros to look at particular indices within this field.
     // Note that if you use the footgun API (e.g. "lbt_set_forward()") these values will be
     // zeroed out and you must track them manually if you need to.
     uint8_t * active_forwards;