[build] Enable building with the Intel C compiler (icc)

src/util/iccfix.c

@@ -0,0 +1,156 @@
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <elf.h>
+#include <gpxe/tables.h>
+
+#define DEBUG 0
+
+#define eprintf(...) fprintf ( stderr, __VA_ARGS__ )
+
+#define dprintf(...) do {						\
+	if ( DEBUG )							\
+		fprintf ( stderr, __VA_ARGS__ );			\
+	} while ( 0 )
+
+#ifdef SELF_INCLUDED
+
+/**
+ * Fix up ICC alignments
+ *
+ * @v elf		ELF header
+ * @ret rc		Return status code
+ *
+ * See comments in tables.h for an explanation of why this monstrosity
+ * is necessary.
+ */
+static int ICCFIX ( void *elf ) {
+	ELF_EHDR *ehdr = elf;
+	ELF_SHDR *shdr = ( elf + ehdr->e_shoff );
+	size_t shentsize = ehdr->e_shentsize;
+	unsigned int shnum = ehdr->e_shnum;
+	ELF_SHDR *strtab = ( ( ( void * ) shdr ) +
+			     ( ehdr->e_shstrndx * shentsize ) );
+	char *strings = ( elf + strtab->sh_offset );
+
+	for ( ; shnum-- ; shdr = ( ( ( void * ) shdr ) + shentsize ) ) {
+		char *name = ( strings + shdr->sh_name );
+		unsigned long align = shdr->sh_addralign;
+		unsigned long new_align;
+
+		if ( ( strncmp ( name, ".tbl.", 5 ) == 0 ) &&
+		     ( align >= ICC_ALIGN_HACK_FACTOR ) ) {
+			new_align = ( align / ICC_ALIGN_HACK_FACTOR );
+			shdr->sh_addralign = new_align;
+			dprintf ( "Section \"%s\": alignment %d->%d\n",
+				  name, align, new_align );
+		}
+	}
+	return 0;
+}
+
+#else /* SELF_INCLUDED */
+
+#define SELF_INCLUDED
+
+/* Include iccfix32() function */
+#define ELF_EHDR Elf32_Ehdr
+#define ELF_SHDR Elf32_Shdr
+#define ICCFIX iccfix32
+#include "iccfix.c"
+#undef ELF_EHDR
+#undef ELF_SHDR
+#undef ICCFIX
+
+/* Include iccfix64() function */
+#define ELF_EHDR Elf64_Ehdr
+#define ELF_SHDR Elf64_Shdr
+#define ICCFIX iccfix64
+#include "iccfix.c"
+#undef ELF_EHDR
+#undef ELF_SHDR
+#undef ICCFIX
+
+static int iccfix ( const char *filename ) {
+	int fd;
+	struct stat stat;
+	void *elf;
+	unsigned char *eident;
+	int rc;
+
+	/* Open and mmap file */
+	fd = open ( filename, O_RDWR );
+	if ( fd < 0 ) {
+		eprintf ( "Could not open %s: %s\n",
+			  filename, strerror ( errno ) );
+		rc = -1;
+		goto err_open;
+	}
+	if ( fstat ( fd, &stat ) < 0 ) {
+		eprintf ( "Could not determine size of %s: %s\n",
+			  filename, strerror ( errno ) );
+		rc = -1;
+		goto err_fstat;
+	}
+	elf = mmap ( NULL, stat.st_size, ( PROT_READ | PROT_WRITE ),
+		     MAP_SHARED, fd, 0 );
+	if ( elf == MAP_FAILED ) {
+		eprintf ( "Could not map %s: %s\n",
+			  filename, strerror ( errno ) );
+		rc = -1;
+		goto err_mmap;
+	}
+
+	/* Perform fixups */
+	eident = elf;
+	switch ( eident[EI_CLASS] ) {
+	case ELFCLASS32:
+		rc = iccfix32 ( elf );
+		break;
+	case ELFCLASS64:
+		rc = iccfix64 ( elf );
+		break;
+	default:
+		eprintf ( "Unknown ELF class %d in %s\n",
+			  eident[EI_CLASS], filename );
+		rc = -1;
+		break;
+	}
+
+	munmap ( elf, stat.st_size );
+ err_mmap:
+ err_fstat:
+	close ( fd );
+ err_open:
+	return rc;
+}
+
+int main ( int argc, char **argv ) {
+	int i;
+	int rc;
+
+	/* Parse command line */
+	if ( argc < 2 ) {
+		eprintf ( "Syntax: %s <object_file>...\n", argv[0] );
+		exit ( 1 );
+	}
+
+	/* Process each object in turn */
+	for ( i = 1 ; i < argc ; i++ ) {
+		if ( ( rc = iccfix ( argv[i] ) ) != 0 ) {
+			eprintf ( "Could not fix up %s\n", argv[i] );
+			exit ( 1 );
+		}
+	}
+
+	return 0;
+}
+
+#endif /* SELF_INCLUDED */