Add elf_read_next_u*
For stream-like reading of ELF data.
diff --git a/ltrace-elf.c b/ltrace-elf.c
index d9dac5e..b2e6e07 100644
--- a/ltrace-elf.c
+++ b/ltrace-elf.c
@@ -244,6 +244,24 @@
#undef DEF_READER
+#define DEF_READER(NAME, SIZE) \
+ int \
+ NAME(Elf_Data *data, GElf_Xword *offset, uint##SIZE##_t *retp) \
+ { \
+ int rc = elf_read_u##SIZE(data, *offset, retp); \
+ if (rc < 0) \
+ return rc; \
+ *offset += SIZE / 8; \
+ return 0; \
+ }
+
+DEF_READER(elf_read_next_u8, 8)
+DEF_READER(elf_read_next_u16, 16)
+DEF_READER(elf_read_next_u32, 32)
+DEF_READER(elf_read_next_u64, 64)
+
+#undef DEF_READER
+
int
open_elf(struct ltelf *lte, const char *filename)
{
diff --git a/ltrace-elf.h b/ltrace-elf.h
index a50ad8a..a520e63 100644
--- a/ltrace-elf.h
+++ b/ltrace-elf.h
@@ -116,6 +116,13 @@
int elf_read_u32(Elf_Data *data, GElf_Xword offset, uint32_t *retp);
int elf_read_u64(Elf_Data *data, GElf_Xword offset, uint64_t *retp);
+/* These are same as above, but update *OFFSET with the width
+ * of read datum. */
+int elf_read_next_u8(Elf_Data *data, GElf_Xword *offset, uint8_t *retp);
+int elf_read_next_u16(Elf_Data *data, GElf_Xword *offset, uint16_t *retp);
+int elf_read_next_u32(Elf_Data *data, GElf_Xword *offset, uint32_t *retp);
+int elf_read_next_u64(Elf_Data *data, GElf_Xword *offset, uint64_t *retp);
+
#if __WORDSIZE == 32
#define PRI_ELF_ADDR PRIx32
#define GELF_ADDR_CAST(x) (void *)(uint32_t)(x)