Initial commit

1 files changed, 317 insertions, 0 deletions

diff --git a/files.c b/files.c
new file mode 100644
index 00000000..51a8740c
--- /dev/null
+++ b/files.c
@@ -0,0 +1,317 @@
+//
+// files.c - Implementation of some file loading functionality.
+//
+
+#include <err.h>
+#include <fcntl.h>
+#include <gc.h>
+#include <libgen.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/param.h>
+
+#include "files.h"
+#include "util.h"
+
+static const int tabstop = 4;
+
+public char *resolve_path(const char *path, const char *relative_to)
+{
+    if (!relative_to || streq(relative_to, "/dev/stdin")) relative_to = ".";
+    if (!path || strlen(path) == 0) return NULL;
+
+    // Resolve the path to an absolute path, assuming it's relative to the file
+    // it was found in:
+    char buf[PATH_MAX] = {0};
+    if (streq(path, "~") || strncmp(path, "~/", 2) == 0) {
+        char *resolved = realpath(heap_strf("%s%s", getenv("HOME"), path+1), buf);
+        if (resolved) return heap_str(resolved);
+    } else if (streq(path, ".") || strncmp(path, "./", 2) == 0) {
+        char *relative_dir = dirname(heap_str(relative_to));
+        char *resolved = realpath(heap_strf("%s/%s", relative_dir, path), buf);
+        if (resolved) return heap_str(resolved);
+    } else if (path[0] == '/') {
+        // Absolute path:
+        char *resolved = realpath(path, buf);
+        if (resolved) return heap_str(resolved);
+    } else {
+        // Relative path:
+        char *blpath = heap_str(getenv("SSSPATH"));
+        char *relative_dir = dirname(heap_str(relative_to));
+        for (char *dir; (dir = strsep(&blpath, ":")); ) {
+            if (dir[0] == '/') {
+                char *resolved = realpath(heap_strf("%s/%s", dir, path), buf);
+                if (resolved) return heap_str(resolved);
+            } else if (dir[0] == '~' && (dir[1] == '\0' || dir[1] == '/')) {
+                char *resolved = realpath(heap_strf("%s%s/%s", getenv("HOME"), dir, path), buf);
+                if (resolved) return heap_str(resolved);
+            } else if (streq(dir, ".") || strncmp(dir, "./", 2) == 0) {
+                char *resolved = realpath(heap_strf("%s/%s", relative_dir, path), buf);
+                if (resolved) return heap_str(resolved);
+            } else if (streq(dir, ".") || streq(dir, "..") || strncmp(dir, "./", 2) == 0 || strncmp(dir, "../", 3) == 0) {
+                char *resolved = realpath(heap_strf("%s/%s/%s", relative_dir, dir, path), buf);
+                if (resolved) return heap_str(resolved);
+            } else {
+                char *resolved = realpath(heap_strf("%s/%s", dir, path), buf);
+                if (resolved) return heap_str(resolved);
+            }
+        }
+    }
+    return NULL;
+}
+
+static sss_file_t *_load_file(const char* filename, FILE *file)
+{
+    if (!file) return NULL;
+
+    sss_file_t *ret = new(sss_file_t, .filename=filename);
+
+    size_t file_size = 0, line_cap = 0;
+    char *file_buf = NULL, *line_buf = NULL;
+    FILE *mem = open_memstream(&file_buf, &file_size);
+    int64_t line_len = 0;
+    while ((line_len = getline(&line_buf, &line_cap, file)) >= 0) {
+        sss_line_t line_info = {.offset=file_size, .indent=0, .is_empty=false};
+        char *p;
+        for (p = line_buf; *p == ' ' || *p == '\t'; ++p)
+            line_info.indent += *p == ' ' ? 1 : 4;
+        line_info.is_empty = *p != '\r' && *p != '\n';
+        if (ret->line_capacity <= ret->num_lines) {
+            ret->lines = GC_REALLOC(ret->lines, sizeof(sss_line_t)*(ret->line_capacity += 32));
+        }
+        ret->lines[ret->num_lines++] = line_info;
+        fwrite(line_buf, sizeof(char), line_len, mem);
+        fflush(mem);
+    }
+    fclose(file);
+
+    char *copy = GC_MALLOC_ATOMIC(file_size+1);
+    memcpy(copy, file_buf, file_size);
+    copy[file_size] = '\0';
+    ret->text = copy;
+    fclose(mem);
+
+    free(file_buf);
+    ret->relative_filename = filename;
+    if (filename && filename[0] != '<' && !streq(filename, "/dev/stdin")) {
+        filename = resolve_path(filename, ".");
+        // Convert to relative path (if applicable)
+        char buf[PATH_MAX];
+        char *cwd = getcwd(buf, sizeof(buf));
+        int64_t cwd_len = strlen(cwd);
+        if (strncmp(cwd, filename, cwd_len) == 0 && filename[cwd_len] == '/')
+            ret->relative_filename = &filename[cwd_len+1];
+    }
+    return ret;
+}
+
+//
+// Read an entire file into memory.
+//
+public sss_file_t *sss_load_file(const char* filename)
+{
+    FILE *file = filename[0] ? fopen(filename, "r") : stdin;
+    return _load_file(filename, file);
+}
+
+//
+// Create a virtual file from a string.
+//
+public sss_file_t *sss_spoof_file(const char* filename, const char *text)
+{
+    FILE *file = fmemopen((char*)text, strlen(text)+1, "r");
+    return _load_file(filename, file);
+}
+
+//
+// Given a pointer, determine which line number it points to (1-indexed)
+//
+public int64_t sss_get_line_number(sss_file_t *f, const char *p)
+{
+    // Binary search:
+    int64_t lo = 0, hi = (int64_t)f->num_lines-1;
+    if (p < f->text) return 0;
+    int64_t offset = (int64_t)(p - f->text);
+    while (lo <= hi) {
+        int64_t mid = (lo + hi) / 2;
+        sss_line_t *line = &f->lines[mid];
+        if (line->offset == offset)
+            return mid + 1;
+        else if (line->offset < offset)
+            lo = mid + 1;    
+        else if (line->offset > offset)
+            hi = mid - 1;
+    }
+    return lo; // Return the line number whose line starts closest before p
+}
+
+//
+// Given a pointer, determine which line column it points to.
+//
+public int64_t sss_get_line_column(sss_file_t *f, const char *p)
+{
+    int64_t line_no = sss_get_line_number(f, p);
+    sss_line_t *line = &f->lines[line_no-1];
+    return 1 + (int64_t)(p - (f->text + line->offset));
+}
+
+//
+// Given a pointer, get the indentation of the line it's on.
+//
+public int64_t sss_get_indent(sss_file_t *f, const char *p)
+{
+    int64_t line_no = sss_get_line_number(f, p);
+    sss_line_t *line = &f->lines[line_no-1];
+    return line->indent;
+}
+
+//
+// Return a pointer to the line with the specified line number (1-indexed)
+//
+public const char *sss_get_line(sss_file_t *f, int64_t line_number)
+{
+    if (line_number == 0 || line_number > (int64_t)f->num_lines) return NULL;
+    sss_line_t *line = &f->lines[line_number-1];
+    return f->text + line->offset;
+}
+
+//
+// Return a value like /foo:line:col
+//
+public const char *sss_get_file_pos(sss_file_t *f, const char *p)
+{
+    return heap_strf("%s:%ld:%ld", f->filename, sss_get_line_number(f, p), sss_get_line_column(f, p));
+}
+
+static int fputc_column(FILE *out, char c, char print_char, int *column)
+{
+    int printed = 0;
+    if (print_char == '\t') print_char = ' ';
+    if (c == '\t') {
+        for (int to_fill = tabstop - (*column % tabstop); to_fill > 0; --to_fill) {
+            printed += fputc(print_char, out);
+            ++*column;
+        }
+    } else {
+        printed += fputc(print_char, out);
+        ++*column;
+    }
+    return printed;
+}
+
+//
+// Print a span from a file
+//
+public int fprint_span(FILE *out, sss_file_t *file, const char *start, const char *end, const char *hl_color, int64_t context_lines, bool use_color)
+{
+    if (!file) return 0;
+
+    // Handle spans that come from multiple files:
+    if (start < file->text || start > file->text + file->len)
+        start = end;
+    if (end < file->text || end > file->text + file->len)
+        end = start;
+    // Just in case neither end of the span came from this file:
+    if (end < file->text || end > file->text + file->len)
+        start = end = file->text;
+
+    const char *lineno_fmt, *normal_color, *empty_marker;
+    bool print_carets = false;
+    int printed = 0;
+    if (use_color) {
+        lineno_fmt = "\x1b[0;2m%*lu\x1b(0\x78\x1b(B\x1b[m ";
+        normal_color = "\x1b[m";
+        empty_marker = "\x1b(0\x61\x1b(B";
+        printed += fprintf(out, "\x1b[33;4;1m%s\x1b[m\n", file->relative_filename);
+    } else {
+        lineno_fmt = "%*lu| ";
+        hl_color = "";
+        normal_color = "";
+        empty_marker = " ";
+        print_carets = true;
+        printed += fprintf(out, "%s\n", file->relative_filename);
+    }
+
+    if (context_lines == 0)
+        return fprintf(out, "%s%.*s%s", hl_color, (int)(end - start), start, normal_color);
+
+    int64_t start_line = sss_get_line_number(file, start),
+            end_line = sss_get_line_number(file, end);
+
+    int64_t first_line = start_line - (context_lines - 1),
+            last_line = end_line + (context_lines - 1);
+
+    if (first_line < 1) first_line = 1;
+    if (last_line > file->num_lines) last_line = file->num_lines;
+
+    int digits = 1;
+    for (int64_t i = last_line; i > 0; i /= 10) ++digits;
+
+    for (int64_t line_no = first_line; line_no <= last_line; ++line_no) {
+        if (line_no > first_line + 5 && line_no < last_line - 5) {
+            if (use_color)
+                printed += fprintf(out, "\x1b[0;2;3;4m     ... %ld lines omitted ...     \x1b[m\n", (last_line - first_line) - 11);
+            else
+                printed += fprintf(out, "     ... %ld lines omitted ...\n", (last_line - first_line) - 11);
+            line_no = last_line - 6;
+            continue;
+        }
+
+        printed += fprintf(out, lineno_fmt, digits, line_no);
+        const char *line = sss_get_line(file, line_no);
+        if (!line) break;
+
+        int column = 0;
+        const char *p = line;
+        // Before match
+        for (; *p && *p != '\r' && *p != '\n' && p < start; ++p)
+            printed += fputc_column(out, *p, *p, &column);
+
+        // Zero-width matches
+        if (p == start && start == end) {
+            printed += fprintf(out, "%s%s%s", hl_color, empty_marker, normal_color);
+            column += 1;
+        }
+
+        // Inside match
+        if (start <= p && p < end) {
+            printed += fputs(hl_color, out);
+            for (; *p && *p != '\r' && *p != '\n' && p < end; ++p)
+                printed += fputc_column(out, *p, *p, &column);
+            printed += fputs(normal_color, out);
+        }
+
+        // After match
+        for (; *p && *p != '\r' && *p != '\n'; ++p)
+            printed += fputc_column(out, *p, *p, &column);
+
+        printed += fprintf(out, "\n");
+
+        const char *eol = strchrnul(line, '\n');
+        if (print_carets && start >= line && start < eol && line <= start) {
+            for (int num = 0; num < digits; num++)
+                printed += fputc(' ', out);
+            printed += fputs(": ", out);
+            int column = 0;
+            for (const char *sp = line; *sp && *sp != '\n'; ++sp) {
+                char print_char;
+                if (sp < start)
+                    print_char = ' ';
+                else if (sp == start && sp == end)
+                    print_char = '^';
+                else if (sp >= start && sp < end)
+                    print_char = '-';
+                else
+                    print_char = ' ';
+                printed += fputc_column(out, *sp, print_char, &column);
+            }
+            printed += fputs("\n", out);
+        }
+    }
+    fflush(out);
+    return printed;
+}
+
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0