[PATCH 2/2] options: add support for -mcmodel

[Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>]

Do the parsing of all models used in the kernel and
output the predefines for arm64 & riscv.

Reported-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
 lib.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib.h | 13 +++++++++
 2 files changed, 99 insertions(+)

diff --git a/lib.c b/lib.c
index e9e637d29..84b5be6a8 100644
--- a/lib.c
+++ b/lib.c
@@ -328,6 +328,7 @@ static int arch_msize_long = 0;
 int arch_m64 = ARCH_M64_DEFAULT;
 int arch_big_endian = ARCH_BIG_ENDIAN;
 int arch_mach = MACH_NATIVE;
+int arch_cmodel = CMODEL_UNKNOWN;
 
 
 #define CMDLINE_INCLUDE 20
@@ -470,6 +471,26 @@ static char **handle_switch_m(char *arg, char **next)
 		arch_big_endian = 1;
 	} else if (!strcmp(arg, "mlittle-endian")) {
 		arch_big_endian = 0;
+	} else if (!strncmp(arg, "mcmodel", 7)) {
+		arg += 7;
+		if (*arg++ != '=')
+			die("missing argument for -mcmodel");
+		else if (!strcmp(arg, "kernel"))
+			arch_cmodel = CMODEL_KERNEL;
+		else if (!strcmp(arg, "large"))
+			arch_cmodel = CMODEL_LARGE;
+		else if (!strcmp(arg, "medany"))
+			arch_cmodel = CMODEL_MEDANY;
+		else if (!strcmp(arg, "medium"))
+			arch_cmodel = CMODEL_MEDIUM;
+		else if (!strcmp(arg, "medlow"))
+			arch_cmodel = CMODEL_MEDLOW;
+		else if (!strcmp(arg, "small"))
+			arch_cmodel = CMODEL_SMALL;
+		else if (!strcmp(arg, "tiny"))
+			arch_cmodel = CMODEL_TINY;
+		else
+			die("invalid argument for -mcmodel=%s", arg);
 	}
 	return next;
 }
@@ -488,6 +509,20 @@ static void handle_arch_finalize(void)
 
 	if (fpie > fpic)
 		fpic = fpie;
+
+	switch (arch_mach) {
+	case MACH_ARM64:
+		if (arch_cmodel == CMODEL_UNKNOWN)
+			arch_cmodel = CMODEL_SMALL;
+		break;
+	case MACH_RISCV32:
+	case MACH_RISCV64:
+		if (arch_cmodel == CMODEL_UNKNOWN)
+			arch_cmodel = CMODEL_MEDLOW;
+		if (fpic)
+			arch_cmodel = CMODEL_PIC;
+		break;
+	}
 }
 
 static const char *match_option(const char *arg, const char *prefix)
@@ -1213,6 +1248,55 @@ static void predefined_ctype(const char *name, struct symbol *type, int flags)
 		predefined_width(name, bits);
 }
 
+static void predefined_cmodel(void)
+{
+	const char *pre, *suf;
+	const char *def = NULL;
+	switch (arch_mach) {
+	case MACH_ARM64:
+		pre = "__AARCH64_CMODEL_";
+		suf = "__";
+		switch (arch_cmodel) {
+		case CMODEL_LARGE:
+			def = "LARGE";
+			break;
+		case CMODEL_SMALL:
+			def = "SMALL";
+			break;
+		case CMODEL_TINY:
+			def = "TINY";
+			break;
+		default:
+			break;
+		}
+		break;
+	case MACH_RISCV32:
+	case MACH_RISCV64:
+		pre = "__riscv_cmodel_";
+		suf = "";
+		switch (arch_cmodel) {
+		case CMODEL_MEDLOW:
+			def = "medlow";
+			break;
+		case CMODEL_MEDANY:
+			def = "medany";
+			break;
+		case CMODEL_PIC:
+			def = "pic";
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (!def)
+		return;
+	add_pre_buffer("#weak_define %s%s%s 1\n", pre, def, suf);
+}
+
 static void predefined_macros(void)
 {
 	predefine("__CHECKER__", 0, "1");
@@ -1406,6 +1490,8 @@ static void predefined_macros(void)
 		predefine("__pie__", 0, "%d", fpie);
 		predefine("__PIE__", 0, "%d", fpie);
 	}
+
+	predefined_cmodel();
 }
 
 static void create_builtin_stream(void)
diff --git a/lib.h b/lib.h
index b3616fd45..f6dea8ca2 100644
--- a/lib.h
+++ b/lib.h
@@ -207,6 +207,19 @@ extern int arch_m64;
 extern int arch_big_endian;
 extern int arch_mach;
 
+enum {
+	CMODEL_UNKNOWN,
+	CMODEL_KERNEL,
+	CMODEL_LARGE,
+	CMODEL_MEDANY,
+	CMODEL_MEDIUM,
+	CMODEL_MEDLOW,
+	CMODEL_PIC,
+	CMODEL_SMALL,
+	CMODEL_TINY,
+};
+extern int arch_cmodel;
+
 extern void dump_macro_definitions(void);
 extern struct symbol_list *sparse_initialize(int argc, char **argv, struct string_list **files);
 extern struct symbol_list *__sparse(char *filename);
-- 
2.23.0