Add static library support

hold can now open archives (smartly!) and link against them. Also fix a few bugs found in the process. Signed-off-by: Pedro Falcato <[email protected]>
heatd · Nov 22, 2023 · 7882cf6 · 7882cf6
1 parent 4f07b32
commit 7882cf6
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Showing 9 changed files with 634 additions and 101 deletions.
diff --git a/include/elf/ar.h b/include/elf/ar.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2023 Pedro Falcato */
+#ifndef ELF_AR_H
+#define ELF_AR_H
+
+#include <string.h>
+
+#define AR_MAGIC "!<arch>\n"
+#define	ARFMAG	"`\n"
+
+struct ar_hdr {
+        char ar_name[16];
+        char ar_date[12];
+        char ar_uid[6];
+        char ar_gid[6];
+        char ar_mode[8];
+        char ar_size[10];
+        char ar_fmag[2];
+};
+
+static inline int is_ar_archive(const void *buf)
+{
+        return !memcmp(buf, AR_MAGIC, strlen(AR_MAGIC));
+}
+
+struct input_file;
+struct symbol;
+
+int parse_ar(struct input_file *file, const void *mapping, unsigned long filesz);
+int resolve_lazy(struct symbol *sym);
+
+#endif
diff --git a/include/elf/elf.h b/include/elf/elf.h
@@ -37,7 +37,13 @@ struct symbol {
          * has not been an overridden symbol.
          */
         u8 nofree_name : 1;
-        struct input_section *section;
+
+        /* For lazy symbols, this holds the position in the ar archive */
+        u32 ar_pos;
+        union {
+                struct input_section *section;
+                struct input_file *file;
+        };
 
         struct symbol *next;
 };
@@ -81,16 +87,40 @@ struct input_section {
         muptr output_off;
 };
 
+struct ar_archive_data;
+
+struct input_file_ops {
+        int (*open)(struct input_file *file);
+        void (*read)(struct input_file *file, void *buf, uptr size, uptr offset);
+        void (*close)(struct input_file *file);
+};
+
 struct input_file {
         const char *name;
         u16 emachine;
+        u32 free_name : 1;
 
         struct input_section *sections;
         u32 nsections;
         struct symbol *syms;
         u32 nsyms;
         struct relocation *relocs;
         u32 nrelocs;
+
+        struct ar_archive_data *ardata;
+
+        struct {
+                u8 *long_file_names;
+        } archive;
+
+        union {
+                int fd;
+                struct {
+                        uptr archive_off;
+                };
+        } openf;
+
+        const struct input_file_ops *ops;
 };
 
 typedef Elf64_Ehdr elf_ehdr;
@@ -102,13 +132,13 @@ typedef Elf64_Phdr elf_phdr;
 int process_rela(struct input_file *file, elf_shdr *section, u8 *mapping);
 struct symbol *lookup_symtable(const char *name);
 
-struct output_section *elf_merge_sections(struct input_file **files, u32 nfiles,
+struct output_section **elf_merge_sections(struct input_file **files, u32 nfiles,
                                           u32 *p_noutput);
 
 struct program_header;
 
 struct elf_writer {
-        struct output_section *out_section;
+        struct output_section **out_section;
         u32 nr_output_secs;
         struct hold_options *options;
         struct input_file **files;
@@ -126,4 +156,12 @@ void relocate_symbols(void);
 
 void elf_do_relocs(struct input_file *file, struct relocation *relocs, u32 nrelocs, u8 *mapping);
 
+int add_to_symtable(struct symbol *sym);
+
+/* If set, we should free this filename (as it was malloc'd) */
+#define ELF_PROCESS_FILENAME_FREE (1 << 0)
+
+int elf_process_objfile(const char *filename, void *map, uptr fd_size,
+                        const struct input_file_ops *ops, int flags);
+
 #endif