Add support of musl-libc

The port is functional. Bound checking is not supported yet.

Makefile

@@ -73,6 +73,7 @@ NATIVE_DEFINES_$(CONFIG_i386) += -DTCC_TARGET_I386
 NATIVE_DEFINES_$(CONFIG_x86_64) += -DTCC_TARGET_X86_64
 NATIVE_DEFINES_$(CONFIG_WIN32) += -DTCC_TARGET_PE
 NATIVE_DEFINES_$(CONFIG_uClibc) += -DTCC_UCLIBC
+NATIVE_DEFINES_$(CONFIG_musl) += -DTCC_MUSL
 NATIVE_DEFINES_$(CONFIG_arm) += -DTCC_TARGET_ARM
 NATIVE_DEFINES_$(CONFIG_arm_eabihf) += -DTCC_ARM_EABI -DTCC_ARM_HARDFLOAT
 NATIVE_DEFINES_$(CONFIG_arm_eabi) += -DTCC_ARM_EABI

configure

@@ -352,6 +352,8 @@ if test -z "$cross_prefix" ; then
 
       if test -f "/lib/ld-uClibc.so.0" ; then
 	confvars="$confvars uClibc"
+      elif test -f "/lib/ld-musl-$cpu.so.1"; then
+        confvars="$confvars musl"
       fi
   fi
 else

include/stdarg.h

@@ -16,7 +16,11 @@ typedef struct {
     char *reg_save_area;
 } __va_list_struct;
 
+/* Avoid conflicting definition for va_list on musl libc */
+#ifndef __DEFINED_va_list
 typedef __va_list_struct va_list[1];
+#define __DEFINED_va_list
+#endif
 
 void __va_start(__va_list_struct *ap, void *fp);
 void *__va_arg(__va_list_struct *ap, int arg_type, int size, int align);

lib/Makefile

@@ -30,6 +30,10 @@ ifeq ($(TARGETOS),Darwin)
  BCHECK_O =
 endif
 
+ifeq ($(CONFIG_musl),yes)
+ BCHECK_O =
+endif
+
 I386_O = libtcc1.o alloca86.o alloca86-bt.o $(BCHECK_O)
 X86_64_O = libtcc1.o alloca86_64.o alloca86_64-bt.o $(BCHECK_O)
 ARM_O = libtcc1.o armeabi.o alloca-arm.o

lib/bcheck.c

@@ -48,7 +48,7 @@
 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) \
     || defined(__DragonFly__) || defined(__dietlibc__) \
     || defined(__UCLIBC__) || defined(__OpenBSD__) || defined(__NetBSD__) \
-    || defined(_WIN32) || defined(TCC_UCLIBC)
+    || defined(_WIN32) || defined(TCC_UCLIBC) || defined(TCC_MUSL)
 //#warning Bound checking does not support malloc (etc.) in this environment.
 #undef CONFIG_TCC_MALLOC_HOOKS
 #undef HAVE_MEMALIGN

libtcc.c

@@ -851,6 +851,10 @@ LIBTCCAPI TCCState *tcc_new(void)
     tcc_define_symbol(s, "__ILP32__", NULL);
 #endif
 
+#if defined(TCC_MUSL)
+    tcc_define_symbol(s, "__builtin_va_list", "void *");
+#endif /* TCC_MUSL */
+
 #ifdef TCC_TARGET_PE
     tcc_define_symbol(s, "__WCHAR_TYPE__", "unsigned short");
     tcc_define_symbol(s, "__WINT_TYPE__", "unsigned short");

tcc.h

@@ -136,7 +136,7 @@
 
 #if !defined(TCC_UCLIBC) && !defined(TCC_TARGET_ARM) && \
     !defined(TCC_TARGET_ARM64) && !defined(TCC_TARGET_C67) && \
-    !defined(CONFIG_USE_LIBGCC)
+    !defined(CONFIG_USE_LIBGCC) && !defined(TCC_MUSL)
 #define CONFIG_TCC_BCHECK /* enable bound checking code */
 #endif
 
@@ -239,11 +239,23 @@
 # elif defined(TCC_UCLIBC)
 #  define CONFIG_TCC_ELFINTERP "/lib/ld-uClibc.so.0" /* is there a uClibc for x86_64 ? */
 # elif defined TCC_TARGET_ARM64
-#  define CONFIG_TCC_ELFINTERP "/lib/ld-linux-aarch64.so.1"
+#  if defined(TCC_MUSL)
+#   define CONFIG_TCC_ELFINTERP "/lib/ld-musl-aarch64.so.1"
+#  else
+#   define CONFIG_TCC_ELFINTERP "/lib/ld-linux-aarch64.so.1"
+#  endif
 # elif defined(TCC_TARGET_X86_64)
-#  define CONFIG_TCC_ELFINTERP "/lib64/ld-linux-x86-64.so.2"
+#  if defined(TCC_MUSL)
+#   define CONFIG_TCC_ELFINTERP "/lib/ld-musl-x86_64.so.1"
+#  else
+#   define CONFIG_TCC_ELFINTERP "/lib64/ld-linux-x86-64.so.2"
+#  endif
 # elif !defined(TCC_ARM_EABI)
-#  define CONFIG_TCC_ELFINTERP "/lib/ld-linux.so.2"
+#  if defined(TCC_MUSL)
+#   define CONFIG_TCC_ELFINTERP "/lib/ld-musl-arm.so.1"
+#  else
+#   define CONFIG_TCC_ELFINTERP "/lib/ld-linux.so.2"
+#  endif
 # endif
 #endif
 

tccelf.c

@@ -1718,7 +1718,7 @@ static int final_sections_reloc(TCCState *s1)
     /* XXX: ignore sections with allocated relocations ? */
     for(i = 1; i < s1->nb_sections; i++) {
         s = s1->sections[i];
-#ifdef TCC_TARGET_I386
+#if defined(TCC_TARGET_I386) || defined(TCC_MUSL)
         if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr
         /* On X86 gdb 7.3 works in any case but gdb 6.6 will crash if SHF_ALLOC
         checking is removed */